HomeMy WebLinkAboutCOM 0347.002 2004-2006 What is Direct-Use:
DIRECT HEAT UTILIZATION OF Heating and Cooling
GEOTHERMAL ENERGY • Swimming, bathing and balneology
• Space heating and cooling
- Including district energy systems
• Agriculture applications
John W. Lund -Greenhouse heating
• Aquaculture applications
Director -Fish pond antl raceway heating
Geo-Heat Center Industrial processes
Oregon Institute of Technology -Including food and grain drying
Klamath Falls, Oregon, USA • Geothermal heat pumps
Advantages of Direct-Use of
Uses of
Geothermal Heat Geothermal Energy
• Can use low- to intermediate
L ~µm n.. temperature resources (~300~F) Frequency ys n.:.ruo,r
s remoerawre
~'~~r~,I~ These resources are more wide- n,-,~,,,,,,p,.,,,,,rn
c e'ili L~~`~, ~ spread ( v. .~a
ML"JL °~f- Direct heat use no conversion - Ne Xfnd ,ex
i ~ I~ ~ ~ high efficiency) - •
-I~:y;~~~I; Useronventionalwater-well ~.8
~~&& rte; L~ }~i ~ drilling equlpment ~ ,e
~I'=~'$~ Use conventional, off-the-shelf
I~'~ ~'}:~11~ equipment d.......~.,._.AO
Minimum start-up-time ""rc~'a
Advantages of Direct-Use of Equipment
Geothermal Energy
• Can be used on a small scale ("mom • Often necessary to isolate geothermal
and pop operation") fluid to prevent corrosion or scaling
-Individual home Care taken to prevent oxygen from
-Single greenhouse entering system
-Single aquaculture pond Must take into account the chemistry of
• Can also be large scale operation the water, which may require a heat
-District heating exchanger to separate the geothermal
-Food and mineral ore drying from the secondary water.
Comm. N~o~.~~Z
Ref. To: ss~ E~
Retf. Data ~
j~Y
e..A.e we u•«MVU~nad
xwa.n.oe« iii
oap0~~
~ .,o•,~.« ~
~ - ~~w,m.~w.«
O wenna non ,m
i~ eo.,.,,• ieo4
For many tlvect uses of geothermal heat, hot water is pumped
from fatly shallow sources. The heat may be translerred to a
"working Iluitl," which could be potabe water or even air, using a
heat exchanger. (In other cases, such as aquaculture or spas,
the geINhennal water might be usetl directly, without a heat
exchanger)
Swimming, Bathing and
Balneology
• Main Users (past and present)
- Romans
- Chinese ~
-Ottomans (lurks)
- Japanese Unitetl
- Central Europeans A States
locations
- American Indians (Mexico and USA regions) t
- Pacific Islanders (Hawaii, Tahiti, Fiji, ela)
- Spa, Belgium
_ _ _ _ Space Conditioning
• Individual well for a building or several
t.~.; . buildings using pumps or downhole heat
exchangers connected to room convectors
Iceland and New Zealand
• Klamath Falls, Oregon (also snow melting)
. Reno, Nevada
Rotorua, New Zealand
,',-.j~;,.,~ Taupo, New Zealand
o- t. a=` Several Places in Turkey
2
ar ~ District Heating -Examples
• 18 locations in the US -total 100 MWt
• Reykjavik, Iceland-started 1930
- 190,000 people (99.9 % of city)
• 190° to 260°F water -supplied at 175°F
• Adequate to -15°F -oil tired booster station
•'4
62 wells providing 830 MWt
-~.'~,•-t Y„`w;,~ Large storage tanks for peaking
Agribusiness Applications
• Greenhouse heating (flowers, vegetables,
tree seedlings)
- 5 to 35% savings in heating costs
• Animal pen heating and cleaning
Reykjavik Iceland • $oil warming
Jr~ ~ Crop irrigation
Mushroom raising
- Soil and mulch sterilization
- Aquaculture
- 50 % increase in growth rate
- Catlish, shrimp, tilapia, eels, tropical fish
Agribusiness Applications ¢~•F A~, ~
ah R~-
• Should consider the chemistry of the water 3o Ibs/h
-effect on animals & plants 4Vyr
• Rotorua, New Zealand dried
- SoiVmulch sterilization
• Wairakei, New Zealand ,'~k I Tomato drying -Greece
-Malaysian prawns,
- alfalfa tlrying (pellets)
• Klamath Falls, OR
-Tree seedlings, tropical fish,
- potted flowers & vegetable starts rv q:
r
Tempe2lure "F '
LTNC50 T FT •B '~i
L 1
U I
E ~
a - - - Greenhouse heating systems -
I r - , .
a :5 F 1cuccmL_ 4T
° : :s
Tempe2ture "C
Temperature °F
50 e, - ~ 10^ Aquaculture -Example
- e~` Wairakel, New Zealand -freshwater prawns
- 19 ponds - 0.5 to 0.9 acre - 3 to 4 h. deep
~ r~u _ _ _ 75~F-effluent from power plant
E
E ~ _ _ _ _ . _ Produces 30 tons/yr
o . •_s Harvested after 9 months at 14 to 18 tails/Ib
5°~""0 Sold for US$17Ab wholesale and US$27/Ib
8 - ~ ~ retail
a r- - 90 % sold to restaurant on the property
` - 25,000 tourists/yr
°o .o ~e oo Future expansion to 100 acres and will
remperawre °c produce 400 tons/yr -income of US$ 6.7
million
Refrigeration
• Lithium bromide system (most
common -uses water as the
refrigerant)
- Supplies chilled water for space
entl process cooling -above the
freezing point
US and NEW Zealand -The higher temperature, the more - ~
efficient (can use geothermal - ~ .I
fluids below 200°F -however, ~
>200°F beaar for 100%
efliciency)
• Ammonia absorption used for
refrigeration below freezing
normally large capacity and
require geothermal
,J temperatures above 250°F
4
Heat Pumps (1)
• Ground source or geothermal heat pumps -J
(GSHP ar GHP) -uses 40 to 90°F ground .m„•,
temperature
• 50 to 100 % more efficient than air source,
since uses constant temperature resource
• Ground coupled
- Honzonlal in trenches 3 - 70 R deep
- Vertical in 4-inch diameter 150 - 200 ft. deep _
drillholes
- Others
• Ground water
- Using well or lake water IIIJJJ °°°tl
Heat Pumps (2) Industrial Applications
• Used for both heating and c0oling Oldest: Larderello, Italy-boric acid and borate
• Heated capacity of 3 kW to 1,500 kW compounds processed since 7790
-1 ton to 500 tons (of cooling capacity) New Zealand: pulp, paper and wood processing
• Solar vs geothermal heating???? at Kawerau -sulfur mining/processing
• Iceland: diatomaceous earth drying-Myvatn
• 27 countries - US the leader -Fish drying and sau productlon
• >500,000 units installed in US USA: vegetable dehydration (onion) -Nevada
• COP Of 4 gold extraction (heap leaching) -Nevada
?"A
Foatl Prmessln9 100°C Apartment
Builtlinq
~ 1~
US and China aeo-,gerarnn creanhwae*~
Piam
r
J,.b 2W~C $ RsM1 Farm
Power Plan)
- CascaOrtq to ma.wiza us 1
of Ne geolM1ermal energy
5
n"ua
HAWAII (1)
~9ANV
A + • Little need for space heating and cooling
+ - except for large buildings
xwui
(cooling)
wxr 'r-~ v
< ~ High temperature resource on Big Island
Geothermal
Direct-Use ""w"~~ ~~vr-~~°°° Low-to-moderate temp, resource on Maui
Possibilities T' Possible resource on Molokai and Oahu
HAWAII (2) HAWAII (3)
• Possible uses of geothermal on Hawaii Aquaculture pond heating
- aquaculture pond heating -constant 80°F temperature needed for optimum
growth of many species
- shade house bottom-heating - 100°F minimum temperature needed
- crop/timber drying - A 10°F temperature variation = 70 % growth rate
- refrigeration Greenhouse heating
-heat pumps for Cooling of resorts, -Cooling needed during day, heating at night
- 120°F minimum needetl for heating, 200°F for
public and commercial buildings cooling
- Spa and resort pools -Soil sterilizatioNpasteurization, 140°F
Temperature °F
_ - _
=a fie ~ HAWAII (4)
C~ekmf
100 - -
~ - - Crop/timber drying
- -Mainly food dehydration (pineapples and
- ~ coffee) and hard wood drying (koa, etc.)
° s~,,,m~ - -Need 200°F and above
~ _ - _ ~ _ - Refrigeration
g zo _ _ -Cooling -need 200°F and above
-Refrigeration -need 250°F and above
e----~ - -For cold storage (fish, pineapples, etc.)
,o ~o b m
r°mp°rawre °c
6
HAWAII (5) ~n ~ - ~ Jt UI,~
• Geothermal (ground-source) heat pumps
- Anywhere in Hawaii
- Need 40°F to 90°F ground or water temperature Nori O Puna Puna Geothermal
- Design for cooling load of larger buildings 1985-89 Research Center
- Saving 25 to 75 % of electricity load
• Spa and resort pools
- 70°F to 110°F mineral water desired
- Rest antl relaxation -health and well-being
- Tourist attraction
p
Thank You
7
OPTIONS AND QUESTIONS FOR DIRECT USE IN PUNA, HAWAII
Andrea T. Gill
Dept. of Business, Economic Development and Tourism
Strategic Industries Division
State of Hawaii
KEYWORDS
Direct use, Hawaii, low-temperature resources, Puna Geothermal Venture, regulations,
USA
ABSTRACT
Several options for the development of geothermal direct use enterprises in Puna,
Hawaii have been identified, including: 1) tapping waste heat from [he Puna Geothermal
Venture (PGV) power plant; 2) extracting heat from unused, existing exploratory wells;
and 3) drilling new shallow wells to the top of the aquifer. Shallow (less than 305 meters
deep) wells drilled in Puna during exploration for both potable water and geothermal
resources indicate aloes-temperature resource near the top of the aquifer, at or near sea
level. However, PGV is currently injecting waste fluids at 150° C; waste heat from this
source could be made available for direct utilization, obviating the need for new
production or injection wells. Several scenarios for developing heat for direct uses are
explored, along with their regulatory ramifications. Unanswered questions relating [o the
application of State and County laws and regulations are noted.
INTRODUCTION
Hawaii, unlike most other Western states, has less experience with the direct use
of geothermal heat than with geothermal electricity. Apart from the continuing
traditional uses of swimming and soaking in warm springs along the coast and enjoying
natural steam vents as saunas, the only documented direct uses of geothermal heat were
small experiments in the late 1980s known as the Community Geothermal Technology
Program (Beck, 1989).
In contrast, Hawaii's cxperence in geothermal exploration for electricity
generation dates back at least to the 1960s. Geothermal exploration by several different
companies and landowners eventually resulted in the successful establishment of a 30-
MW power plant by Puna Geothermal Venture (PGV), which became fully operational in
1993.
During the last four and a half decades, a number of wells have been drilled in
and near the Kilauea East Rift Zone (KERZ) for various purposes (see Figure 1). Their
temperatures, depths, and water chemistry provide insight into the geology of the rift
zone and the nature of geothermal resources in the Puna District of the Island of Hawaii.
Gill
This information is proving valuable as interest in non-electric uses of geothermal energy
increases.
Figure. 1: Wells in Lower Puna
The Hawaii County Geothermal Direct Use Working Group drafted this map depicting
wells in the Puna District near the current geothermal development area. These wells,
both deep and shallow, were drilled for a variety of purposes and provide insight into the
resources that could support direct use.
SHALLOW EXPLORATORY WELLS
Shallow wells for both potable water and geothermal power production have been
drilled at several dozen sites in the lower Puna area from near the town of Pahoa to the
easternmost point of the island, Cape Kumukahi. In this context, "shallow" generally
means depths of less than 305 meters (1,000 ft), usually to the top of the aquifer. This
water may or may not be hot, and may or may not be potable.
The chemistry of fluids tapped by the shallow wells is quite different from those
tapped by the deep wells drilled for geothermal production. The Hawaiian Islands'
highly fractured subsurface basalts allow seawater to penetrate deep within the interior
structure of the volcanic masses. Meteoric water percolates through the permeable soil
and fractured rock until it encounters seawater; [his less-dense fresh water then forms a
Ghyben-Herzberg lens, floating on top of the seawater. In the coastal areas, the fresh
water aquifer is fairly thin, encountered near or at sea level.
This basal water is encountered both north and south of the KERZ. Within the
KERZ, however, fresh water is considered both dike-confined and dike-controlled
(Iovenitti, 1990). The dike system within the rift provides both a source of heat and a
leaky boundary which controls the hydrology of the geothermal system; dikes and
possibly mineral deposition from seawater help exclude saline fluids from deeper
portions of the rift and partially isolate the groundwater within the eft from the larger
groundwatcr flow system (Thomas, 1985 and Scholl, 1993).
Magma sources heat both the meteoric water and the seawater that has infiltrated
the island mass; in places, the heated water rises to the top of the aquifer. Water
chemistry data show mixing of seawater and mcteoric water in a large thermal system
south of the KERZ (Janik, 1994).
Shallow wells near the coast, which tap the top of the aquifer, may thus encounter
a buoyant layer of warmed, somewhat saline water. If these wells were drilled slightly
deeper, they would probably penehate through the warmed layer, encountering reduced
temperatures. Although the KERZ structure is complex, with many fractures and
2
Gill
intrusive structures which can either enhance or limit fluid circulation, in general wells
deeper than 1,000 meters are required if ahigh-temperature resource is being sought.
In 1961, a major landowner in the Puna District of the Island of Hawaii drilled
four shallow exploratory geothermal wells. Dubbed Puna Thermal THl through TH4,
these wells were drilled to depths ranging from 66 meters to 210 meters and encountered
fluid temperatures ranging from 43° to 95° C neaz the top of the aquifer. These
temperatures are too low for viable electricity production, and deeper wells were not
considered at that time. These wells remain unutilized.
A number of shallow wells have also been drilled by both public and private
entities to locate potable water resources. Current potable water wells aze located north
and west of the geothermal production area, outside of the KERZ. With depths ranging
from approximately 130 meters to 245 meters, these wells penetrate roughly 20 meters
below mean sea level and produce potable water between 20° and 25° C.
Other water exploration wells were drilled in Puna, some within the KERZ or just
outside its approximate boundaries. With depths ranging from 14 to 102 meters,
extending from three to 30 meters below mean sea level, these wells show evidence of
seawater intrusion and aze considered too saline for the municipal water supply. In
addition, several wells' tempcratures were elevated, with the warmest at 56° C. Most of
these nonpotable water exploration wells aze currently unused, though one serves as a
backup water quality monitoring well for PGV's operations.
DEEP GEOTHERMAL EXPLORATION AND PRODUCTION WELLS
As the geothermal industry matured, deeper wells were drilled. Within the
KERZ, the first successful deep geothermal well was the public HGP-A well that
provided steam for a demonstration 3-MW power plant and encouraged private
exploration. HGP-A was completed in 1976 to a depth of 1,967 meters, achieving
temperatures of 360° C. When private developers encountered a producible resource
nearby with wells drilled in the 1980s, HGP-A's usefulness as a demonstration came to
an end. The well was permanently sealed in 1989.
Most of the 19 deep geothermal wells completed in the 1980s and `90s were
drilled for geothermal cxploration and production, although three were scientific
observation holes used to gather information on the subsurface geology in the KERZ.
Temperatures ranging from 220° C to over 350° C were recorded in the deep wells. Not
all of thcse wells were producible, however, and many have becn plugged.
Most major productive zones lie L,219 to 2,134 meters (4,000 to 7,000 ft) below
the ground surface (GeothermEx, 1994). The depths of most of the deep wells range
from approximately 1,400 meters to over 2,500 meters. Their mean depth below sea
level is 1,829 meters, although two wells, KS7 and KS8, encountered pressurized, hot
Fluids at comparatively shallow depths (KS8 reached a depth of 1,060 meters, 868 meters
below mcan sea level). These two wells are among those that have been plugged.
3
Gill
Two new wells are being drilled in mid-2005 by PGV. KS6 is intended to be a
fourth production well for the power plant, and KS 13 is expected to serve as a fourth
injection well.
REGULATORY FRAMEWORK FOR DIRECT USE
The State of Hawaii anticipated non-electric uses of geothermal heat when
establishing statutes and regulations in the 1980s. State law relaxes some regulatory
requirements if geothermal heat is to be used directly. For instance:
subzones: State land use laws specify appropriate uses in broad categories of
land, including urban, rural, agricultural and conservation. In addition, special
geothermal "subzones" were created. According to Hawaii Revised Statutes (HRS)
Section 205-5.1, exploration and development of geothermal resources for electricity
production can only occur in these four subzones, three of which aze in the KERZ. Non-
electric applications, however, aze only limited to a geothermal subzone if the land is
zoned for conservation purposes.
Definition of a geothermal resource: State law (HRS Section 182-1) defines a
"geothermal resource" as having temperatures above 150° F. Lower temperature fluids,
then, are not regulated as geothermal resources, and users of lower temperature fluids
need not obtain State geothermal exploration or well drilling permits. However, wells
drilled to tap geothermal fluids of 150° F or less must still be permitted as water wells by
[he State Commission on Water Resources. The permitting process is outlined at the
Commission's website (http://hawaii.gov/dlnr/cwrm/). A permit is necessary even if the
water is expected to be nonpotable (Nakano, pers. comm., 2005). In addition, the
disposal of fluids is still governed by Federal Environmental Protection Agency (EPA)
and State Department of Health rules on underground injection.
Despite having reduced regulatory requirements at the State level, developers of
geothermal direct use projects will be breaking new ground, both figuratively and
literally, since no one has yet permitted a direct use operation in Hawaii. The exact
application of State and County laws and regulations has yet to be exercised.
Currently, the County of Hawaii issues a Geothermal Resource Permit for
"geothermal development activities," including both research and commercial activities
and meaning "exploration, development, or production of electrical energy from
geothermal resources, or as otherwise defined in Hawaii Revised Statutes (HRS), Section
205-5. l
Since the language in the County's Rule 12, Geothermal Resource Permits,
specifically refers to the production of electrical energy, and since the referenced HRS
Section 205-5.1 relates to geothermal resource subzones and includes the exemptions for
direct use applications mentioned above, it is not unreasonable to assume that County
permitting will comport with State permitting. However, County Planning Department
4
Gill
staff opinion has not been rendered on the subject. Thus, potential County regulation of
direct use development remains an unknown factor in developing non-electric uses of
geothermal energy.
DIl2ECT USE RESOURCE OPTIONS
The County of Hawaii, supported by the State of Hawaii Department of Business,
Economic Development and Tourism with funding from the U.S. Department of Energy,
is investigating potential non-electric uses of geothermal heat in Puna. As part of this
effort, a Working Group has been formed to solicit comments and suggestions from the
community, and a feasibility study will be performed. The funding does not include any
implementation, such as drilling, experimentation or construction (Gill, 2004).
1n discussions to date, several options for the development of geothermal direct
use enterprises have been identified, including:
1) Tapping waste heat from Puna Geothermal Venture's power plant;
2) Extracting heat from unused, existing exploratory wells; and
3) Drilling new shallow wells to the top of the aquifer.
These options, and some of the questions they raise, will be explored briefly.
WASTE HEAT FROM PUNA GEOTHERMAL VENTURE (PGV)
PGV currently injects 3,000 gpm of fluids at or above 148° C (300° F) after
power production (Mizuno, pers. comm., 2005). The company is amenable to providing
waste heat for non-electric purposes, as long as its power plant operations are not
negatively affected and terms of its current lease and permit are adhered to. One critical
permit requirement is that geothermal fluids produced by PGV must be injected by PGV
within their lease area. This precludes export of the fluid itself beyond the lease
boundaries. However, extracting heat via a heat exchanger is a technically viable option,
and water-presumably from a potable public supply-thus heated could be piped
beyond the boundaries of PGV's lease.
The heat exchanger itself would be a critical component of such a system and
must be suitable for the chemistry and temperatures of the geothermal fluid. The
geothermal brine injected by PGV averages 127 mg/1 Si02 and 539 mg/1 H2S
(GeothennEx, 1994). Maintenance of the heat exchanger in view of the potential for
precipitation and deposition of dissolved solids will be essential.
Although County regulators have not yet thoroughly considered the ramifications
of such an export of heat from PGV, company officials believe that this activity would be
allowed under its current pcnnit. Assuming this is true, direct use applications would be
spared the expensive, regulated activities of drilling new production and injection wells.
A high temperature resource would be available without further exploration.
5
Gill
Waste fluids from PGV's operations are considerably hotter than [hose that have
historically been tapped by shallow wells, allowing a broad range of non-electric uses.
Further, PGV has indicated that the heat would be available a[ no cost (Mizuno, pers.
comm., 2004). A third party, however, would need to invest in the infrastructure-a heat
exchanger, pipes, and circulation pump, for instance-to extract the heat and transfer the
hot water to the location where it would be used. The capital cost of this equipment will
be estimated during the feasibility study phase of the State and County's direct use
project.
Another task of the feasibility study will be to identify a suitable location for
direct use enterprises utilizing waste heat from PGV. The company prefers such
activities to be sited outside of [heir 800-acre lease (Mizuno, pers. comm., 2004).
Adjoining properties are generally zoned for agricultural purposes, which would allow
enterprises such as fruit dehydration and growing media pasteurization.
One possible location is the four-acre Noii O Puna laboratory site adjacent to
PGV's lease. Previously the location of the HGP-A well and power plant, this was also
where the Community Geothermal Technology Program direct use experiments were
performed. Should Noii O Puna be refurbished for geothermal direct use enterprises, its
size may limit its desirability for some applications, such as extensive greenhousing.
WARM WATER FROM UNUSED, EXISTING WELLS
There are more than a dozen shallow wells in or near the KERZ, some of which
indicate elevated temperatures. PGV's three monitoring wells, for instance, have
temperatures ranging from 44° to 67° C.
The highest temperature recorded in a shallow exploratory well is 95° C, in TH3,
one of the wildcat wells drilled in 1961. Located on private agricultural land east of
PGV's facility, its condition and suitability for use aze unknown.
One of the existing shallow wells, Malama Ki, is owned by the University of
Hawaii (UH) and located on a UH agricultural experiment station south of PGV,
approximately two miles inland from the eastern Puna coast. Although the maximum
recorded temperature, 56° C, is fairly low for most purposes, the existence of the well has
raised some interest among UH agriculturalists. Among the applications suggested are
aquaculture and pre-export soil disinfestation of potted plants.
The State of Hawaii llepartrnent of Land and Natural Resources (DLNR) drilled
the Malama Ki well in (962 in an effort to identify potable water supplies. Although the
water is not potable, the well was used for monitoring through the mid-L990s and is
presently considered a standby monitoring well for PGV. Water chemistry data have
been published by the U.S. Geological Survey (USGS) (Janik, 1994), among others.
The ground surface elevation at Malama Ki's wellhead is 83.5 meters and the well
itself is 97.2 meters deep. Static water level is between 0.56 and 0.86 feet above mean sea
6
Gill
level. The bottom 14.6 meters (48 8) of the eight-inch casing is perforated (State of
Hawaii, 1962). The pumping test rate was 480 gpm, and temperatures during the test
ranged from 53° C (127.5° F) to 54.7°C (130.5°F). Malama Ki's chloride content ranged
from 3,811 to 6,887 mg/1 during monitoring by the USGS (Janik, 1994). The well, which
was percussion drilled, is covered by a removable metal lid. The status of the casing at
depth is unknown, though surface oxidation is evident in the exposed portion.
Because it is located within the Malama Ki UH agricultural experiment station,
the well, if utilized, must be used for agricultural purposes. The station itself has no
utility power, public water systems, or telephone service. The 189-acre Malama Ki
station was previously used extensively for species trials and is still home to a wide
variety of tropical fruit and nut trees, including cacao, macadamia, guava, sapodilla,
mangosteen, avocado, mango, papaya and lychee. Presently, USGS scientists use the old
administration building as a camping headquarters during their field research on bird
species.
Tapping the Malama Ki well for direct use poses a number of challenges. First,
the condition of the well and casing aze not known, nor the long-term sustainability of
temperature levels if the well is produced.
If the hot groundwater were to be pumped to the surface for direct use, a power
supply for the pump would be needed. Power for a pump would either require a new
utility line or an independent power system, such as one based on photovoltaics; both
options aze likely to be discouragingly expensive.
Water brought to the surface will eventually need to be disposed of. Normally,
the State of Hawaii Department of Health and the EPA require injection wells to protect
the aquifer.
Another option for withdrawing heat with reduced pumping costs is a downhole
heat exchanger (DHE). The eight-inch diameter of the existing casing would allow the
use of DHE. However, the casing is probably not undersized relative to [he well wall;
that is, there is probably not an annulus between the casing and the well wall which
would promote the formation of a convective cell necessary for good DHE performance.
One alternative might be the use of a convection promoter pipe (CPP). A CPP,
usual ly perforatcd at the top and bottom and inserted into a cased well, creates a pathway
that establishes one-cell thermal convection as long as reasonable permeability exists at
the well bottom. The presence of a CPP with a DHE has improved the heat output of the
DHE by 60°lo to 120°Ir~ in laboratory experiments, and demonstrations at Taupo, New
Zealand, have also been successful (Allis, 1980). It is possible that a 6-inch diameter
plastic pipe, into which a 2-inch DHE is inserted, would be sufficient to withdraw useable
heat (Culver, pers. comm., 2005).
7
Gill
It should be noted that geothermal DHE systems are typically used for domestic
water and space heating, not for agricultural applications, and their potential heat output
is less than that of pumped wells.
A DHE would need a source of water to circulate within [he system, picking up
heat from the well. Cuttently, there is no water supply in the Malama Ki station except
for some lazge storage cisterns near the old office buildings.
Further, the resource temperature encountered by the Malama Ki well is already
fairly low, 56° C. This would be reduced further by losses at the heat exchanger, limiting
the types of direct use applications that could be supported. Among the low-temperature
uses that might still be viable are aquaculture and greenhouse bottom heating.
On the positive side, however, a pump to circulate water through the DHE often
requires only a fraction of a horsepower, an order of magnitude less than that needed to
pump water out of the well. It may be feasible to supply this amount of electricity with
photovoltaics. Furthermore, in some DHE applications, natural convection alone is
sufficient to circulate the working fluid without a pump. A DHE would also make fluid
disposal unnecessary, since no geothermal water would be brought to the surface.
DRILLING NEW, DEDICATED SHALLOW WELLS FOR DIRECT USE
The third option for developing geothermal direct uses in Puna is, of course,
drilling new wells exclusively for non-electric purposes. Temperatures attained by
existing shallow wells indicate that water hot enough for a variety of applications may be
tapped at the top of the Puna aquifer; that is, at roughly sea level. The surface elevation
near PGV's operations is around 183 meters (600 ft), and declines to zero to the east.
The depth of a new well would be dictated primarily by the elevation of the wellhead.
Costs for drilling, casing and testing exploratory water wells, 16-20 inches in
diameter, currently range from $600 to $700 per foot. 1f the well is to be produced, the
pump, motor, piping, fittings, buildings, etc. can add another $1,000 to $1,200 per foot
(Young, pers. comm., 2005). Therefore, a new well in the general vicinity of PGV,
where shallow wells such as TH3 and MW2 have encountered temperatures between 67°
and 9~° C (153° and 203° F), might cost $1,000,000. However, note that a well tapping
temperatures above I50° F would be considered a geothermal well rather than a water
well by State regulations; equipment such as for blowout prevention would increase
costs. An injection well for the spent fluid would be an additional expense.
As in any other geothermal operation, of course, there is no guarantee that
sufficiently hot water would he encountered at shallow depths. Several miles north and
east of PGV, two wells-Kapoho Airstrip and SOH2-were drilled within a few hundred
feet of each other. The deep Scientific Observation Hole #2 (SOH2), which extended to
a depth of 2,073 meters, attained temperatures of 350° C (Olson, 1993). However, the
adjacent shallow exploratory water well, Kapoho Airstrip, is only 102 meters deep. The
highest recorded temperature was only 38° C (Janik, 1994).
8
Gil(
A third well, TH4, which is east of SOH2 and the Kapoho Airstrip well, was only
88 meters deep and recorded temperatures of 43° C.
Since the State DLNR's regulations have never been applied to direct use, there is
some question as to how the temperature limitation of 150° F will be interpreted Is it to
be measured at the bottom of the hole? If the well is permitted as a water well, not a
geothermal well, and unexpectedly encounters temperatures above 150° F, what
procedures would need to be followed? Would the developer then need to apply for a
Geothermal Exploration Permit and a Geothermal Well Drilling Permit? Would
additional equipment, such as blowout prevention, then need to be acquired,
unexpectedly increasing costs? Would the additional expenses and delays make direct
uses economically unviable?
These and the other unanswered questions listed above will be addressed as the
County/State geothermal direct use project continues.
ACKNOWLEDGEMENTS
Thanks to the following people for their valuable discussions and review of this
paper: Dr. Raymond Carr, energy coordinator with Hawaii County's Research and
Development Department; Mr. Gene Culver, Associate Director (retired) of the Geo-Heat
Center, Oregon Institute of Technology; Mr. Barry Mizuno, Owner's Representative for
Puna Geothermal Venture; Dr. Donald Thomas, Director of the University of Hawaii-
Hilo Center for the Study of Active Volcanoes; Ms. Priscilla Thompson, Energy Analyst
with DBEDT's Strategic Industries Division; Ms. Nami Wong of the State of Hawaii
DLNR Engineering Division; and Mr. Clyde Young, PE, of Hawaii County's Department
of Water Supply. The creation of the map of wells in Puna would not have been possible
without the professional expertise of Ms. Lisa Nahoopii, GIS analyst for Hawaii County's
Data Systems Department.
REFERENCES
Allis, Richard G. and R. James, 1980. "A Natural Convection Promoter for Geothermal
Wells." Geothermal Resources Council Transactions, v.4, p. 409-412.
Beck, Andrea Gill, 1989. "Experiments in Direct Use at Noi`i O Puna." Geothermal
Resources Council Transactions, v. 13, p. 3-9.
Culver, Gene, Oregon Institute of Technology Geo-Heat Center Personal
comnrunicatirnr; 4 May ?005.
GeothermEx, Inc., 1994. Annual Report: Geothermal Resources Assessment. State of
Hawaii Department of Business, Economic Development and Tourism.
9
Gill
Gill, Andrea T., 2004. "Prospective Direct Use Enterprises in Kapoho, Hawaii."
Geothermal Resources Council Transactions, v. 28, p. 85-89.
Iovenitti, J.L., 1990. "Shallow Ground Water Mapping in the Lower East Rift Zone
Kilauea Volcano, Hawaii." Geothermal Resources Council Transactions, v. 14, p.
699-703.
Janik, Cathy J., M. Nathenson, and M.A. Scholl, 1994. Chemistry of spring and well
waters on Kilauea Volcano, Hawaii, and vicinity. U.S. Department of the Interior,
U.S. Geological Survey Open-File Repoli 94-586.
Mizuno, Barry; Puna Geothermal Venture. Personal communication; 20 February 2004.
Mizuno, Barry; Puna Geothermal Venture. Personal communication; 21 April 2005.
Nakano, Dean; DLNR Commission on Water Resource Management. Personal
communication; 16 March 2005.
Olson, Harry J. and J. E. Deymonaz, 1993. "The Hawaiian Scientific Observation Hole
(SOH) Program Costs and His[ory of a Successful Slim Hole Drilling Program."
Geothermal Resources Council Transactions, v. 17, p. 443-450.
Scholl, M.A., C.J. Janik, S.E. Ingebritsen, J.P. Kauahikaua and F.A. Trusdell, 1993.
"Preliminary Results from an Isotope Hydrology Study of the Kilauea Volcano Area,
Hawaii." Geothermal Resources Council Transactions, v. 17, p. 187-194.
State of Hawaii Department of Land and Natural Resources, Division of Water and Land
Development, 1962. Circular C12: Summary of Drilling Logs and Pumping Test far
Malama-Ki Well 9-9, Malama-Ki, Puna, Hawaii.
Thomas, Donald M., 1985. "Characteristics of the Geothermal Resource Associated with
The Volcanic Systems In Hawaii." Geothermal Resources Council Transactions, v.
9, Part II, p. 417-422.
Young, Clyde; Hawaii County Department of Water Supply. Personal communication; 5
May 2005.
10
PROSPECTIVE DIRECT USE ENTERPRISES IN KAPOHO, HAWAII
Andrea T. Gill
Dept. of Business, Economic Development and Tourism, Strategic Industries Division
State of Hawaii
Keywords
Aquaculture, Balneology, Dehydration, Direct Use, Economic Development, Greenhouses,
Hawaii, Low-Temperature Resources, Pasteurization, Puna Geothermal Venture, Refrigeration,
USA
Abstract
The Puna District of the island of Hawaii encompasses the only Known Geothermal
Resource Area (KGRA) in the State of Hawaii. Its Kapoho region is also the location of the
state's sole geothermal power plant, the 30 MW Puna Geothermal Venture (PGV) facility.
Despite significant potential, there is negligible direct utilization of geothermal heat in Kapoho.
Direct use development is primarily hampered by a lack of awareness regarding the availability
of the resource and its benefits, and by the perceived cost of infrastructure. A regulatory
framework for geothermal development has been established, although County regulations do
not specifically address direct use.
The resources potentially available to direct use enterprises in Puna include thermal
groundwater from shallow wells and excess heat from PGV's operations. Water wells in the area
with depths less than 230 meters (750 ft) have recorded temperatures ranging up to 89°C
(193°F). PGV is supplied by several deep wells that have encountered fluids at temperatures up
to 342°C (648°F). Hot brine from the separator, at approximately 204°C (400°F), could be
tapped for direct use or additional power generation prior to reinjection.
Economic activity in Kapoho is primarily based on agriculture. Direct use offers value-
added opportunities for existing enterprises such as papaya farming, nursery operations and
commercial fishing, and can also provide the basis for new businesses. Direct use opportunities
are especially promising in Hawaii becausc of the exceptionally high costs of conventional
energy supplies, and because thcy can improve profitability, add value to products, increase
productivity and expand job opportunities in an environmentally benign manner.
Narrative
Although several areas with geothermal potential have bcen identified in the State of
Hawaii, the Big Island of Hawaii is the only island where geothermal resources have been
developed and where the community is actively engaged in geothermal issues. The island's
Puna District encompasses the only Known Geothermal Resource Area (KGRA) in the State and
is the location of the 30-MW Puna Geothermal Venture (PGV) power plant.
1
Gill
There is significant potential for geothermal direct use development in the Kapoho region
of Puna that is primarily hampered by a lack of awareness regazding the availability of the
resource and its benefits to business ventures, as well as the perceived high capital cost of wells
and other infrastructure. Direct use development in Puna could encourage activities elsewhere in
Hawaii and other Pacific island jurisdictions such as the Commonwealth of the Northern
Mariana Islands and American Samoa.
Puna Geothermal Venture, Hawaii's sole geothermal power plan[, has been operating
since 1993. However, despite the prevalence of shallow thermal groundwater in the area and the
willingness of PGV to provide hot fluid for non-electric uses from its system, the only current
direct uses of the abundant geothermal resource are a small aquaculture operation and some
steam vents and warm springs on public and private properties used for recreational and/or
therapeutic purposes.
Direct Use Working Group
To raise awareness of and interest in non-electric uses of geothermal energy, [he State of
Hawaii Department of Business, Economic Development, and Tourism and the County of
Hawaii, along with PGV, the University of Hawaii Center for the Study of Active Volcanoes
(CSAV), and the Oregon Institute of Technology Geo-Heat Center, are establishing a Hawaii
County Geothermal Direct Use Working Group with support from the U.S. Department of
Energy's GeoPowering the West program. The Working Group will have broad representation
including: residents, businesses and landowners in the community; PGV; agricultural commodity
groups and extension agents; government representatives; and geothermal experts.
The professionally facilitated Working Group will focus on disseminating information on
direct use applications as well as collecting and transmitting community comments to the
County. A proactive, collaborative approach to gathering input, with both informal networking
and formal meetings, will be applied. This collegial method will increase the acceptability of
direct use development to the community by reflecting its needs and preferences.
Public, non-technical educational workshops, to which all interested parties are invited,
will be convened to supplement the Working Group's information dissemination and public
input functions. Topics such as geothermal technology, the economics of geothermal
development, access and permitting will also be addressed.
The County can benefit from the Working Group's input regarding the existing
Geothermal Asset Fund and Royalty Fund requirements. Although both are intended to benefit
the community adjacent to geothermal development and mitigate its impacts, there are strict
guidelines for determining eligibility and release of monies. Each fund currently holds
approximately $1? million. PGV pays $50,000 annually to the Asset Fund, and a portion of its
annual revenues goes to the Royalty Fund (Mizuno, pers. comm., 2004). To date, only $6,500 of
the Asset Fund has been granted for a resident's claim and the maintenance of a community
group's emissions monitoring equipment.
2
Gill
The intent of the Geothermal Relocation Program is to relocate certain owner-occupants
residing near the geothermal power plant, if they so request. It is funded by proceeds from the
geothermal royalties received from the Stale Department of Land and Natural Resources, the sale
of properties purchased, and rental fees from any of the properties purchased under this program.
The fund was debited approximately $209,000 for net expenses after the purchase and resale of
four homes under this program between 1999 and 2004 (Kawaha, pers. comm., 2004).
Available Geothermal Resources in Kapoho
PGV has acquired permits allowing eventual expansion to 60 MW, and can add up to
seven new wells under existing permitting. Many direct use applications are quite modest,
implying that PGV's excess thermal resource could support a fairly extensive range of activities.
For instance, depending on the size of the operation and the local climate, geothermally heated
greenhouses in other states require from 0.6 MWt to 1.5 MWt per acre, and aquaculture
operations can require 2 to 4 MWt per acre (Lund, pers. comm., 2004). Hawaii's subtropical
climate would substantially reduce the thermal demands for similaz enterprises of equivalent
scale.
In 2001, PGV leased Noi`i O Puna (NOP), the former Puna Research Center, from the
State's Natural Energy Laboratory of Hawaii Authority (Boyd et al, 2002). NOP is a 1.6-hectare
(4 ac) facility adjacent to the approximately 324 hectares (800 ac) PGV has leased for its
operations. The research center has been inactive since the HGP-A well was closed in 1989 and
is currently used by PGV for storage. NOP is a potential geothermal direct use incubator park
site. PGV is willing to provide heat to NOP for direct utilization, as long as it does not
negatively affect power plant operations (Mizuno, pers. comm., 2004).
PGV's power plant is supplied by several deep wells having total depths greater than
1,372 meters (4,500 ft) (GeothermEx, 2000). These wells have encountered fluids at
temperatures ranging between 335°C and 342°C (635°F - 648°F). Other deep wells in the
vicinity of the PGV lease have encountered temperatures as high as 373°C (703°F).
Fluids from these deep wells are now utilized by PGV's power plant. After electricity
generation, the fluids-a mixture of condensate and brine from the separator-aze reinjected at
temperatures ranging between 149°C and 204°C (300°F - 400°F). Brine from the separator is at
the higher end of that range, and could be tapped for additional uses prior to mixing and
reinjection.
The Kapoho region overlies the Kilauea East Rift Zone (KERZ). The State Department
of Land and Natural Resources has designated four Geothermal Resource Subzones statewide.
There are three Subzones in KERZ-the Kapoho, Kamaili, and Kilauea Middle East Rift
Subzones-as well as the Haleakala Southwest Rift Subzone on Maui. The Kapoho Subzone
lies mainly within an area that is estimated to have a 95% probability of ahigh-temperature
resource (GeothermEx, 2000). Water wells in the area having depths less than 229 meters (750
ft) have recorded temperatures ranging up to 89.4°C (192.9°F) as well as elevated mineral
content indicative of limited ocean water intrusion (GeothermEx, 1999). There are
approximately one dozen known wells and springs in [he Kapoho area with measured
3
Gill
groundwater temperatures of at least 26°C (78.8°F), and ranging up to 55°C (131°F) (Moreau,
1980). It is possible that a direct use enterprise park, or an individual enterprise, could utilize hot
groundwater from independent wells, not part of PGV's operations.
Kapoho's Current Economic Activities and Direct Use Clpportunities
Economic activity in Kapoho is primarily agricultural. Direct use offers value-added
opportunities for existing enterprises, and can also provide the basis for new businesses. Direct
use opportunities are especially promising in Hawaii because of the exceptionally high costs of
conventional energy supplies such as electricity and propane gas. The community discussions
aze expected to reflect a broad spectrum of entrepreneurial interests, such as those below.
1) Fruit dehydration
Geothermal heat can be used for fruit dehydration or other processing, providing value-
added options which can improve the farmers' profitability. Of the roughly 810 agricultural
hectazes (2,000 ac) in Kapoho, up to 70% is cultivated, mostly in papaya (Hopkins, pers. comm.,
2004). The average production of salable fruit in 2001 was 30,000 kg per hectare (26,50016/ac)
(Data Book 2003), resulting in an estimated 14.4 million kilograms (31.8 million lb) of
mazketable fresh papaya for the region that year.
However, an equivalent amount of papaya is not salable as fresh fruit due to reasons such
as small size or irregular shape (Hopkins, pers. comm., 2004). Most of these culls are currently
discazded. The dehydration of cull fruit would provide avalue-added option. Dried papaya
slices and chunks are marketable as snack foods, while dehydrated papaya powder can be sold as
a nutritional supplement and digestive aid due to the enzyme, papain, which it contains.
An eazlier study estimated that the capital cost of a papaya drying facility would be
$200,000 for a plant with a 1,000 pound per day capacity (Okahaza/Shigeoka, 1982). A larger
capacity plant, processing between one and two million pounds of papaya annually for a national
mazket, was reported to be only marginally economic (Chen, 1982). However, market
conditions today are substantially different, and the distribution network for these products has
become more diffuse through e-commerce. A local fruit producers' cooperative may find that it
can transform unmarketable culls into a significant revenue stream.
Besides papaya, other crops are grown in Kapoho, mostly the products of small,
diversified farming operations. They include organic tropical fruits such as avocado and
rambu[an, as well as banana and macadamia nuts. Some of these crops could be dried.
2) Cold storage, refrigeration, and ice making
Puna District is known for its flowers and ornamental plants. A sizeable vanda orchid
farm is located approximately eight kilometers (5 mi) east of PGV, and some small businesses in
the area aze dcvotcd to flower packing and sales. Cool storagc is necessary.to preserve the
freshness of flowers prior to shipping.
4
Gill
Pohoiki Bay, eight km (5 mi) to the southeast of PGV, is the County's third lazgest
commercial fishing port. In 2002, 149,371 kg (329,3021b) of fish were landed at Pohoiki,
valued at $667,932 (Data Book 2003). However, the neazest source of ice is in Hilo, over 42 km
(26 mi) away. Ice, which is necessary to keep both bait and the catch fresh, can melt as much as
20% during transport from the Hilo ice plant (Hirai & Assoc., 1983). A nearby icehouse and
cold storage facility would improve the quality of the fish and the productivity of the fishermen.
3) Aquaculture
The only current business utilizing warm groundwater in Kapoho for direct use is an
aquaculture enterprise, Tropical Ponds Hawaii, which raises tropical ornamental fish such as
swordtails, platys, guppies, endlers and gourami. They operate 32 ponds on roughly 0.8 hectazes
(2 ac), and plan to add another 40 ponds in the near future. The water source is 43°C (110°F)
groundwater from a 213-meter (700 ft) shallow well adjacent to PGV's power plant. Between
35,000 and 70,000 gallons per week are utilized. Although most of the water is cooled to
ambient temperatures-which range from the low 70s to low 80s Fahrenheit- before entering
the ponds, water at approximately 38°C (100°F) is added to breeding ponds and hatchery tanks
to stimulate breeding. The slightly saline water is also conducive to fish health by promoting the
growth of protective "slime coats" and controlling algae in the ponds (Kern, pers. comm., 2004).
Even in Hawaii's mild climate, aquaculture pond temperatures can fluctuate
approximately 5.5°C (10°F) seasonally. Using geothermal fluids to stabilize the temperature
within 2-3°F' of optimum can significantly increase the growth rates of many species of fish.
4) Greenhouse bottom heating
Raising nursery products, including foliage, potted flowering plants, bedding plants, and
landscape plants, is a major activity in the Puna District. In 2002, the value of these products in
the County-excluding cut flowers, orchids and lei flowers--exceeded $23.8 million (Data Book
2003).
From 1986 to 1989, a small demonstration greenhouse, using a geothermal bottom
heating system, operated at the NOP research center. The growing medium was kept at 29°C to
32°C (85°F - 90°F) at the heated greenhouse, while at a nearby control facility it was
approximately 21°C (70°F). The nursery operator identified over a dozen species of ornamental
palms that grew significantly better in heated media (Beck, 1989). Not only did the seedlings
reach transplant size more quickly-sometimes several months before non-heated controls-but
germination rates also improved.
5) Processing other agricultural products
Geothermal heat can dry lumber. Having a limited number of operating lumber kilns
handicaps the State's forest industry, which is centered in Hawaii County. Existing kilns' energy
costs are discouragingly high. Many businesses choose to air dry their lumber, which may take
months or even years, or export wood for kiln drying out of state. Providing acost-competitive
local kiln would offer opportunities for adding value to the timber crop.
5
Gill
Geothermal heat can also be used to dry macadamia nuts, a major crop in Puna District.
Currently, the Mauna Loa Macadamia Nut processing plant in Keaau, approximately 24 km (15
mi) west of PGV, utilizes its waste biomass for drying, roasting and other process heat. A
smaller-scale dryer at a direct use enterprise pazk could allow small operators to independently
process their crops for market.
Hcat could also be used to process animal and fish feed for local animal husbandry and
aquaculture operations. A 1980 study investigated the feasibility of a cattle feed mill that would
process dehydrated feed from sugarcane leaves for export (Moreau, 1980). Other products, such
as cacao beans, coffee, kukui nuts, fish or meat could also utilize a dehydration facility.
6) Pasteurization or sterilization of growing media
Iawaii's extensive nursery industry raises foliage, flowers, ornamentals and other plants
in shade houses and greenhouses. If the plants are intended for export, special steps must be
taken to avoid the transport of soil organisms such as nematodes. Plants must be grown on
raised benches in sterile or pasteurized media, essentially all of which is currently imported.
Mushroom culture, a small facet of Hawaii agriculture that is increasing in importance, also
requires uncontaminated media.
If local materials could be pasteurized for growing media, imports could be reduced.
Growing media pasteurization has been demonstrated on a small scale using raw geothermal
steam (Beck, 1989). Locally available materials such as volcanic cinder, shredded green waste,
and sawdust could be steamed until extant pathogens were killed.
7) Balneology
Warm springs near Kawaihae, on Hawaii's western coast were mentioned by the explorer
and missionary William Ellis in 1826 as being used by the local residents, some of whom
attributed medicinal qualities to the water (Woodruff & Takahashi, 1990). Currently, natural
geothermally heated brackish ponds aze attractions at a County coastal pazk in the Kapoho
region, as well as in private residential developments along the Puna coast.
In part due to the popularity of "onsen," naturally heated pools and bathing facilities in
Japan, and the large number of Japanese visitors to Hawaii, geothermal spas have becn the
subject of several studies and have been proposed for the Kapoho area by at least one private
developer. An analysis performed for the State in 1988 noted that Hawaii is ideally suited for the
health spa industry, and that a major potential market for health spas exists among typical Hawaii
visitors (GrantThornton, 1988).
"I~hc temperature and chemical composition of the naturally heated groundwater in the
Kapoho region are within the range of spas developed elsewhere in the world (Woodruff &
Takahashi, 1990). Other regions on the island of Hawaii, notably the area around the town of
Pahala near Kilauea's southwest rift zone, as well as other Hawaiian islands may also have
suitable thermal groundwater resources (GeothermEx, 1999).
6
Gill
8) Other ventures
Other ideas for the direct use of geothermal heat in Hawaii have been suggested or
investigated. These have included the production of cement bonded wallboard, ethanol
distillation, freeze drying of Kona coffee or other products, protein recovery from green leaf
crops for animal feed, and milk pasteurization (Moreau, 1980). Geothermal heat has also been
suggested as a method to disinfest papayas of fruit flies prior to export (Beck, 1989) or to supply
heat to a community incubator kitchen (Mizuno, pers. comm., 2004).
Heat pumps, one of the most extensive uses of geothermal energy in the U.S., can
provide both space heating and cooling. Cooling is a major load for most commercial buildings
in Hawaii.
Untreated geothermal steam has also been used to fix dyes in hand painted silk, while
hand blown glass formulae and cast bronze refractory materials utilized the silica byproduct of
the now-closed HGP-A well (Beck, 1989). Other artistic uses of the geothermal resource may be
identified.
Current Regulatory F,nvironment
There are six major aspects of geothermal regulations in Hawaii: 1) the definition of a
geothermal resourcc; 2) land use districts, including Geothermal Resource Subzones; 3)
Geothermal Resource Permits; 4) drilling permits; 5) underground injection control permits; and
6) air quality permits.
According to the Hawaii Revised Statutes (HRS) Section 182-1, a "geothermal resource"
is defined to exclude water having a temperature of 150°F or less. Thus, low-temperature
resources are exempt from the specific regulations governing Subzones and State geothermal
drilling permits.
Groundwater in excess of 65.5°C (150°F) could also be tapped for geothermal direct use.
State law allows these higher-temperature direct uses to be located regardless of Subzone
boundaries, as long as the developmcnt is within urban, rural, or agricultural land use districts. If
the development is within a conservation district, it must then be located within a Subzone.
If the direct use developer is working with groundwater that is no hotter than 65.5°C
(150°F), the State permitting process is the same as for a normal water well. The Commission
on Water Resource Management, within the Department of Land and Natural Resources
(DLNR), would handle the permits (GeothermEx, 1999). If it is expected that groundwater
hotter than (5.5°C (I50°F) will he encountered, the well would be considered a geothermal well,
and the developer will need to obtain a Geothermal Exploration Permit and a Geothermal Wcll
Drilling Permit, pursuant to the terms of HRS Chapters 174C and 182, and the corresponding set
of DLNR Administrative Rules (Title 13, Chapter 183). The Land Division, 1?ngineering Branch
of DLNR is responsible for regulating geothermal development.
7
Gill
The County of Hawaii requires that a Geothermal Resource Permit (GRP) be secured
from the Planning Commission for any geothermal development activities in a Geothermal
Resource Subzone within a State agricultural, rural or urban land use district. Geothermal
development activities include reseazch or commercialization purposes, exploration development
or production of electrical energy from geothermal resources, or as otherwise defined in HRS,
Section 205-5.1. Further review of the Planning Commission rules would need to be conducted
in order to determine whether a GRP would be required for any geothermal direct use
development.
Injection wells are regulated by the State Department of Health (DOH) under HRS
Chapter 340E and the corresponding DOH Administrative Rules (Title 11, Chapter 23). Water
from some direct use applications, such as spas, might require an injection well permit
(GeothermEx, 1999).
For many direct use developments, an air quality permit would not be required. It is
unlikely that hydrogen sulfide, present in deep geothermal fluids, will be a significant factor in
shallow groundwater. The ambient air quality standazds for the State are given in HRS 342B and
the corresponding DOH Administrative Rules (Title 11, Chapters 59 and 60). Under these rules,
the limit for hydrogen sulfide in ambient air is 25 parts per billion, averaged over cone-hour
period (GeothermEx, 1999).
Expected Results
The following actions are among the public information program's expected results.
A) Investment in individual direct use enterprises. Private businesses, after Teaming the
benefits of direct use to their operations, may make independent investments in
infrastructure and facilities to take advantage of geothermal heat.
B) Investment in an incubator/enterprise pazk. Public and private entities may choose to
jointly or independently establish a geothermal direcC utilization enterprise park.
C) Modification of County and/or State regulations to encourage the direct utilization of
geothermal resources. Public discussion and input are expected to generate ideas
regarding appropriate permitting for direct use projects. These ideas will be
considered by the appropriate government agencies.
D) Use of public funds to support direct use. The outreach efforts may result in local
businesses faking advantage of existing public funding programs, including those
managed by the U.S. Department of Agriculture. Furthermore, community input may
suggest that the County modify its regulations to appropriate portions of the
Geothermal Asset Fund and/or Geothermal Royalty Fund to support direct use
activities.
Acknowledgements
8
Gi Il
The members of the project team, including Susan Gagorik, Margarita Hopkins, Alice
Kawaha, Dr. John Lund, and Barry Mizuno, contributed substantially to this paper during
reviews and interviews. In addition to the team members cited as sources of specific technical
information, Dr. Raymond Carr, energy coordinator for the Hawaii County Reseazch and
Development Department, and Dr. Donald Thomas, director of CSAV, provided extensive input
and valuable suggestions.
References
Beck, Andrea Gill, 1989. "Experiments in Direct Use at Noi`i O Puna." Geothermal Resources
Council Transactions, vol. 13; October 1989, p. 3-9.
Boyd, Tonya L., D. Thomas and A. Gill, 2002. "Hawaii and Geothermal, What Has Been
Happening?" Geo-Heat Center Quarterly Bulletin, v. 23, no. 3, p. 11-21.
Chen, Bill H. et al, 1982. Utilization of Geotlermal Heat in Tropical Fruit Drying Process.
State of Hawaii Department of Business, Economic Levelopment and Tourism.
Data Book 2003. County of Hawaii. Online.
<ht~t ://co.hawaii.hi.us/databook current/dbooktoo,htm>.
GeothermEx, Inc., 1999. Development Opportunities for Geothermal Spas in the State of
Hawaii. State of Hawaii Department of Business, Economic Development and Tourism.
GeothermEx, Inc., 2000. Update of the Statewide Geothermal Resource Assessment of Hawaii.
State of Hawaii Department of Business, Economic Development and Tourism.
GrantThornton, 1988. Business Opportunity Report Hawaii: Health Spas. Prepazed for Hawaii
Department of Business and Economic Development, and the Chamber of Commerce of
Hawaii.
Hirai, W.A. & Associates, Inc., 1983. Final Report. Feasibility of an Ice-Making and Cold
Storage Facility Using Geothermal Waste Heat in Puna District, Island of Hawaii.
County of Hawaii Department of Reseazch and Development.
Hopkins, Mazgarita; County of Hawaii Research and Development Department. Personal
communication; 9 February 2004.
Kawaha, Alice and S. Gagorik; County of Hawaii Planning Department. Personal
communication; 17 February 2004.
Kern, Robert; Tropical Ponds Hawaii. Personal communication; 3 March 2004.
Lund, John; Oregon Institute of Technology Geo-Heat Center. Personal communication; 29
March 2004.
Mizuno, Barry; Puna Geothermal Venture. Personal communication; 20 February 2004.
Moreau, James W., 1980. Final Report. Pahoa Geothermal Industrial Park. Engineering and
Economic Analv.ris for Direct Applications of Geothermal Energy in an Ltdustrial Park
ar Pahoa, Hawaii. Prepared by Hawaiian Dredging and Construction Company for the
U.S. Department of Energy.
Okahar~Shigeoka & Associates, 1982. A Cost Stricture for a Tropical Fruit Drying Pilot Plmu
1Jtilizing Geothermal Wa.r[e Heat. State of Hawaii Department of Business, Economic
Development and Tourism.
Woodruff, James L. and P. Takahashi, 1990. "Geothermal Spas: A New Business Opportunity
in Hawaii." Geothermal Resources Council Transactions, v. 14, Part I, p. 819-825.
9
GEOTHERMAL DIRECT USE
COMMUNITY MEETINGS
Dr. John Lund, director of the Oregon Institute of Technology's Geo-Heat Center has
been invited to the Big Island to share his knowledge of non-electric uses of geothermal
energy.
Dr. Lund's experiences range from district heating projects in Klamath Falls, Oregon,
site of the Geo-Heat Center, to the popular "Blue Lagoon" swimming pond in Iceland
and acres of chrysanthemum-filled heated greenhouses in Utah. One of his recent
projects was assisting the Confederated Tribes of Warm Spring Reservation in Oregon
with the development of a geothermal swimming pool and hot tubs for tribal use as well
as a visitor attraction. For more information on direct use of geothermal heat, visit the
Geo-Heat Center's website at http://geoheat.oit.edu.
Among the enterprises that might benefit from the direct use of geothermal heat on the
Big Island are alumber-drying kiln, dehydrators for papaya and other produce, and
facilities to pasteurize growing media for greenhouses.
Dr. Lund's presentations are part of a continuing investigation into geothermal direct use
undertaken by the County of Hawaii. The following meetings are open to the public:
1. The County Council's Committee on Human Services and Economic Development,
County Council Chambers, Tuesday, August 16`h, 2005, 10:00 am -11:00 am
2. Agricultural Commodity and Business Groups, Cooperative Extension Service
Conference Room A, Tuesday, August 16, 2005, 1:00 pm - 2:30 pm, for information
contact Margarita Hopkins at 961-8366 or mhopkins~co.hawaii.hi.us.
3. Community Meeting, Tuesday, August 16, 2005, Pahoa Community Center, 5:00
pm - 7:30 pm, for information contact the Hawaii County Resource Center at 961-
8085 or hcrcC~co.hawaii.hi.us.
4. Rotary Club of Hilo Bay, Naniloa Hotel, 10`h floor, Wednesday, August 17, 2005,
6:45 am - 8:00 am, $5.00 for coffee and presentation, $8.50 for breakfast and
presentation, for reservations call Julie at 990-0426 or Anita at 756-2119.
D[RECT HEAT UTILIZATION OF GEOTHERMAL RESOURCES
John W. Lund
Geo-Heat Center, Oregon Institute of Technology, Klamath Falls, OR, USA
Keywords: Geothermal, direct use, balneology, space heating, district heating, greenhouses, aquaculture, industrial
processes, heat pumps
Abstractr Direct utilization of geothermal energy consists systems, 5% are above 150°C, and 85°io are below 90°C
of various forms for heating and cooling instead of (Muffler, 1979). In fact, almost every country in the
converting the energy for electric power generation. The world has some low-temperature systems; while, only a
major areas of direct utilization are (1) swimming, few have accessible high-temperature systems.
bathing and balneology, (2) space heating and cooling
includingdtstnctheating,(3)agriculmreapplieations,(4) UTILIZATION
aquaculture applications, (5) industrial processes, and (6)
heat pumps. Major direct utilisation projects exploiting Traditionally, direct use of geothermal energy
geothermal energy exist in about 60 countries, and [he has been on small scale by individuals. More recent
estimated installed thermal power is 16,200 MWt utilizing developments involve large-scale projects, such as district
over 64,000 kg/s of fluid. The worldwide thermal energy heating (Iceland and France), greenhouse complexes
used is estimated to be alt least 162,000 TJ/yr (45,000 (Hungary and Russia), or major industrial use (New
GWh/yr)--saving 11.4 million TOE/yr. The majority of Zealand and the US.). Heat exchangers are also
this energy use is for space heating (37°i.„), and swimming becoming more efficient and better adapted to geothermal
and bathing 122%). In the USA, the installed thermal projects, allowing use of lower temperature water and
power is 5,366 MWt, and the annual energy use is 20,300 highly saline fluids. Heat pumps utilizing very luw-
TJ(5,640GWh). The majority of the use (59%)isfor the temperature fluids have extended geothermal
heat pumps (both ground coupled and water source), with developments into traditionally non-geothermal countries
bathing and svimming, and fish farming each supplying such as France, Switzerland and Sweden, as well as areas
about 13%. of the mid-westemand easternU.S. Most equipment used
in these projects arc of standard, off-the-shelf design and
INTRODUCTION need only slight modifications to handle geothcmtal Fluids
(Gudmundsson and Lund, 1985, and Geo-Heat Center
Direct or non-electric utilization of geothermal Quarterly Bulletin, 19(1), 1997).
energy refers to the immediate use of the heat energy Worldwide (Lund and Freeston, 2000), the
rather than to its conversion to some other form such as installed capacity of direct geothermal utilization is
electrical energy. The primary forms of direct use include 16,200 MWt and the energy use is about 162,000 TJ/yr
swimming, bathing and balneology (therapeutic use), (45,000 GWIv'yr) distributed among 60 countries (Table
space heating and cooling including district heating, 1). This amounts to saving an equivalent 11.4 million
agriculture (mainly greenhouse heating and some anima] tonnes of fuel oil per year (TOE). The distribution of the
husbandry). aquaculture (mainly fish pond and raceway energy use among the various types of use is shown in
heating), industrial processes, and heat pumps (for both Figure 1 for the entire world, and for comparison,
heating and cooling). In general, the geothermal fluid the U.S. (Figure 2). The installed capacity in the U.S.
temperatures required for direct heat use are lower than (2000) is 5366 MWt and the annual energy use is 20,300
those for economic electric power generation. TJ (5,640 GWh), saving 3.94 million TOE (Lund and
Most direct use applications use geothermal Boyd, 2000). In[emationally, the largest uses arc for
fluids in the low-to-moderate remperature range between space heating (37%) (3i4 of which is due to district
50° and 150°C, and in general, the reservoir can be heating), and for swimming, bathing and balneology
exploited by conventional water well drilling equipment. (22'%); whereas, in the U.S.. the largest use is for
I-ow-temperature systems are also more widespread than gcothemtal heat pumps (59°%). In comparison, Iceland's
high-temperature systems (above 150°C); so, [hey are largest geothernal energy use is 77% for space heating
more likely to be located near potential users. In the U.S., 15,600 TJ/yr (4334 GWh/yr)--primarily with district
for example, of the 1,350 known or identified geothermal heating systems (Ragnarssou, 2000).
Others (0.59%)
Snow Melting/Air Cond. (0.60%)
Heat Pumps (14.33%)
,x,t* ;
Bathing (22.15%) M~+`
a
e-, . ~ ~ 'Fc'.
a~F~'
Industrial (6.50%)
Ag. Drying (0.59%)
Aquaculture (6.64%) Space Heating (36.85%)
Greenhouses (11.75%)
Figure 1. Distribution of geothermal energy use in the H~orld.
bathinglswimming (12.30 % )
-:~.~~~~4~ r snow melt/cooling (0.08%)
.
~ space heating (7.28%)
ag drying (1.50%)
fi14 .
' greenhouses (5.58%)
i,r
heat pumps (59.11%) -
aquaculture (13.77%)
a',~t .
o-.. ; - industrial (0.36°/ )
Figure 2. Distribution of geothermal energy use in the L'.S.
Table 1. Summary of direct-use data from individual countries. blanks indicate no value re orted)
Flow Capacity Annual Utilization Capacity Wells Person- Funds
Count k s MWI TJ/ GWh/ factor drilled years million $
AI eria 516 100.0 1,586 441 0.50 27
Ar entina 2,515 25.7 449 125 0.55 9 202 6
Australia 90 10.4 294 82 0.90 0 60
Austria 210 2553 1,609 447 0.20 17
Bel ium 58 3.9 107 30 0.87
Bul aria 1,690 107.2 L637 455 0.48 85 0.13
Canada 377.6 1,023 284 0.09
Caribbean Islands O.l l 0 0.62 0 0 0.3
Chile 0.4 7 2 0.55
China 12,677 2,814.0 31,403 8.724 0.35
Columbia 222 13.3 266 74 0.63 68 6.15
Croatia 927 113.9 555 154 O.IS 1 91 1.9
Czech Re ublic 12.5 ]28 36 0.33 106 0.3
Denmark 44 7.4 75 21 0.32
Finland 80.5 484 134 0.19
France 2,793 326.0 4,895 1,360 0.48 I
Geor is 894 250.0 6,307 1,752 0.80
German 371 397.0 1,568 436 O.13 16
Greece 258 57.1 385 107 0.21 75 200
Guatemala 3.4 107 30 1.00 1 10
Honduras 12 0.7 17 5 0.76 14
Hun a 677 328.3 2,825 785 0.27 4 20 0.5
Iceland 7,619 1,469.0 20,170 5,603 0.44 241 250 90
India 316 80.0 2,517 699 1.00 73 14
Indonesia 73 43 12 0.19
Israel 1,672 63.3 1.713 476 0.86
1[al 1,656 325.8 3,774 1,048 0.37 1 50 10
Ja an 1,670 257.5 5,836 1,621 0.72
Jordan 574 153.3 1,540 428 0.32
Ken a l.3 10 3 0.25
Korea 1,054 51.0 1,077 299 0.67 164 42 276
Lithuania 13 21.0 599 166 Q90 6 102 23.94
Macedonia 761 81.2 510 142 0.20 l 55 15
Mexico 4,367 164.2 3,919 1,089 0.76 0 20 0
Ne al 25 LI 22 6 0.66 8 0.007
Netherlands 10.8 57 16 0.17
New Zealand 132 307.9 7,081 1,967 0.73 1 200 50
Norwa 6.0 32 9 0.17
Peru 2.4 49 14 0.65
Phili Ines 1.0 25 7 0.79
Poland 242 68.5 275 76 Q l3 166 12
Portu aI 49 5.5 35 10 0.20 7
Romania 890 152.4 2,871 797 0.60 14 181 ''-4
Russia 1,466 307.0 6,132 1.703 0.63 306 1043
Serbia 827 80.0 2,375 660 0.94 5 23
Slovak Re ublic 623 132.3 2,118 588 O.SI 4 95 I1.7S
Slovenia 656 42.0 705 196 0.53 IS 43 16A8
Sweden 455 377.0 4,128 ],147 0.35
Switzerland 120 547.3 2,386 663 0.14 4 58 230
Thailand 0.7 15 4 0.6R
Tunisia 19.7 174 4R 0.28
Turke 700 820.0 15,756 4,377 0.61 15 120 25
United Kin dom 25 2.9 2l 6 023
United States 4,550 5,366.0 20,302 5,640 0.12 44 10 42
Venezuela 0.7 14 4 0.63
GRAND TOTAL .54 416 16 210.7 162 009 45 006 0.32 1028 3363 R41
The Lindal diagram (Gudmundsson er ol., skin disease, diseases of the nervous system, ulcers and
1985), named for Baldur Lindal, the Icelandic engineer generally for recuperation aftersurgery. In Rotorua, New
who fist proposed it, indicates the temperature range Zealand at the center of the Taupo Volcanic Zone of
suitable for various direct use activities (Fig. 3). North Island, the Queen Elizabeth Hospital was built
Typically, the agri-cultural and aquacultural uses require during World War II for U.S. servicemen and later be-
the lowest tempera-tures, with values from 25° to 90°C. came the national hospital for the treatment of rheumatic
The amounts and types of chemicals such as arsenic and disease. The hospital has 200 beds, and outpatient
dissolved gases such as boron, are a major problem with service, and a cerebra] palsy unit. Both acidic and baste
plants and animals; thus, heat exchangers are often heated mud baths treat rheumatic diseases.
necessary. Space heating requires temperatures in the In Beppu on the southern island of Kyushu,
range of 50° to 100°C, with 40°C useful in some marginal Japan, the hot water and steam meet many needs:
cases and ground-source heat pumps extending the range heating, bathing, cooking, industrial operations,
down to 4°C. Cooling and industrial processing agriculture re-search, physical therapy, recreational
normally require temperatures over 100°C. The bathing, and even a small zoo (Taguchi er al., 1996).
leading user of geother-mal energy, in terms of market The waters are promoted for "digestive system troubles,
penetration, is Iceland, where more than 86% of the nervous troubles, and skin troubles." Many sick and
population enjoys geo-thermal heat in their homes crippled people come to Beppu for rehabilitation and
from 26 municipal district heating services, and 50% of physical therapy. There are also eight Jigokus ("burning
the country's total energy use is supplied by direct heat hells") in town showing various geothermal phenomena,
and electrical energy derived from geothermal resotuces used as tourist attractions.
(Ragnarsson, 2000). Tn the former Czechoslovakia, the use of
thermal waters has been traced back before the
°F~ occupation of the Romans and has had a recorded use of
almost 1,000 years. Today, [here are 60 spa resorts
, "_~+_°'~°^'r^^^^°^~^_"^°'^^^ located mainly in Slovakia, visited by 460,000 patients
DiNOU^nm P+M P°IP CONC[NTIONAL
~,,,P°,,,,„mo, eLrc-rx~~~ usually for an average of three weeks each. These spas
ciNeaATION have old and well-established therapeutic traditions.
8 IW Alwn~~u.in Beyc~'z puce
L.tlP°IBII^111115^gN r=fininp I:LkCTllt
eevennroND Owaters atnd s tine cas ava labilrt oof t eat and sulfu orus
D^~^+v,e=^^^d^'==m=^~^„x' mud, and climatic conditions, each sanitarium is
I W Dm^s m ^e^=wlu<ei a^.v^..,
°ry,^"°,,,°„E,„ designated for the treatment of specific diseases. The
"P><'=„=~^^.I~,~<~^" ".=m„^~•~ therapeutic successes of these spas are based on centuries
Is° c°m ,.°,.P`
of healing tradition (balneology), systematically
A,,.°^e,..^^~~~P
,ma„,.,",^e, ~ supplemented by the latest discoveries of modem medical
1°0 6oi1 sPUL xeaTwc SCIeRCe (LLLnd, 1990).
5^immi
{~p°I,. ale-look °ITH HI'AT PLNPS
FD„,,,,,,~" Bathing and therapeutic sites in the U.S.
° included: Saratoga Springs, New York; Warm Springs,
Georgia; Hot Springs, Virginia; White Sulfur Springs,
West Virginia; Hot Spring, Arkansas; Thermopolis,
Figure 3. Lindal diagram. Wyoming and Calistoga, California. The original use of
these sites were by Indians, where they bathed and
Swimming, Bathing and Balneology recuperated from battle. There are over I IS major
geothermal spas in the U.S. with an annual energy use of
Romans, Chinese, Ottomans, Japanese and 1,500 TJ (Lund, 1996b).
central Europeans have bathed in geothemral waters for
centuries. Today, more than 2,200 hot springs resorts in Space Conditioning
Japan draw 100 million guests every year, and the
"return-to-nature" movement in the U.S. has revitalized Space conditioning includes both heating and
many hot spring resorts. cooling. Space heating with geothermal energy has
widespread application, especially on an individual basis.
The geothermal water at Xiaotangshan Buildings heated from individual wells are popular in
Sanitarium, northwest of Beijing, China, has been used Klamath Falls, Oregon: Reno, Nevada, and Taupo and
for medical purposes for over 500 }ears. Today, the 50°C Rotorua, New Zealand. Absorption space cooling with
water is used to treat high blood pressure. rheumatism, geothermal energy has not been popular because of the
high temperature requirements and low efficiency. heat. A geothermal well field is the primary source of
Geothermal heat pumps (groundwater and ground- heat; however, depending on the temperature, the district
coupled) have become popular in the U.S. and may be a hybrid system, which would include fossil fuel
Switzerland, used for both heating and cooling. and/or heat pump peaking.
An example of space heating and cooling with Geothermal district heating systems are in
low-to-moderate temperature geothermal energy is the operation in at least 12 countries, including Iceland,
Oregon Institute of Technology in Klamath Falls, Oregon France, Poland, Hungary, Turkey, Japan and the U.S. The
(Figure 4). Here, eleven buildings (approximately Warm Springs Avenue project in Boise, Idaho, dating
62,000 sq. m of floor space) are heated with water from back to 1892 and originally heating more than 400 homes.
three wells at 89°C. Up to 62 Us of fluid can be provided is the earliest formal project in the U.S. The Reykjavik,
to the campus, with the average heat utilization rate over Iceland, district heating system (Figure S) is probably the
O.S3 MWt and the peak at S.6 MWt. In addition, a S41 most famous (Frimannsson 1991 and Lund, 1996a). This
kW (l S4 tons) chiller requiring up to 38 L/s of system supplies heat for a population of around 160,000
geothermal fluid produces 23 L/s of chilled fluid at 7°C people. The installed capacity of 830 MWt is designed to
to meet the campus cooling base load (recently decom- meet the heating load to about -10°C; however, during
missioned)(Boyd, ]999). colder periods, the increased load is met by large storage
tanks and an oil-fired booster station (Ragnazsson, 2000).
District Heating In France, production wel Is in sedimentary basins
provide direct heat to more than 500,000 people from 6I
District heating originates from a central projects. These wells provide from 40 to 100°C water
location, and supplies hot water or steam through a from depths of 1,500 to 2,000 m. In the Paris basin, a
network of pipes to individual dwellings or blocks of doublet system (one production and one injection well)
buildings. The heat is used for space heating and provides 70°C water, with the peak load met by heat
cooling, domestic water heating and industrial process pumps and conventional fossil fuel burners (Figure 6).
Natural
Storage Convection
Took
15 m'
Three Wells 89°C Domestic 79"C 5"'C
6' Us of Water Q~
60"C
8R°C 57°C Forced Air
Downhole Com~ecfion
Pumps
Well Depth Other Shell-and-Tube
400-550 m Buildings Heat Exchanger Plate Heal
Exchanger
34"C Condenser 88"C RS°C 52°C
'~"C
Forced
Air 73.,C.
Cooling
Tower
7C Q~
~y~~C I,"C
Forced Air
Corn ection
Figure 4. Oregon Institute of Technology heating and cooling system.
~ Vent
89°D ~
89°C Peaking Station
~ Storage Tanks T~~
Pumping
Station
T~
rj Lineshaft 96°C I
ri Pumps ~
I
Vent ~ ~ Heating
Ellidaar Field Lineshaft
180 kg/s Pumps I ~ ~ W
125°C 1 5°C ( 80°C 35°C~
Mixing Heating
~
Laugarnes Field Lineshaft Drains
290 kg/s Pumps
Figure 5. Reykjavik district heating system (prior to the Nesjavellir connection).
11I- - - - ~ - Agribusiness Applications
'li` ~ m 9 $ Agribusiness applications (agriculture and
g`~ ii ~ a ~i ~ ~ aquaculture) are particularly attractive because they
require heating at the lower end of the temperature range
~ ! Space Heating a where there is an abundance of geothermal resources.
70-80 m'/h Use of waste heat or the cascading of geothermal energy
65°C_L__-r~ also has excellent possibilities. Anumberofagribusiness
tr ti:~ applications can be considered: greenhouse heating,
70°C 35°C aquaculture and animal husbandry, soil warming and
Heat Exchangers irrigation, mushroom culture, and bio-gas generation.
~ I ~ Numerous commercially marketable crops have
~/~/~.-'~-~65°C ~ been raised in geothermally heated green-houses in
~~"""`~~rt Hungary, Russia, New Zealand, Japan, Iceland, China
Domestic Water ~ and the U.S. These include vegetables , such as cucum-
20-30 m'/h bets and tomatoes, flowers (both potted and bedded),
~ houseplants, tree seedlings, and cacti. Using geothermal
~ energy for heating reduces operating costs (which can
account for 35% of the product cost) and allows
Production Reinjection ~ operation m colder climates where commercial
95 m'/h greenhouses would not normally be economical.
The use of geothermal energy for raising catfish,
shrimp, tilapia, eels, and tropical fish has produced crops
faster than by convcmional solar heating. Using geother-
Figure6. Melun 1'Almont (Paris)doublet mal heat allows better control of pond temperatures,thus
heating system. optimizing growth (Figure 7). Fish breeding has been
successful in Japan, China and the U.S. A very
successful prawn raising operation, producing 400 tons
of Giant Malaysian Freshwater Prawns per year at US$ production has been attempted in the U.S.; however, the
17 to 27ikg has been developed near the Wairakei economics were marginal and thus this industry has not
geothermal field in New Zealand (Lund and Klein 1995). been successful.
The most important factors to consider are the quality of Drying and dehydration are important
the water and disease. If geothemtal water is used moderate-temperature uses of geothermal energy.
directly, concentrations of dissolved heavy metals, Various vege-table and fruit products are feasible with
flurorides, chlorides, arsenic, and boron must be continuous belt conveyors (Figure 8) or batch (truck)
considered. dryers with air temperatures from 40° to 100°C (Lund
and Rangel 1995). Geothermally drying alfalfa, onions,
Temperature 'F pears, apples and seaweed are examples of this type of
3z so 68 ea to direct use. Anew development in the use of
roo ON5 0hi1cens geothermal fluids is the enhanced heap leaching of
precious metals in Nevada by applying heat to the
eo cyanide process (Trexlerer al. 1990). Using geothermal
.I°~~ energy increases the efficiency of the process and extends
E the production into the winter months.
60
6
p Shnm Calfis
a0 ~ Crr c.w.n ~~n,r n.rw
c \ ~
!i / II III V~wAY
a° zo t
..r
~,s
0 ' ~ It, orrri
0 10 20 30 d0 qye °iti
Temperature °C
Figure 8. Continuous belt dehydration plant,
Figure 7. Effect of temperature on animal and schematic.
fish growth.
EQUIPMENT
Livestock raising facilities can encourage the
growth of domestic animals by a controlled heating and Standard equipment is used in most direct-use
cooling environment. An indoor facility can lower projects, provided allowances are made for the nature of
mortality rate of newborn, enhance growth rates, control geothermal water and steam. Temperature is an
diseases, increase litter size, make waste management important consideration, so is water quality. Corrosion
and collection easier, and in most eases improved the and scaling caused by the sometimes unique chemistry of
quality of the product. Geotherrnal fluids can also be geothermal fluids, may lead to operating problems with
used for cleaning, sanitizing and drying of animal equipment components exposed to flowing water and
shelters and waste, as well as assisting in the production steam. In many instances, fluid problems can be
of bio-gas from the waste. designed out of the system. One such example concerns
dissolved oxygen, which is absent in most geothermal
Industrial Applications waters, except perhaps the lowest temperature waters.
Care should be taken to prevent atmospheric oxygen
Although the Lindal diagram shows many from entering district heating waters; for example, by
potential industrial and process applications of proper design of storage tanks. The isolation of
geothermal energy, the world's uses are relatively few, geothermal water by installing a heat cxchangermay also
The oldest industrial use is at Larderello, Italy, where solve this and similar water quality derived problems. In
boric acid and other borate compounds have been this case, a clean secondary fluid is then circulated
extracted from geothermal brines since 1790. Today, the through [he used side of the system as shown in Figure 9.
two largest industrial uses aze the diatomaceous earth The primary components of most low-
drying plant m northem Iceland and a pulp, paper and temperature direct-uscsystemsaredownholcandcircula-
wood processing plant at Kaweraq New Zealand. tion pumps, transmission and distribution pipelines,
Notable U.S. examples arc two onion dehydration plants peaking or back-up plants, and various forms of heat
in northem Nevada (Lund 1995), and a sewage digestion extraction equipment (Figure 9). Fluid disposal is either
facility in San Bernardino, California. Alcohol fuel
ss•c produced for district heating. Detailed discussion of
equipment desigm and use can be found in Lund et ul.
(1998).
.uTE RE, T
EXLMANGER
ENE0.GV Downhole Pumps
V8E0.
BYHTEM
rs•c Unless the well is artesian, downhole pumps are
needed, especially in large-scale direct utilization system.
Downhole pumps may be installed not only to lift fluid to
eo°c so°c the surface, but also to prevent the release of gas and the
PEA0.IMG
R"°°°=T'°" 'ReE=r°" E•="~°• resultant scale formation. The two most common types
weuREA° wEUREAG a"n
E°"'RMERT E°NPME"' are: lineshaft pump systems and submersible pump
i systems.
1 The lineshafr pump system (Figure 10) consists
of a multi-stage downhole centrifugal pump, a surface
Figure 9. Geo[hcrmaldircct-utilization system mounted motor and a long driveshaft assembly extending
using a heat exchanger. from the motor to the pump. :lost arc enclosed, with the
shafr rotating within a lubrication column which is
surface or subsurface (injection). A peaking system may centered in the production tubing. This assembly allow
be necessary to meet maximum load. This can be done the bearings to be lubricated by oil, as hot water may not
by increasing the water temperature or by providing tank provide adequate lubrication. A variable-speed drive set
storage (such as done in most of the Icelandic district just below the motor on the surface, can be used to
heating systems). Both options mean that fewer wells regulate flow instead ofjust fuming the pump on and off.
need to be drilled. When the geothermal water tempera- The electric submersible pump system (Figure
tore is wamr (below 50°C), heat pumps are often used. l 1) consists of a multi-stage downhole centrifugal pump,
The equipment used in direct-use projects represent a downhole motor, a seal section (also called a protector)
several units of operations. The major units will nov< be between the pump and motor, and electric cable extending
described in the same order as secs by geothermal waters from the motor to the surface electricity supply.
~~,.".N
PumV Caym~
My'n waunaaa
5 ee0ap',Nive coupling
wannaae comm.
Main Elen~e'
NN Lon cola Cdumn 6pamr Caec4 Le[le
Bez ing ILen121ixe,1 Velve
G•lumr•~Spattr
SncN De~ai:
Well
piawin g
9a Oyen L~Mrna Camn
_ Beanng LUM Cai on
ProCUClion Muf umy 9a
Tueinq pizr ne9a
rP~my cm~m~~ ~,aaa ~~~a,nen
Enmosing r°ea
P~
Mu1,r5tage µe11 laiaxe
PumV Lasing
g R~o ec[ ian
hake ~ Pump Cdumn , n
Pome.e
saa
Pumy Loiumn SVacar
Cleilr.
Mo,w
Entlose4 LmesNall
5ear~nq LUer~relin~
Figure 10. Lineshaft pump. Figure 11. Submersible pump.
Both types of downhole pumps have been used over U.S.$300 per meter of length), tunnels and trenches
for many years for cold water pumping and more recently have the advantage of easing future expansion, providing
in geothermal wells (lineshafts have been used on the access for maintenance and a corridor for other utilities
OregonInstiruteofTechnologycampusin89°C water for such as domestic water, waste water, electrical cables,
45 years). If a lineshaft pump is used, special allowances phone lines, etc.
must be made for the thermal expansion of vazious Supply and distribution systems can consist of
components and for oil lubrication of the bearings. The either asingle-pipe or atwo-pipe system. The single-pipe
lineshaft pumps are preferred over the submersible pump is aonce-through system where the fluid is disposed of
in conventional geothermal applications for two main after use. This distribution system is generally preferred
reasons: the lineshafr pump cost less, and it has a proven when the geothermal energy is abundant and the water is
track record. However, for setting depths exceeding pure enough to be circulated through the distribution
about 250 m, a submersible pump is required. system. In a two-pipe system, the fluid is recirculated so
the tuid and residual heat are conserved. A two-pipe
Piping system must be used when mixing of spent fluids is called
for, and when the spent cold fluids need to be injected into
The fluid state in transmission lines of direct- the reservoir Two-pipe distribution systems cost typically
use projects can be liquid water, steam vapor or a two- 20 to 30 percent more than single-piped systems.
phase mixture. These pipelines carry fluids from the The quantity of thermal insulation of
wellhead to either a site of application, or a steam-water transmission lines and distribution networks will depend
separator. Thcrmalexpansionofpipelinesheatedrapidly on many factors. In addition to minimize the heat loss of
from ambient to geothermal fluid temperatures (which the Fluid, [he insulation must be waterproof and water
could vary from 50 to 200°C) causes stress that must be tight. Moisture can destroy the value of any thermal
accommodated by careful engineering design. insulation, and cause rapid extemal corrosion.
The cost of transmtssion Tines and the Aboveground and overhead pipeline installations can be
distribution networks indirect-use projects is significant. considered in special cases. Considerable insulation is
This is especially true when the geothermal resource is achieved by burying hot water pipelines. For example,
located at great distance from the mam load center; burying bare steel pipe results in a reduction in heat loss
however, transmission distances of up to 60 km have of about one-third as compared to aboveground in still air.
proven economical for hot water (i.e., the Akranes If the soil around the buried pipe can be kept dry, then the
project in Iceland-Ragnarsson & Hrolfsson, 1998),where insulation value can be retained. Carbon steel piping can
asbestos cement covered with earth has been successful be insulated with polyurethane foam, rock wool or
(sec Figure 13 later). fiberglass. Below ground, such pipes should be protected
Carbon steel is now the most widely used with polyvinyl chloride (PVC) jacket; aboveground,
material for geothermal transmission lines and aluminum can be used. Generally, 2.5 to 10 cm of
distribution networks; especially if the fluid temperature insulation is adequate. In two-pipe systems, the supply
is over 100°C. Other common types of piping material and return lines are usually insulated; whereas, in single-
are fiberglass reinforced plastic (FRPI and asbestos pipe systems, only the supply line is insulated.
cement (AC). 'ihe latter matenal, used widely in the At flowing conditions, the temperature loss in
past, cannot be used in many systems today due to insulated pipelines is in the range of 0.1 to I.0°C/km, and
environmental concerns; thus, it is no longer available in in uninsulated lines, the loss is 2 to 5°C/km (in the
many locations. Polyvinyl chloride (PVCI piping is often approximate range of 5 to 15 L/s flow for 1 ~-em diameter
used for the distribution network, and for uninsulated pipe)(Ryan 1981). It is less for larger diameter pipes (i.c.,
waste disposal lines where temperatures are well below Icss than 2°C loss is experienced in the new aboveground
100°C. Conventional steel piping requires expansion 29 km long and 80 and 90 em diameter line (with 10 cm
provisions, either bellows arzangements or by loops. A of rock wool insulation) from Nesjavcllir to Reykjavik in
typical piping installation would have fixed points and Iceland. The flow rate is around 560 L/s and takes seven
expansion points about every 100 m. In addition, the hours to cover the distance. Unnnsulated pipe costs about
piping would have to be placed on rollers or slip plates hallbf insulated pipe, and thus, is used where temperature
between points. When hot water pipelines are buried, loss is not critical. Pipe material does not have a
they can be subjected to external corrosion from significant effect on heat loss; however, the Flow rate
groundwater and electrolysis. They must be protected by does. At low flow rates (off peak), the heat loss is higher
coatings and wrappings. Concrete runnels or trenches than as greater flows. Figure 12 shows fluid temperatures,
have been used to protect steel pipes in many geothermal as a function of distance, in a 45-em diameter pipeline,
district heating systems. Although expensive (generally insulated with 50 cm of urethane.
~'°'"'""'°"'°'v'""""°° Heat Exchangers
15 ]C 15 8° i5
z° The principal heat exchangers used in
geothermal systems are the plate, shell-and-tube, and
v ° u° downhole types. The plate heat exchanger consists of a
series of plates with gaskets held in a frame by clamping
5° 'a° ~ rods (Figure 14). The counter-current flow and high
turbulence achieved in plate heat exchangers, provide for
~ ~ ~ - - _ _ ' ~ _ - _ ~ efficient thermal exchange in a small volume. In addition,
- - - 51VZ ~ _ - ~ - - - _ they have [he advantage when compared toshell-and-tube
16B/5 X05 MS) ID°
exchangers, of occupying less space, can easily be
s°" expanded when addition load is added, and cost 40%
6°
° less. The plates are usually made of stainless steel;
" althou h, titanium is used when the fluids are
irinsmissunlengi"-km g
especially corrosive. Plate heat exchangers are commonly
Figure 12. Temperature drop in hot water used in geothermal heating situations worldwide.
transmission line.
Several examples of aboveground and buried
pipeline installations are shown in Figure 13.
Steel piping is shown in most case, but FRP or
PVC can be used in low-temperature applications. ~
Aboveground pipelines have been used extensively in
Iceland, where excavation in lava rock is expensive and Ji ~ ~ ~
difficult, however, in the USA, below ground
installations are more common to protect the line from
vandalism and to eliminate traffic barriers. A detailed
discussion of these various installations can be found in
Gudmundsson and Lund (1985). Figure 14. Plate heat exchanger.
-rt- -
P~...w. s
o~~.~m
I
~ ~o,~
" ae
a bj
sat
m uyn
E.nn
~ d)
Figure 13. Examples of above and below ground pipelines: a) aboveground pipeline with sheet metal cover,
b) steel pipe in concrete tunnels, c) steel pipe with polyurethane insulation and polyethylene
cover and d) asbestos cement pipe with earth and grass cover.
Shell-and-tube heat exchangers may be used for (Kavanaugh and Rafferty 1997; Rybach and Sanner,
geothermal applications, but are less popular due to 2000). Groundwater aquifers and soil temperatures in
problems with fouling, greater approach temperature the range of 5 to 30°C are being used in these systems.
(difference between incoming and outgoing fluid Ground-source heat pumps (GSHP) utilize groundwater
temperature), and [he larger size. in wells or by direct ground coupling with vertical heat
Downhole heat exchangers eliminate the exchangers (Figure 16). Just about every state in the
problem of disposal of geothermal fluid, since only heat USA, especially in the mid-western and eastern states are
is taken from the well. However, their use is limited to utilizing these systems in part subsidized by public and
small heating loads such as the heating of individual private utilities. It is estimated that almost 60,000
homes, a small apartment house or business. The groundwater systems, and more than 184.000 closed-loop
exchanger consists of a system of pipes or tubes vertical and 152,000 horizontal systems arc already in
suspended in the well through which secondary water is use.
pumped or allowed to circulate by natural convection
(Figure 15). In order to obtain maximum output, the
well must be designed to have an open annulus between
the wellbore and casing, and perforations above and
below the heat exchanger surface. Natural convection ? ?
circulates the water down inside the casing, through the o _
lower perforations, up in the annulus and back inside the
casing through the upper perforations (Culver and
Reistad 1978; GHC Quarterly Bulletiq Vol. 2Q No. 3,
1999). The use of a separate pipe or promoter, has
proven successful in older wells in New Zealand to
increase the vertical circulation (Dunstall and Freeston
1990).
s~q° u"F
co"
rna,m".~i
sole"om .a«
Figure 16. Typical ground-source heat pump
installation.
~.~..K cry
..~e,
~m°
Wei^~~ Like refrigerators, heat pumps operate on the
c""°"'°'°°' basic principle that fluid absorbs heat when it evaporates
cae~~
w°~° ~ into a gas, and likewise gives off heat when it
P,n",a„o"~ condenses back into a liquid. A geothermal heat pump
system can be used for both heating and cooling. The
''P""a's""~ types of heat pumps that are adaptable to geothermal
ooe",",", energy are the water-to-air and the water-to-water. Heat
pumps are available with heating capacities of less than
~~^'~"~o=«=m~ 3 kW to over L500 kW.
oeno,e~~o".
- _ _ ~,a,"p,m Convectors
°a~
Heating of individual rooms and buildings is
Figure 15. Downhole heat exchanger (typical of achieved by passing geothermal water (or a heated
Klamath Falls, Oregon). secondary Fluid) through heat convectors (or emitters)
located in each room. The method is similar to that used
Heat Pumps in conventional space heating systems. Three major
types of heat convectors are used for space heating: 1)
At the present time, ground-coupled and forced air, 2) natural air flow using hot water or finned
groundwater (often called ground-source or geothermal) tube radiators, and 3) radiant panels (Figure 17). All
heat pump systems are being installed in great numbers these can be a dapted directly to geothermal energy or
in the United States, Switzerland and Germany converted by retrofitting existing systems.
Hot Water the freezing point of water. The major application of
lithium bromide units is for the supply of chilled water
for space and process cooling. They may be either one-
I ~ or two-stage units. The two-stage units require higher
Air ~ ~ Wartn Air temperatures (about 160°C); but, they also have high
I efficiency. The single-stage units can be driven with hot
water at temperatures as low as 77°C (such as at Oregon
Institute of Technology -see Figure 4). The lower the
Wa j Water temperature of the geothermal water, the higher the flow
a rate required and the lower the efficiency. Generally, a
condensing (cooling) tower is required, which will add to
Warm Air t Hot Water the cost and space requirements.
t r Forgeothermally-drivenrefrigerationbelowthe
~ freezing point of water, the ammonia absorption system
must be considered. However, these systems are
1 normally applied in very large capacities and have seen
~ limited use. For the lower temperature refrigeration, the
Warm Water ~ Air driving temperature must be at or above about 120°C for
b) a reasonable performance. Figure 18 illustrates how the
geothermal absorption process works.
~ Warm Air
IN Cooling OUT IN GeWafer a OUT
Water
c°°x~.., c.°«.,«
~ ~ O O 0 Hot Water
- ~
Warts Wataf liquitl Ammonia
Weak Ammonia-
Water Solution
Air
Eapanai°n VeHe
C
p Eve~n,or Cml
~ ! ~ ~ ~ S ~ ~ Ammonia
\ \ ~ ~ \ ~ Pump
~ ~ ~ ~ HOt Watef noon.,
a.mq«a.° Cooling
sp.ce OUT Water IN
Warm Water
d~ Figure l8. Geothermalabsorptionrefrigeration
c_vclc.
Figure 17. Convectors: a) forced air, b) material
convection (finned tube), c) natural ECONObffC CONSIDERATIONS
convection (radiator), and d) floor
panel. Geothermal projects require a relatively large
initial capital investment, with small annual operating
costs thereafter. Thus, a district heating project,
Refrigeration including production wells, pipelines, heat exchangers,
and injection wells, may cost several million dollars. IIy
Cooling cam be accomplished from geothermal contrast, the initial investment in a fossil fuel system
energy using lithium bromide and ammonia absorption includes only the cost of a central boiler and distribution
refrigeration systems (Raffeny, 1983). The lithium lines. The annual operation and maintenance costs for
bromide system is the most common because if uses water the two systems are similar, except that the fossil fuel
us the refrigerant However, it is limited to cooling above system may continue to pay for fuel at an every-
inereasing rate; while, the cos[ of [he geothermal fuel is
stable. The two systems, one with a high initial capital with a range from US$ 40 to US$ 1880/kW. In the U.S.,
cost and the other with high annual costs, must be the annual operation and maintenance cost is estimated
compared. at 5% of the installed cost.
Geothermal resources fill many needs: power
generation, space heating, greenhouse heating, industrial FUTURE DEVELOPMENTS
processing, and bathing to name a few. Considered
individually, however, some of the uses may not promise There appears to be a large potential for the
an attractive return on investment because of the high development of low-to-moderate enthalpy geother-mal
initial capital cost. Thus, we may have to consider using direct use across the world which is not curtently being
a geothermal fluid several times to maximize benefits. exploited due to financial constraints and the low price
This multistage utilization, where lower and lower water of competing energy sources. Given the right
temperatures are used in successive steps, is called environment, and as gas and oil supplies dwindles, the
cascading or waste heat utilization. A simple form of use of geothermal energy will provide a competitive,
cascading employs waste heat from a power plant for viable and economic alternative source of renewable
direct use projects (Figure 19). energy.
Future developmentwill most likely occur under
the following conditions:
r' Z
Food Processing tw~c Apatlmenl I. Collocated resource and uses (within !0 km
~ Builtling
apart),
2. Sites with high heat and cooling load density
(>36 MWUsq.km).
Retdgeraonn c~eennn"ae ~ 3. Food and grain dehydration (especially in
plain tropical countries where spoilage is common),
4. Greenhouses in colder climates,
r S. Aquaculture to optimize growth--even in warm
y F,anFatm climates, and
2°0~0 R 6. Ground-coupled and groundwater heat pump
POwef aia°~ installation (both for heating and cooling).
1
REFERENCF,S
Figure 19. An example of cascading. Boyd, T. L., 1999. The Oregon Institute of Technology
Geothermal Heating System -Then and Now,
Geothermal cascading has been proposed and Geo-Heat Center QuarterA~ &dletin, Vol. 2Q,
successfully attempted on a limited scale throughout the No. I, Klamath Falls, OR, pp. 10-13.
world. In Kotoma, New Zealand, for example, after
geothermal water and steam heat a home, the owner will Culver, G. G. and G. M. Reistad, 1978. Evaluation and
often use the waste heat for a backyard swimming pool Design of Downhole Heat Exchangers for
and steam cooker. At the Otake geothermal power plant Direct Applications, Geo-Heat Center, Klamath
in Japan, about 165 tonnes per hour of hot water flows to Falls, OR.
downstream communities for space heating, greenhouses,
baths and cooking. In Sapporo, Hokkaido, Japan, the Dunstall, M. G. and D. M. Frecston, 1990. U-Tube
waste water from the pavement snow melting system is Downhole Heat Exchanger Performance in a 4-
retained at 6~°C and reused for bathing, in. Well, Rotoma, New Zealand, Proceedings of
Recent estimates (1990 data) of the capital cost the !2'" New' Zealand Geothermal Workshop:
for various direct use projects in the U.S. arc as follows: 229-232.
Frecson, D. H., 1996. Direct Uses of Geothermal
Space hcating pndividual): US$463ikW oflnstallcd capacty EnCrgy 199$, Ge0therm(CS, ZS(2): 189-214.
D~strfct hcating: US$ 386/kW oflnstallcd capacty
Greenhouses. US$ 1?O~k\4 oflnstallcd capacity
Aquaca~n~re. us5 ?6m.W oflm~aued eapaaty Frimannsson, H., 1991. Hitaveita Reykjavikur After 60
Years ofOperation -Development and Benefits,
Recent international data (Frecston, 1996) gives Geo-Heat Center Quarterli~ Bulletin, Vo.
US$ 270/kW of installed capacity for all projects reported, 13(4).: 1-7.
Geo-Heat Center, 1997. Quorterl}~ Bulletin, 19(1), Lund, J. W.; Lienau, P. J. and B. C. Lunis (editors),
Geothermal Direct-Use Equipment: 38 p. 1998. Geothermal Direct-Use Engineering and
Design Guidebook, Geo-Heat Center, Klamath
Geo-Heat Center, 1999. Downhole Heat Exchangers, Falls. OR: 470 p.
Gm-Heat Center Quarterly Bulletin, Vol. 2Q
No. 3 (September Klamath Falls, OR, 28 p. Lund, J. W. and T. L. Boyd, 2000. Geothermal Direct-
Use in the United States, Update: 1995 - 1999,
Gudmundsson, J. S.; Freeston, D. H. and P. J. Lienau, ProceedingsofrheWorldGeodrermalCongresc
1985. The Lindal Diagram, Geothermal 200, Japan
Resources Camcil Transaction, 9(1): 15-19.
Lund, J. W. and D. H. Freeston, 2000. Worldwide
Gudmundsson, J. S. and J. W. Lund 1985. Direct Uses of Direct Uses of Geothemtal Energy 2000,
Earth Heat, Energi~ Research, 9: 345-375. Proceedings ojthe World Geothermal Congress
2000, Japan.
Kavanaugh, S. and IC Rafferty, 1997. Ground-Source
Design of Geothemtal Systems for Commercial Muffler, L. P. J., editor, 1979. Assessment of
and Institutional Buildings, ASHRAE, Atlanta, Geothermal Resources of the United States -
G.A: 167 p. 1978, USGS Circular 790, Arlington, VA.
Lienau, P. J.; Lund, W. and G. Gene Culver, 1995. Rafferty, K., 1983. Absorption Refrigeration: Cooling
Geothermal Direct Use in the United States, with Hot Water, Geo-Heat Center Quarta~lr
Update: 1990-1994, Proc. World Geothermal Bulletrn, Vol. 8(1): I7-?0.
Congress 1995: 363-372.
Ragnarsson, A., 2000. Iceland Country Update, Proc. of
Lund. J. W., 1990. Geothermal Spas in Czechoslovakia, the LG-or/d Geothermul Congress 2000, Japan .
Geo-Heat Center Quarrer/J~ Bulletin, 12(2): 20-
24. Ragnarsson, A. and L Hrolfsson, 1998. Akranes and
Borgarfjordur District Heating Sysrem, Geo-
Lund, J. W., 1995. Onion Dehydration, Geothermal Heat Center Quarterlr Bulletin, Vol. 19, No. 4
Resources Cnanci( Prmzsaction. 19: 69-74. (December), Klamath Falls, OR, pp_ 10-13.
Lund, J. W. and R. Klein, 1995. Prawn Park - Taupo, Ryan, G. P., 198i. Equipment Used in Direct Hcat
New Zealand, Geo-Heat Center Quarterlr Projects, Geothermal Resources Council
Bulletin, 16(4): 27-29. Transrretionr, 5: 483-485.
Lund, J. W. and M. A. Rangcl, 1995. Pilot Fruit Drier for Rybach. L. and B. Sanner, 2000. Ground-Source Hca[
the Los Azu fres Geothermal Field, Mexico, Proc. Pump Systems -The European Experience,
of the World Geothemtal Congress 1995: 2335- Geo-Neat Center Quarterh~ Bulletin, Vol. _I,
2338. No. 1 (March), Klamath Falls, OR, pp. 16-26.
Lund, J. W., 1996a. Hitaveita Reykjavikur and the Taguchi, S.; Itoi, R. and Y. Ysa, 1996. Beppu Hot
Ncsjavcllir Geothemtal Co-Generation Power Springs, Geo-Heat Center Quarterlr' Bulletin,
Plan[,Geo-Heat Center Quarterh~Bu/latin, Vol. (17(2 I-6.
17(4): 7-13.
Trcxler, D. T.; Flynn, T. and J. W. Hendrix, 1990. Heat
Lund, J. W., 1996b. Balneological Use of Thermal and Leaching,Geo-Hear Center Quarterly Bulletin,
:Mineral Waters in the USA, Geothermies, 25(I): 12(4): 1-4.
103-148.