· \

Geothermic:s, Vol. 15, No. I, pp. 133-142,1986.Printed in Great Britain.

0375 - 6505/86 $3.00 + 0.00Pergamon Press Lid.

© 1986 CNR.

THE HAWAII GEOTHERMAL APPLICATIONS PROGRAM

P. TAKAHASHI,* A. SEKI* and B. CHENt

·University of Hawaii at Manoa, 2540 Dole Street, Holmes 246, Honolulu, Hawaii 96822, U.S.A. andtUniversity of Hawaii at Hila, 1400 Kapiolani Street, Hilo, Hawaii 96720, U.S.A.

(Received August 1985)

Abstract-The Puna Research Center (PRC) will provide a facility next 10 the Hawaii GeothermalProject for high technology research, development and demonstration in geothermal and relatedactivities. PRe will initiate an industrial park development and examine multi~purpose dehydration,minerals utilization and biomass applications related to this technology. The facility will becomeoperational in autumn 1985.

INTRODUCTION

The Hawaii Geothermal Project (HGP) began in 1972 when the Hawaii State Legislatureallocated $200,000 to identify and utilize geothermal resources in Hawaii. The initial effort,which was co-funded by the National Science Foundation, began in mid-1973 on the Island ofHawaii 'with the University of Hawaii at Manoa (UHM) and Hilo campuses conductinggeophysical, geochemical, engineering, environmental and socioeconomic programs.

After the researchers identified a well site in the Puna District on the east rift of KilaueaVolcano (Fig. 1), a drilling program was initiated in 1975 with funding from the EnergyResearch and Development AgencY,.State of Hawaii, and County of Hawaii. The HGP-A well.named after the late Agatin T. Abbott, Professor of Geology at UHM, was completed to adepth of 1966 m in April 1976. A bottomhole temperature of approximately 358°C makesHGP-A one of the hottest geothermal wells in the world (Yuen el 01., 1978). Scientists havepredicted that the available energy in the Kilauea East Rift Zone is on the order of about 50,000megawatt-years (438 x lOt kWh).

During 1976 and 1977, Yuen el 01. (1978) conducted several sets of flow tests ..to gather dataon water source and fluid characteristics to make preliminary predictions of the reservoir size,shape and production capacity. Typical temperature and pressure profiles are shown in Figs 2and 3. These measurements were taken with varying production flow rates. The statictemperature is also shown in Fig. 2, where the upper 610 m section is cooling rapidly due to thepresence of the cement casing (now lowered to 914 m). The pressure profile displayed in Fig. 3shows three distinct slopes. One break occurs at the bottom of the casing and the other at asuspected major production lone. The throttled flow tests, as presented in Table I, showed thata 3 MW system was potentially possible for this geothermal well. The limited information aboutthe reservoir was obtained by utilizing standard petroleum engineering techniques with themajor assumption of a single phase flow, although steam and water were emitted from the well.The conclusions of all these tests are presented in Table 2.

In order to o.btain additional information about the geothermal resource, as well as todemonstrate the feasibility of geothermal energy utilization, the HGJ:l-A Wellhead GeneratorFeasibility Project was then proposed. In June 1978, the U.S. Department of Energy (USDOE),State of Hawaii, UHM, the County of Hawaii, and Hawaii Electric Light Company (HELCO)joined forces to design. construct. operate and maintain a geothermal power plant at HGP-A(Chen el 01., 1979).

Construction was completed in June 1981, and after an initial shakedown period, the plant

133

134 P. Takahashi, A. Seki and 8. Chen

!I.!!l IIlte of COllIplltlon

G.othe,.....' 1 1961G.oth.1'1IIl1 2 1961Geoth."..l 3 191~

HGP-~ 1916~.hldl 1 1980I:.lpoho 1 1981Llnlp.nl 1 1981I:.lpoho 2 1982Llnlplln. 6 198~

0 5 10, ! ,KILOMETERS

Fig. I. Map of geothermal locations.

started to generate electricity in early 1982 (Chen et 01., 1979, 1980). Since then, the power planthas been on line 920/0 of the time, generating approximately 2.6 gross MW of electricity. Two­tenths of a megawatt are used in-plant and the remaining power is transmitted to HELCO'selectric grid as the first and only geothermal electricity in Hawaii. In August 1983, the firstscheduled routine maintenance was conducted and the turbine showed very little wear or scalebuildup. The actual maintenance work was finished in half the scheduled time. Geothermalenergy was thus shown to be technically viable in Hawaii. Table 3 summarizes the HGP-Apower plant operation. Table 4 compares HGP-A with Barstow's Solar One power tower.

Thomas (1985a) recently reported an increase in production at the HGP-A powerplant from2.6 to 2.9 gross MW. An analysis of the geothermal fluids has shown no change in the chemical

Hawaii Geolhermal Applicalions Program 135

T.ril~r.lu ... InOC

2000

i1000 ::lE

.et.!

1500

500

8

600500400300200100

0 50 100 150 21 10 250 300 35

"'1\ ~, \

'"~ \ II -. \

ll-l'.:~

\\ \""""~

-l

0

~~ }

II \ t0

t} } ~ "-.4 5 -

0700

o

600

5000

1000

2000

•.% 3000

.el.! 400

Temperalure In of

Fig. 2. Temperature profiles at HGP-A. Steam flow in klb/h (kg/s in parentheses): (I) 64 (8.1), (2) 57 (7.2), (3) 48 (6.1),(4) 39 (4.9), (5) O.

Pressure In Pslg

00 m ~ ~ ~ ~ ~ ~ ~~"""""r----....--..-~t-..---..---...--- ........----.IO

10001-~Hf---I-+-I---.---t----I---+----l

500

20001---k-1-k---1---k-1---1--\:--t----t---+----l

.4 200032

50001----+---it-....-t---.f4t--+---+--e,.--+--~1500

60001---1---+-+-+t---~-...+---+---+-..._I

1 300011----Hl-er--t---~--+---.....--+_--4_-_l ~~ ~OO •.e ::lE~ .ef 4000 £iQ §

500040003000200010007000L-__L--I-_.L-_-..l.L-__.L-J-_.l...-_-L....L-__-L...JL...----I

oPressure In kPa

Fig. 3. Pressure profiles at HGP-A. Steam flow in klb/h (kg/s in parentheses): (1) 64 (8.1), (2) 57 (7.2), (3) 48 (6.1), (4)39 (4.9).

136 P. Takahashi, A. Seki and B. Chen

Table I. Preliminary throlLled now data

Orifice Total mass Steam Steam Wellhead Wellheadsize flow rale flow rate quality pressure temperature

inches (mm) klb/h (kg/s) klb/h (kg/s) (It/D) psig (kPa) OF (OC)

8 (203) 101 (12.7) 64 (8.1) 64 51 (352) 295 (164)6 (152) 99 (12.5) 65 (8.2) 66 54 (372) 300 (167)4 (102) 93 (II.7) 57 (7.2) 64 100 (689) 338 (188)3 (76) 89 ( 11.2) 54 (6.8) 60 165 (1138) 372 (207)2Y2 (64) 84 (10.6) 48 (6.1) 57 237 . (1634) 401 (223)2 (51) 81 (10.2) 43 (5.4) 53 293 (2020) 419 (233)I~ (45) 76 (9.6) 39 (4.9) 52 375 (2585) 439 (244)

Table 2. Summary of preliminary test results and analyses

Kapoho geothermal reservoir(I) Liquid-dominated(2) Tight formation(3) Very high temperature. 350°C(4) High formation pressure, 13,790 kPa(5) Slightly brackish water(6) Potentially large reservoir(7) High silica content

HGP-A geothermal well(1) During flash borehole contains steam and water at saturation(2) Flashing occurs in formation(3) High wellhead pressure, 1103 kPa at 50 klb/h steam(4) Producing regions probably at bottomhole and 1323 m(5) Probably has severe skin damage(6) Potential power output, 3.5 MWe(7) Flows have increased with each test

Table 3. HGP-A power plant operation:March 1982 to August 1984

Operating hoursNon-operating hoursAverage available factor, IJ7DAverage generation, MWCapacity factor, lifo

20,1091,84391.52.4498.0

Table 4. Comparison with Barstow Solar One

Cost, SRating, MWNet output, kWh*

HGP-A

14 million3

50 million

Solar One

140 million10

2.4 million

*In approximately same length of time.

Hawaii Geothermal Applications Program 137

composition since the increase, which was probably due to a cleaning of scale deposition withinthe wellbore. However, there has been a gradual decline since the surge, with an asymptoticsuperimposition expected over time to match the normal decline.

Early monitoring of geochemistry as stated by Thomas (l985b) revealed that the salinity ofthe brine produced during the initial testing in 1976 was quite low-l040 mg/kg. Tritiumanalyses showed that the seawater component, based on chloride ion concentration, was about5010. However, subsequent testing has displayed an im:rease approaching 10,000 mg/kg. Thisincrease is interpreted to be the result of seawater intrusion as the chemistry of the seawatercomponent has been altered substantially: lithium, potassium and calcium ion concentrationshave been enriched, while magnesium and sulfate have been heavily depleted, with sodiumunchanged.

In contrast to the water chemistry, the changes-in the non-condensable gas concentrationshave been small: carbon dioxide, 1300 - ] 150 mg/kg; hydrogen sulfide, 950 - 850 mg/kg;nitrogen, ]30 - 120 mg/kg; and hydrogen, 13 - 11 mg/kg.

To date, a sum of over $14 million has been spent to explore, drill and develop the HGP-Afacility. Approximately $10 million has come from various federal agencies, with the remainderfrom State, County of Hawaii, HELCO and other partners (Department of Planning andEconomic Development, 1983).

Following the success of the HGP-A geothermal power plant, several wells were drilled byprivate companies less than 1.5 km from the HGP-A site (Fig. I). Even though relatively littledata have been released by these companies, all indications point to the availability ofgeothermal resources in these wells at higher steam qualities relative to the HGP-A well. Theprivate companies are currently in the resource confirmation phase. HELCO, in January 1985,rejected three proposals they received to build a geothermal plant, according to a HonoluluAdvertiser article (1985). However, a utility - private sector partnership is anticipated to bringadditional geothermal power on line by 1990.

GEOTHERMAL APPLICATIONS PROGRAMS

The majority of the geothermal resources in the world are applied to non-electric purposes.Most of these uses are in space heating/cooling, agriculture/aquaculture, and industrialprocesses. The leading consumer of geothermal energy for space heating is Iceland, where 75010of the population are supplied this option in their homes. District heating is also being seriouslyconsidered by as many as 40 different sites in the United States. Space cooling has been success­fully applied in New Zealand and at the Oregon Institute of Technology. Extensive agri­business related geothermal energy utilization occurs in the Soviet Union and in Hungary.Industrial applications can be seen in a wood and paper processing plant in New Zealand and adiatomaceous earth drying plant in Iceland. Some U.S. examples are an onion dehydrationplant at Brady Hot Springs, Nevada and a milk pasteurization facility at Klamath Falls, Oregon(Lund, 1984).

The future development of geothermal energy is not without problems. For example, thesilica in the liquid phase of the geothermal fluid can make disposal extremely difficult (Thomas,1982). Work has been done in New Zealand and the U.S. to seek an optimum set oftemperature, pressure and pH for reinjection. The Electric Power Research Institute will betesting a flash crystallizer separator this year in the Imperial Valley. A similar unit by Union Oilis also in operation at Salton Sea.

Considerable heat is wasted when using geothermal fluid only for electricity generation. Forexample, at HGP-A approximately 22,722 kg/h of 187°C and 1104 kPa geothermal water isdisposed, or 17.9 million kJ per hour, equivalent to nearly a million dollars per year of oil. With

"

138 P. Takahashi, A. Seki and B. Chen

private companies developing geothermal power plants at Puna there could someday be anabundance of geothermal flllids for direct heat applications.

Recent analyses have shown that the silica produced by HGP-A show attractive economicpotential. The particle-size. condition and quantity provide speculation that the revenues fromsilica alone ~ould match, if not exceed. the electricity sales. These early projections will betested and verified at the Puna Research Center (PRC).

The state of Hawaii, with federal support, is examining methods to transport the potentiallyabundant electrical energy to the island of Oahu where the vast majority of the state's popu~

lation reside and subsequently where energy demand is needed. One method is via anunderwater electric cable to transmit the surplus geothermal energy to Honolulu. Other energy

. bridges include liquid fuels production and hydrogen, both which are pegged for study at PRC.

NO!'I 0 PUNA: THE PUNA RESEARCH CENTER

In June 1984, Governor George Ariyoshi released $325,000 of capital improvement fundsappropriated by then State Representative (now senator) Richard Matsuura to build a facility toconduct geothermal applications research on the grounds of the HGP-A wellsite (Fig. 4). Alocal engineering firm has designed and managed construction of the facility. PRe will readyfor use by autumn 1985.

The design features include a wet chemistry laboratory, additional lab space and an office.An open area has been designated for geothermal research in which high pressure brine (1104kPa) will be provided for various experiments. Low pressure steam and brine (104 kPa) from asmall flash separator are expected to be installed in the second phase of this project. This

~o@

®octI®IC£]...._._.__.__.-._-_.__._.

Fig. 4. HGP-A wcll silc. (I) Puml Research Cenlcr site, (2) wcllhead, (3) separator, (4) callslic lanks, (5) power-planl,(6) H,S abalcmenl, (7) cooling lowcr, (8) detenlion pond, (9) sctlling pond, (10) visilor cenler,

Hawaii Geothermal Applications Program 139

facility will be housed, in a 12.2 x 15.2 m pre-fabricated building. Electricity (120 and 240 V),running water, lights, drainage, sanitation, compressed air and telephone service will also beprovided.

Use of the facility will be managed by the Natural Energy of Hawaii Board and assisted in theR&D program by the Hawaii Natural Energy Institute (HNEI) in cooperation with theUniversity of Hawaii at Hilo and with the support of the County of Hawaii, which hasappropriated $51,500 in cost-sharing funds. The State Department of Planning and EconomicDevelopment (DPED) is expected to also cost-share capital improvement monies as justified.

PRC will enable vital research and development to be carried out in both geothermalelectrical and non-electrical applications, such as dehydration of agriculture and aquaculturalproducts. The research programs at PRC will build on the results available at present at variousresearch institutions throughout the world. A Geothermal Research Advisory Task Force hasbeen formed, consisting of representatives from academia, utility companies, government, theprivate sector and the general community, and has identified the following areas as desirablefor research emphasis:(1) well and reservoir analysis of the Kapoho Reservoir,(2) silica inhibition, extraction and utilization,(3) hydrogen sulfide removal and utilization,(4) dehydration and food processing,(5) cold storage and ice making,(6) geothermal water and gas chemistry monitoring,(7) effect of HzS on plant, animal and human life,(8) liquid-fuel-from-biomass through geothermal heat process,(9) hydrogen production using geothermal heat and

(10) geothermal brine reinjection.

The facility could initiate industrial park or small business development utilizing the potentialelectrical power and heat available from the geothermal fluids. Table 5 is a summary of thekinds of applications anticipated from the waste effluent alone. As this area is suffering econ­omically through the recent closing of Puna Sugar Company, which cultivated 6070 hectares ofland, the initiation of possible new industries is of special importance. Some initial studies havebeen conducted examining the use of geothermal energy in commercial/industrial applicationsin Hawaii (Chen et al., 1982; Hirai and Associates, 1982; Humme et al., 1979). '

The College of Engineering, Pacific International Center for High Technology Research(PICHTR) and HNEI at the University of Hawaii at Manoa are initiating the Spark M.Matsunaga Fellows in Renewable Energy Engineering (FREE) program involving corporateand foundation endowment of teaching and research positions to advance the development ofrenewable energy technologies. The salary (provided by UHM) will be augmented to draw toplevel researchers to develop what is hoped to be the finest of the engineering faculty conductingresearch on critical renewable energy engineering problems in the most ideal of naturallaboratories, Hawaii. Hawaiian Electric Industries has donated $250,000 specifically to supporta FREE researcher in geothermal energy. A search committee has been formed and selection ofa scholar is expected by autumn 1985.

PlCHTR has established renewable energy research as one of the three research focal points.At' a planning meeting held in Honolulu, Hawaii in August 1984, representatives from theUnited States, the Republic of China (ROC) and Japan concluded that geothermal energyapplications research would be fruitful for all the participants and was identified as a highpriority area of emphasis. ROC has subsequently followed up and a cooperative agreement withHNEI is being drawn up.

140 P. Takahashi, A. Seki and B. Chen

Table S. Potential geothermal applications at the Puna Research Center

Application'

Drying of fish meal, timberDrying of farm products at high rates, food canningSugar processing, extraction of saltsFreshwater by distillationDrying and curing light aggregate cement slabs,

saline solutions for intravenous injectionDehydrated potato processing, drying organic materials,

seaweed, grass, vegetables, etc.Drying fish stock, intense deicing operationsMilk pasteurization, space heatingRefrigeration by low temperaturePoultry processing, animal husbandryPoultry hatching, brooding, mushroom growing, balneologyPapaya double dippingSoil warmingBiodegradation, fermentation, deicingFish hatching, farming

320 160284 140266 130248 120

230 110

212 100194 90176· 80IS8 70140 60122 50120 49J04 4086 3068 20

COMMUNITY GEOTHERMAL TECHNOLOGY PROGRAM (CGTP)

In addition to the more' traditional research projects to be conducted by university re­searchers, the Community Geothermal Technology Program has been funded by theDepartment of Energy to provide the opportunity for small businesses to develop geothermalenergy applications. The following is a summary of the key features of this program.

(1) ObjectiveThe Community Geothermal Technology Program will provide starter grants to individuals

and small businesses to use the Puna Research Center. As necessary or requested, universityfaculty members will be assigned to assist grantees in conducting research at PRC. By providingfinancial support and guidance throughout the project, uses ofgeothermal energy perceived asimportant by the community would be encouraged.

(2) Proposals .A re~uest for proposal will be publicized periodically, with the paperwork kept as simple as

possible. A format similar to the USDOE Appropriate Energy Technology Small GrantsProgram would be' used, requiring information on the qualifications of the proposer, adescription of the work to be done, a detailed budget and schedule, a brief narrative on theimportance of the project to the community and other pertinent information.

(3) Grant awardsSeed funds would be provided upon the review and approval of a written proposal by a board

consisting of representatives from the university, County of Hawaii, State Energy Division,"peer" reviewers from the Hilo/Puna communities who are familiar with the needs and desiresof the businesses and residents of the area and contributing sponsors. Grants shall not exceed$10,000 and may be awarded in any smaller amount.

(4) EligibilityAny individual, nonprofit organization, community group or small business, is eligible for

the program. Preference will be given to those living or working in geothermal districts.

Hawaii Geothermal Applications Program 141

(5) Coordination and assistanceTo ensure the quality of the work and facilitate the solution to any problems encountered by

the grantee, who may be inexperienced at submitting proposals and"performing work under agrant, a member of the University of Hawaii faculty could be asked to provide guidance andtechnical assistance.

The groundwork has been prepared by the State Department of Planning and EconomicDevelopment and HNEI to formulate a CGTP effort to maximize community use of PRe. TheState Energy Division of DPED, HNEI and the County of Hawaii who have collectively com­mitted $234,990 (in addition to the $325,000 construction cost) are in the process of securinganother $75,000 from private companies and have been awarded $175,000 by the USDOE toaccelerate the transfer of information and technology to industry and conduct basic research.

Through these means, ideas important to local small businesses would be represented in theresearch program at PRe. It is anticipated that the "seed" grants from CGTP would result innew or expanded business opportunities in the district, with a resultant increase in jobs. Thepotential for geothermal heat-related activities would encourage the efficient use of the region'sgeothermal resources, as well as making further geothermal development more attractive.

Reinforcing the research priority list mentioned earlier, the Island of Hawaii business andagricultural community has also identified projects of importance. These include cold storage,ice making, food processing and development of balneology enterprises (hotspring resorts,spas, etc.). The Puna area is predominantly agricultural, with commercial fishing also of someimportance, so projects in these fields excite the most community interest. It is hoped thatCGTP will spawn a variety of proposals including these topics, but also in areas which mayhave been overlooked by the established research community.

SUMMARY

A sum exceeding $30 million has thus far been expended to develop geothermal energy inHawaii. Very little of this amount has thus far been spent on non-electric applications.

One of the main purposes of PRC is to develop means by which waste and nuisance can beconverted into worth. A second objective is encouraging the community to help themselves tobuild the kinds of industries they most desire. PRC could be the model from which similarnatural energy laboratories can be established for other technologies.

REFERENCES

Chen. B. H. and Lopez. L. P. (1982) Final report on HGP·A Wellhead Generator Feasibility Project. GeOfher. Resollr.COl/neil Trans. (1,335-337.

Chen. B. H., Lopez, L. P., Kuwada, 1. T. and Farrington, R. J. (1980) Progress report on HGP·A Wellhead GeneratorFeasibility Project. CeO/her. ResOllr. Council frans. 4,491-494.

Chen, B. H., Lopez. L. P.• Farrington, R. J., Kuwada. J. T. and Ucmura, R. T. (1979) HGP-A Wellhead GeneratorFeasibility Projcct. Ceo/her. Resour. COl/neil Trot/s. 3, 103 - 106.

Chen. B. 1-1., Lopez, L. P.• King, R., Fujii, J. and Tanaka. M. (1982) Utilization of geothermal energy in tropical fruitprocessing. Departmelll of Planning and Economic Development, State of Hawaii.

Department of Planning and Economic pevelopment (19B3) State Energy Resources Coordinator 1982 annual report.State of Hawaii.

Hirai. W. A. and Associates (1982) Feasibilhy of an ice-making and cold storage facility using geothermal waste heal inPuna Dislfict. Island of Hawaii.

Honolulu Advertiser (1985) HELCO rejects 3 proposals for a geothermal plan!. p. A-3.Humme. J., Tanaka, M., Yokota, M. and Furumoto, A. (1979) Engineering and economic analysis for .he ulilization

of geothermal Iluids in a cane sugar processing plant. Final report, Puna Sugar Co., AMFAC Inc.Lund, G. W. (1984) Direcl use of geothermal resources. Unpublished manuscript.Pacific 100ernalionai Celller for High Technology Research (1984) Proc. of Technical Planning Mecting. University of

Hawaii at Manoa, HonolulU, Hawaii.

· I

142 P. Takahashi, A. Seki and B. Chen

Thomas, D. (l982) A geochemical case study of the HGP-A well: 1976 -1982. Proc. oj the Pacific Geothermal ConI.and FO/lrth New Zealand Geothermal Workshop, pp. 273 - 278.

Thomas, D. (l985a) Personal communications.Thomas, D. (1985b) Characteristics of the geothermal resource associated with the volcanic systems in Hawaii. Proc. oj

the 1985 Int. Symp. on Geothermal Energy and 9th Annual Meeting.Yuen, P. C., Chen, B. H., Kihara, D. H., Seki, A. S. and Takahashi, P. K. (1978) HGP-A reservoir engineering.

Hawaii Geothermal Project, University of Hawaii at Manoa.