Using
Geothermal
Energy
toComplywith
EPA’sClean
PowerPlan
AStateguideto
understandingthe
potentialofgeothermal
technologytoreduce
stateelectricityand
energysectoremissions
UsingGeothermalEnergy
toComplywith
EPA’sCleanPowerPlan
AStateguidetounderstandingthepotentialof
geothermaltechnologytoreducestateelectricity
andenergysectoremissions
GeothermalResourcesCouncil
GeothermalExchangeOrganization
GeothermalEnergyAssociation
December14,2015
Preparedby:
BenjaminMatek,RaniChatrath–GeothermalEnergyAssociation
RyanDougherty–GeothermalExchangeOrganization
Additionalsupportprovidedby:
PaulBrophy,BrianSchmidt,AnnaCarter,AndrewSabin,ElaineSison-Lebrilla,andRandyManion–Geothermal
ResourcesCouncil
Acknowledgements:
SpecialthankyoutoMariaRichardsfromSouthernMethodistUniversity(SMU)forsharingSMU’sdataand
researchforthisproject.CoverPhotosCourtesyofNREL.AllmapsinstateguidescourtesyofDr.AnnaCrowell,
UniversityofNorthDakota.
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
i
ExecutiveSummary
OnAugust3,2015,PresidentObamaandEnvironmentalProtectionAgency(EPA)announceda
federal Clean Power Plan. The Clean Power Plan (CPP) creates a flexible framework for state
control of strategies for reducing carbon pollution -- the largest contributor to global climate
change and the cause of an array of public health problems. Under the CPP, geothermal
technologies are eligible in a “Best System of Emission Reduction” (BSER) strategy. Where
suitable geothermal resources are available, states can build geothermal power plants, and
expand direct uses of geothermal heat. And geothermal heat pumps can contribute to
demand-sideenergyefficiencyprogramsineverystate.
Fossil fuel power plants are the largest source of carbon to our atmosphere. Geothermal
resources suitable for generating electricity, primarily found in the Western United States
(U.S.),canbeextremelyvaluablesourcesofclean,reliablepower.Geothermalenergyprovides
afirmbutflexiblegenerationresourceinapowersupplymarketfloodedwithotherrenewable,
butintermittent,generationtechnologies.Inadditiontoprovidingasecureindigenoussupply
of electricity, transmission system reliability, and a low-cost fixed price of power, geothermal
plantshaveverylowtononexistentcarbonemissions.InCalifornia,forexample,TheGeysers
and Imperial County geothermal plants supply baseload electricity while offsetting the
emissionsof11.6billionpoundsofcarbondioxideannuallythatwouldotherwisebeemittedby
fossilfuelplants.Thatisequivalentingreenhousegasemissionstotakingmorethan1,050,000
carsofftheroad.
Direct-uses of heat and hot water from geothermal resources can be used for a number of
purposes as demand-side efficiency technologies, including cooking, pasteurizing, space
heating,biofuelproduction,soilwarming,heatingandcooling,vegetabledrying,snowmelting
anddeicing,lumberorcementdrying,pulpandpaperprocessing,aquaculture,soilsterilization,
fabricdrying,refrigerationoricemaking,andgreenhouseheating.Usingdirect-usegeothermal
systems for these commercial purposes instead of fossil fuels helps states further reduce
emissions.
Lastly,geothermalheatpumps(GHPs),alsoknownasground-sourceheatpumps,usethenearconstanttemperaturesandtheinsulatingpropertiesoftheEarthjustafewfeetunderground
anddonotrequireaccessingadeepgeothermalreservoir.GHPsareamongthemostefficient
and comfortable heating and cooling technologies currently available and their use is
burgeoningnationwide.EnergyStar-certifiedgeothermalheatpumpsareover45percentmore
energyefficientthantraditionalsystemspoweredbyfossilfuels.GeothermalHeatPumpsare
clean,quiet,createnoindoorpollution,anduse25%to50%lesselectricitythanconventional
heatingorcoolingsystems.
The policy and regulatory structures discussed more fully in this document can speed
implementationofthesegeothermaltechnologiestocost-effectivelyachievestateCPPcarbon
reductionandotherstatecleanairprogramgoals.
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
ii
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
iii
Contents
ExecutiveSummary.......................................................................................................................................................ii
Introduction..................................................................................................................................................................1
SECTION1:GeothermalElectricity..............................................................................................................................3
Environmental&EmissionBenefits.........................................................................................................................4
Employment&EconomicBenefits...........................................................................................................................5
Firm&FlexiblePowerPotential...............................................................................................................................5
CostofGeothermalPower.......................................................................................................................................6
ProjectCost..........................................................................................................................................................6
PowerPurchaseAgreements...............................................................................................................................7
RecommendedGeothermalStatePolicies&Practices............................................................................................7
Research&RiskReduction..................................................................................................................................7
StateAgencyPolicy&Law...................................................................................................................................7
PublicUtilityCommissions,Contracts&theMarket...........................................................................................7
ValuingGeothermalPower..................................................................................................................................8
SECTION2:GeothermalDirectUse.............................................................................................................................9
ValuesandBenefits................................................................................................................................................10
Economics&Costs.................................................................................................................................................10
CaseStudies...........................................................................................................................................................11
KlamathBasinBrewingCo.................................................................................................................................11
ElkoNevadaDistrictHeatingSystem.................................................................................................................11
Boise,IdahoGeothermalHeatingDistrict.........................................................................................................12
SECTION3:GeothermalHeatPumps........................................................................................................................13
ValuesandBenefits................................................................................................................................................14
RecommendedNewGeothermalStatePolicies&Practices.................................................................................15
GeothermalHeatPumpCosts................................................................................................................................16
CaseStudies...........................................................................................................................................................17
IKEAinKansasCity&DenverArea....................................................................................................................17
DOCUMENTANDFACTSHEETREFERENCES................................................................................................................18
APPENDIXA:IllustrationsofGeothermalPowerTechnologyTypes.........................................................................21
APPENDIXB:State-SpecificGeothermalPotential.....................................................................................................24
Arizona...................................................................................................................................................................24
California................................................................................................................................................................24
Colorado.................................................................................................................................................................24
Idaho......................................................................................................................................................................24
Montana.................................................................................................................................................................24
Nevada...................................................................................................................................................................24
NewMexico...........................................................................................................................................................24
Oregon...................................................................................................................................................................24
Utah........................................................................................................................................................................24
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
iv
Introduction
On August 3, 2015, President Obama and the Environmental Protection Agency (EPA)
announced the Clean Power Plan. The Clean Power Plan will reduce carbon pollution from
power plants, the nation’s largest source of carbon pollution that leads to an array of public
healthproblemsandexacerbatesglobalclimatechange.Onthesamedate,theEPAissuedfinal
CarbonPollutionStandardsfornew,modified,andreconstructedpowerplantsandproposeda
FederalPlanandmodelruletoassiststatesinimplementingtheCleanPowerPlan.Theseare
thefirst-evernationalstandardsthataddresscarbonpollutionfrompowerplants.
UndertheCleanPowerPlan,statesmustdevelopandimplementplanstocomplywiththese
rules to ensure the power plants within their state meet their state-specific goals for carbon
pollutionby2030.ThroughouttheU.S.,geothermalenergyisanexcellentwaytocomplywith
EPA’scarbonreductiongoals.Tappingintoenergygeneratedfromtheearth’scrustisaclean,
emissionfreeandreliablewaytogenerateelectricityateconomicalratesacrosstheU.S.with
minimalimpacttotheenvironment.
To comply, states may choose between two types of plans. Targets are expressed as either
emissionrateormassofCO2reduced.
o Emission standards plans include source-specific requirements ensuring all affected
powerplantswithinthestatemeettheirrequiredemissionperformance.
o Statemeasuresplansincludeamixtureofmeasuresimplementedbythestate,suchas
renewableenergystandardsandprogramstoimproveresidentialenergyefficiencythat
arenotalreadyincludedasfederallyenforceablecomponentsoftheplan.
Inbothplantypes,statescanusegeothermalresourcesoutlinedintheBestSystemofEmission
Reduction(BSER)bybuildingpowergenerationfacilitieswheretheseplantsareavailableorby
implementingdirectuseandgeothermalheatpumpdemand-sideenergyefficiencyprograms.
If states are to choose demand-side efficiency measures, geothermal direct-use and heat
pumpsareanexcellentoptionforreducingconsumptionofelectricityforheatingandcooling.
Geothermal heat pumps are cost-effective and proven technologies that reduce the need for
morecarbon-intensivefuelstocoolorheathomesandbusinesses.
Whenlow-temperaturegeothermalresourcesareavailable,geothermaldirect-usetechnology
canbeusedforcooking,pasteurizing,spaceheating,biofuelproduction,soilwarming,heating
and cooling, vegetable drying, snow melting and deicing, lumber or cement drying, pulp and
paperprocessing,aquaculture,soilsterilization,fabricdrying,refrigerationoricemaking,and
greenhouseheating.
Thenumberofstatesthathavehigh-temperaturegeothermalresourcesateconomicaldepths
capable of generating electricity are more limited. In general, there are three types of
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
1
geothermal power conversion technologies, dry steam, flash, and binary (or organic Rankine
cycle).
DrySteamPlants:Indrysteamplants,naturallyoccurring,high-pressuresteamshootsupfrom
thedrysteamreservoirandusedtoruntheturbinesthatpowerthegenerator.
Flash Plants: In flash plants, steam is separated from high-pressure and high-temperature
geothermal fluids (hot water and steam). The steam is delivered to a turbine that powers a
generator. The liquid (condensed from the steam after passing through the turbine) and
remaininggeothermalwaterareinjectedbackintothereservoir.
BinaryPlants:InbinaryorORC(i.e.,organicRankinecycle)plants,theheatistransferredfrom
thehotwatertoanorganicworkingfluidthathasaboilingpointlowerthantheboilingpoint
of water. The working fluid is vaporized to run the turbine. The geothermal water is never
allowedtoreachtheatmosphere-100%isinjectedbackintothereservoir.Inallsystems,the
injectedfluidisneverallowedtomixwiththeshallowgroundwatersystem.Forillustrationsof
thesetypesoftechnologiespleaseseeAppendixA.
AllofthesegeothermalsystemscanbeincludedaspartofEPA’sCleanPowerPlanandwillbe
essentialformeetingcarbonreductiontargetsacrosstheU.S.Geothermalenergyisestimated
to currently supply 75,862 terrajoules per year (TJ/yr), or 21,074 gigawatt-hours per year
(GWh/yr)ofheatenergyintheU.S.fromdirectheatusesandgeothermal(ground-source)heat
pumps. The total low temperature, heat resource capacity of the U.S. is estimated to exceed
17.5gigawattsthermal(GWt).1
Forgeothermalresourcescapableofproducingelectricity,theUnitedStatesGeologicalSurvey
(USGS)estimatesthereareover9GWeofidentifiedresources,andover30GWeofunidentified
resources across 13 western states.2If Enhanced Geothermal Systems (EGS), co-production,
andgeo-pressuredsystemsareincluded,theseestimatesexpandtoanotherdozenstatesand
nearly quadruple. In places such as California, geothermal power already contributes
substantially to state climate goals. For example, the Geysers and Imperial County, California
geothermal plants supply baseload electricity while offsetting the emissions of 11.6 billion
poundsofcarbondioxideannuallythatwouldotherwisebeemittedbyfossilfuelplants.That
isequivalentingreenhousegasemissionstotakingmorethan1,050,000carsofftheroad.3
Boyd,etal.,2015.
Williams,etal.,2008
3
McGuire,etal.,2015.
1
2
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
2
SECTION1:GeothermalElectricity
Section1
Geothermal
Electricity
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
3
Environmental&EmissionBenefits
Geothermal power generates extremely low emission rates, especially when compared with
traditional fossil fuels that involve direct combustion of fuels. Binary power plants, which
represent most of the geothermal plants that have come online recently, have near-zero
greenhouse gas emissions and minimal particulate matter emissions.4When considering life
cycleemissions,ArgonneNationalLaboratoryfoundbinarygeothermalpowerplantstobeone
ofthecleanestformsofenergy.5Flashanddrysteamgeothermalpowerplantsalsorepresenta
significantimprovementovercoalandnaturalgas,asshowninTable1.6Ingeneral,emissions
fromgeothermalplants,whentheydooccur,areseveralordersofmagnitudelessthanthoseof
fossilfuelfacilities.
WithintheU.S.,geothermalplantsareusuallyfoundinregionsoftectonicandvolcanicactivity
andcanbeco-locatedwithnaturalhotspringsandsimilarmanifestationsthatnaturallyrelease
greenhouse gases. The naturally occurring emissions from these from these features often
exceedsthosefromthegeothermalplants.7
Table1:EstimatedEmissionLevelsbyPollutantandEnergySourceofPowerPlants8
[lbs/MWh]
DrySteam*
Flash*
Binary
NaturalGas*
Coal*
CO2
60
396
0
861
2200
CH4
0
0
0
0.0168
0.2523
PM2.5
0
0
0
0.1100
0.5900
PM10
0
0
0
0.1200
0.7200
SO2
0.0002
0.3500
0
0.0043
18.75
*Note:TheseestimatesareforatypicalCaliforniageothermalpowerplant.Thefossilfuelemissionestimatesareforatypical
fossilfuelfiredpowerplantintheU.S.
Theemissionmostfrequentlyassociatedwithgeothermalpowerproductionishydrogensulfide
(H2S),agasthatoccursnaturallyinvaryingconcentrationsingeothermalsystems.H2Soxidizes
into sulfur dioxide and sulfuric acid when released into the atmosphere. Known for its
distinctive “rotten egg” smell, hydrogen sulfide is a natural component of many volcanic and
geothermal systems. Today, hydrogen sulfide abatement systems, such as LO-CAT and
Stretford, are used extensively throughout the industry and have demonstrated a removal
efficiency of more than 99.9% 9 . Through such systems, hydrogen sulfide is converted to
elementalsulfur,whichcanbeusedasafeedstockforfertilizersorasasoilamendment.
Not only are emissions minimal to non-existent but the land footprint is tiny as well.
Geothermal power uses very little land compared to other energy sources, particularly when
weighed against other renewables. Unlike power generated from solar, wind, and biomass
sources,whicharepredicatedupongatheringdiffuseambientenergyoverlargetractsofland,
(Matek,2013)
(Sullivan&Wang,2013)
6(Matek,2013)
7(Bertani&Thain,2002)
8(Matek,2013)
9(Nagl,2009)
4
5
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
4
geothermalexploitsaconcentrated,subterraneanresource.Geothermalplantfacilitiesuseless
surfaceareaforcomparablelevelsofpower.
Arecentpaperestimatestheintensityoflanduseassociatedwithvariousenergysourcesbased
on the anticipated state of technology in the year 2030. Assuming 8,766 hours in a year,
geothermalpower’sestimateduseof66km2/GWislowerthancoal(85),solarthermal(134),
natural gas (163), solar voltaic (323), petroleum (392), hydropower (473), wind (632), and
biomass(4,760).10Geothermalresourcesdonotrequiretransportationoffuelslongdistances
by pipeline, highway, rail, or across oceans in tankers. They are homegrown resources with
powerplantfacilitieslocatedatthereservoirsitesupplyingelectricitytoregionalgrids.
Employment&EconomicBenefits
• Geothermal plant construction employs about 3.1 person-years per MW; the
manufacturingoftheequipmentrequiresanadditional3.3person-yearsperMW.
• Geothermalpowerplantsemployabout1.17personsperMWateachoperatingpower
plant. These are permanent jobs that last the entire 30-50 year lifetime of the power
plant.
• Intotal,addinggovernmental,administrative,andtechnicalrelatedjobs,thegeothermal
industryemploysabout2.13personsperMW.
• Anaverage50MWfacilitywillcreatepermanentemploymentforabouta100people.
• In 2013, U.S. geothermal power producers paid $29 million dollars in annual property
taxes,including$21milliondollarstotheStateofCaliforniaalone.
• Geothermal paid about $26 million in rents and royalties to state, federal and local
governmentsnationwidein2014ofwhichonequarterisreturnedtobenefitstateand
localcountygovernments.
• Overthecourseof30to50yearsanaverage20MWfacilitywillpaynearly$6.3to$11
milliondollarsinpropertytaxes.
Firm&FlexiblePowerPotential
With well-structured and appropriately priced contracts, geothermal plants can provide both
flexible and baseload power production. Although traditionally operated as a source of
baseload power, the advancement of power plant and control technology allow geothermal
power plants to work in several different modes, such as grid support, regulation, load
following, spinning reserve, non-spinning reserve, and replacement or supplemental reserve.
Thesemodesarecommonlyreferredtoas“ancillaryservices,”whichareperformedbyentities
that generate, control and transmit electricity in support of the basic services of generating
capacity,energysupplyandpowerdelivery.Thefutureelectricitygrid,dominatedbyvariable
energyresources(primarilywindandsolar),willneedtechnologiesthatcanbebothbaseload
andflexible.
10
(McDonald,Fargione,Kiesecker,Miller,&Powell,2009)
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
5
While most geothermal plants generate baseload electricity, flexible geothermal operations
havebeendemonstratedatseveralprojects,includingthePunaGeothermalVentureplantin
Hawaii which generates 38 MW, and has contracted 16 MW of flexible capacity. This plant
provides ancillary services for grid support that are identical to those of the existing oil-fired
peakgeneratingresourcesontheBigIsland.Thisplantisconsideredafirst-of-its-kindandcould
be expanded to other facilities given the right contracts and retrofits. 11 Additionally,
geothermal plants at the world’s largest geothermal field – The Geysers, located in northern
California – have operated in various modes, including traditional baseload, peaking and load
following.Theflexiblemodeswereofferedasanappropriateresponsetotheneedsofoneof
theutilitiespurchasinggeothermalpowerfromTheGeysers.Flexibleoperationsceasedinthe
early1990sinresponsetoacombinationoflowdemandandlowercostsofgenerationwithin
theutility’ssystemfromhydro,coal,andnaturalgaspowerplants.12
In general, it’s currently more economical for geothermal developers to operate geothermal
plantsunderbaseloadpowerpurchaseagreementsfortheirplants.However,somesuggestions
inthegeothermalindustryonhowtorespondtoutilitiesrecentcallforgeothermalpowerto
besuppliedinmoreflexiblecontractsincludethefollowing:
• Utilitiescouldbuycapacityfromageothermalplantandthenpurchaseenergyasthey
regulate its output, within the plant’s technical limits. Flexible contracts with pricing
structuresthataccountforgeothermalenergy’suniquecapitalstructurewouldenable
flexiblegeothermalpowertocompetewithnaturalgas.
•
Utilizingstoragetechnologiesforgeothermalpowerplantstostorepowerandrelease
theelectricityasneeded,insteadofconstantlyexportingelectricitydirectlytothegrid.13
•
Ancillaryservicesinthepasthavetraditionallybeenprovidedbyfossilfuelsourcessuch
asnaturalgas.Inmanycasesthesecontractsareveryhighlypricedduetospotmarket
gaspurchases.Renewablescanofferamoreeconomicalalternative,sincethereisno
volatilityinfuelpricing.
CostofGeothermalPower
ProjectCost
Thecostofatypicalgeothermalpowerprojectishighlydependentonseveralfactorsincluding
drilling depth, geology, temperature and project size. However, a typical 50-MW greenfield
projectinageothermalfieldwithwellsofaround2km(6500ft)indepthwillcostbetween2.8-
5.5millionUS$/MW.Thisincludesthecostofeverythingfrompreliminarysurveystoturbine
construction.14Atypicalnew25-35MWprojectintheU.S.costsbetween$125-150million.
Acommonpracticeistobuildexistingprojectsincrementally,eitherbyaddingmorewellsand
more turbine generator modules to an existing (brownfield) power project, or adding a
“bottoming cycle” unit to the plant using existing wells. The advantage of this development
(Nordquist,etal.,2013)
(Cooley,1996)
13 (McGrail,2015)
14 (Gehringer&Loksha,2012)
11
12
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
6
approachisthatitimprovesthesustainabilityofthereservoirandisoftenalowercostwayof
building geothermal projects. If built in this manner, projects fall on the lower end of the
spectrumoftenrangingfrom1.5-4millionUS$/MW.15
PowerPurchaseAgreements
Data collected by GEA and the US DOE Geothermal Technology Office (DOE) shows that
projectsintheU.S.havesignedpowerpurchaseagreements(PPAs)withutilitiesinthelastten
yearstypicallyrangingbetween$17.76-$101.95perMWh.Thesepowerpurchaseagreements
arenormallyforbase-loadpowercontracts.Thelow-endpricewasforanolder,existingfacility
andislikelybasedonCalifornia’sShortRunAvoidedCost.Thehigh-endpricesarefornewer
binaryprojectsthatwerebuiltonlower-temperatureresourcesthatweresmallerinsize.
RecommendedGeothermalStatePolicies&Practices
ForanystateutilizinggeothermalenergyordirectusetocomplywithEPA’s111(d)CleanPower
Plan, the GEA recommends the following practices be implemented to ensure smooth and
expedientdevelopmentofthetechnology.
Research&RiskReduction
• Publishpublicexplorationdatainthepublicdomainforcompaniestouseandverify.
• Initiateactiontodevelopresourceinformation,eitherasdonorsorgovernments.
• Donorsandgovernments(bothnationalandlocal)mayneedtoparticipateindrillingrisk.
• Support research in energy storage schemes to further enhance grid stability while
creatingagoodeconomicenvironmentforgeothermalandotherrenewables.
StateAgencyPolicy&Law
• Coordinateinstitutionsintowhatiseffectivelyonebodygoverninggeothermalresource
development.
• Minimize the number of agencies or institutions involved with regulation—“one-stop
shopping”istheidealmodel.
• Developinstitutionalcapacityandcapability.
• Develop laws and regulations that create an investment environment where risk and
returnarematchedforgeothermaldevelopment.
• Developers who make significant investments or resource discoveries on state lands
underexplorationpermitsshouldhavearighttoanegotiatedlease,orrightofmatching
highbidsunderpublicauctions.
• Developers of public lands should have a limited time to act on permits, or leases can
terminate.
PublicUtilityCommissions,Contracts&theMarket
• Take the current electricity market into account. There must be a market for the
electricity.Generationgrowthmustbeaccompaniedbygridgrowth.
15
UnpublishedGEA&DOEdata.
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
7
• Promotetheuseofdemand-side(electricalequivalent)geothermalsolutions(geothermal
heatpumpsanddirectusesofthermalwaters)todisplaceelectricitygenerationsources
thatemitlotsofcarbondioxide.
• WorkwiththestatePublicUtilityCommissionstoensurethatutilitiessolicitgeothermal
power and offer PPAs that attract geothermal developers. These contracts should
recognizealltheuniquevaluesgeothermalpowercanprovideanelectricitygridsystem,
includingancillaryservice,firmandflexiblepower,reliabilityandreductionoflinelosses
neartheendsofthelines.
• Understand that geothermal is traditionally and most efficiently operated as base-load
power (providing grid stability for states with intermittent renewables), but also can
operateinflexiblemodes(forloadfollowing).
ValuingGeothermalPower
• Whengeothermalplantsareintendedtobeoperatedinaflexible,load-followingmode,
contracts should be negotiated to include payment schedules that define the price of
powerinresponsetoadispatchsignaltransmittedbytheindependentsystemoperator
orotherload-servingentity.
• To increase the ability of geothermal plants for frequency regulation (i.e., ramping
generation assets up or down over a period of a few minutes), power pricing in future
contractsshouldbenegotiatedtoincludepaymentsspecificallyforfrequencyregulation
services.
• When comparing geothermal power to other renewables during procurement, it’s
important to consider all the values of geothermal power, such as: ancillary services,
geothermal’s minimal integration cost, environmental attributes, and economic benefits
thatdistinguishitfromtheintermittentrenewablesandfromcarbonemittingresources.
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
8
SECTION2:GeothermalDirectUse
Section2
Geothermal
DirectUse
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
9
ValuesandBenefits
Geothermalresourceshavebeenuseddirectly,fortheirheatforcenturies.Themostfamous
examplesmightbetheRomanbathhousesofEuropebuiltthroughouttheRomanEmpire.In
modern direct-use systems, a well is drilled into a geothermal reservoir to provide a steady
streamofhotwater.Thehotwaterisbroughttothesurface,andamechanicalsystem—piping,
aheatexchanger,andcontrols—deliverstheheatdirectlyforitsintendeduse.Projectscanbe
scaled to any size, and can range from an individual home, to a single greenhouse or
aquaculturepond,toalargedistrictheatingsystem.
These
applications
decrease
electricity demand by using an
already hot and sustainable
resource rather than converting
electricity or fossil fuels into heat.
The use of low- to moderatetemperature fluids, typically 380C
(1000F) to 1500C (3020F) are used
for
direct
use
projects.
Approximately 85% of identified
resources in the U.S. are below
930C. These resources are more
likely to be located near potential
users than traditional power
resources since they are more
widespread, often discovered
during conventional water well
drilling, and are designed with
Ball State Central GHP. Photo courtesy of Geothermal Exchange Organization
conventional
equipment.
off-the-shelf
The main uses of direct-use technology is industrial applications, agricultural drying, district
heating,spaceheating,greenhouses,aquaculture,resortsandspas,snowmelting,andcooling.
Currently in the U.S. there are 19 geothermal district heating systems with several additional
under construction, over 2000 individual heated buildings, 7 industrial and agricultural drying
stations, 45 greenhouse complexes, 51 aquaculture operations, 242 resorts and spas, and 6
snowmeltingprojectstheusegeothermaldirect-usetechnology.16
Economics&Costs
Everygeothermaldirect-useprojectisuniqueandshouldbecustomengineered.However,that
doesnotaddsubstantiallytotheircost.Thesesystemsareoftennotthatcomplicatedandcan
bebuiltwithoff-the-shelfcomponentsandequipmentcommonlyavailable.Itisthereforehard
16
(ToniBoyd,2015)
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
10
to generally apply standard costs for all systems as can be done for electricity or fossil fuel
systems. The economics of a project often depend on the user’s needs, geothermal fluid
temperaturesandflowrates,priceoftheequivalentfossilfuelheatingsources,andavailability
ofgovernmentincentives.Generally,thelargerthesystemneeded,thehigherthepricewillbe
foranalternativefossilfuelsystemforthesamepurpose.Furthermore,thebetterthequality
ofthegeothermalresourcesnearby,themoreeconomicthesesystemsbecome.
Table2:TypicalCostsofExampleGeothermalDirect-UseSystemsbyType17
Application
ResidentialSpace
Heating*
SpaceHeating*
DistrictHeating
GreenhouseHeating
AquaculturePond
Heating
Capital
$/kW
Cost/year
$/kWyr
O&M
$/kWyr
Total
$/kWyr
TypicalCapacity
Factor
UnitCost
cents/kWh
800
71.1
7.1
78.2
0.29
3.08
500
650
250
44.4
57.7
22.2
4.4
5.8
2.2
48.8
63.5
24.4
0.25
0.30
0.25
2.23
2.42
1.11
200
17.8
1.8
19.6
0.69
0.32
Note:Basedon30-yearlifeat8.0%interestandO&Mat10%ofcapitalcost.Theabovecostsincludeashallowwell(<984ftor300m)and
noretrofitcosts;however,costcanvarybyasmuchas100%dependingonthelocalgeology,hydrology,buildingconstruction,and
infrastructure.
*Assumesoneproductionandoneinjectionwellforasinglebuilding
**Heatpumpfiguresareconsideredonlyfortheheatingmodeandthecapacityfactorisanation-wideaverage.
CaseStudies
KlamathBasinBrewingCo.
The Klamath Basin Brewing Co utilizes a local geothermal district heating system in Klamath
Falls,Oregon.Onpeak,thecompanyusesabout1,700thermsofgeothermalenergyamonthat
acostof$1,360.ThissystemsavesKlamathBasinBrewingabout$1,190amonthduringtheonpeakseason.Duringtheoff-peakseason,thecompanysavesabout$300amonth,comparedto
generatingthesameheatwithfossilfuels.18
ElkoNevadaDistrictHeatingSystem
ThesysteminElko,Nevada,firstbeganconstructionin1982.Itcurrentlyservices19residential
andcommercialcustomersincludingacommerciallaundry,asewagetreatmentplant,andan
industrialpark.Thesystemcostabout$1.4million.Thecustomersarechargedabout$1.50per
1000gallonsofwaterusepumpedthroughthesystem.Thesechargesequatetoabout30%of
thecostofnaturalgas.19
(Lund,2015)
(Lund,2015b)
19 (Lund,2015a)
17
18
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
11
Boise,IdahoGeothermalHeatingDistrict
BoisePublicWorksDepartmentadministersBoise’sGeothermalHeatingDistrict.Thissystemis
thelargestandoldestdirect-usesystemintheU.S.Fourindependentheatingdistrictssupply
energy-efficientheattoover65businessesinthedowntowncorearea.Thecostofextending
thesupplyandreturnlinesisabout$50,000-$85,000percityblockinBoise.20
20
(Neely,Galinato,&Johnson,2006)
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
12
Section3
SECTION3:GeothermalHeatPumps
Geothermal
HeatPumps
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
13
ValuesandBenefits
According to the Department of Energy, buildings are the largest single sector of total U.S.
energy consumption. The buildings sector accounted for over 40% of primary energy use in
2010 and consumes approximately one third more energy than either the industrial or
transportation sectors.21 Some 60% of the energy used in buildings is for “thermal loads.”
Thermalloadsaretheamountofenergyneededtobeaddedorremovedfromaspacebythe
heating,ventilationandairconditioning(HVAC)systemtokeeptheoccupantscomfortable.A
thirdofthatU.S.thermalloadenergy–over3quadrillionBTUs–issatisfiedwithelectricity.
Given the high proportion of
energy and electricity used by
buildings
in
the
U.S.,
Geothermal Heat Pumps
(GHPs) offer a unique and
highly efficient renewable
energy technology for heating
and cooling. GHPs use the
natural insulating properties
underground, the latent solar
energystoredintheearthand,
below20ft,geothermalenergy
tomeetthethermalneedsofabuildingthroughaprocesscalled“geothermalexchange.”By
drawing on this stored and ever-regenerating solar and geothermal energy the space
conditioning requirements of a building can be met with a fraction of the energy normally
requiredbyconventionalHVACequipment.Theearthiswarmerinwinterthanistheair,and
coolerthantheairinsummer.
MostGHPsworkbycirculatingwaterinaclosedsystemthrougha“loopfield”ofdurable,highdensity polyethylene pipe installed horizontally in the ground adjacent to or even vertically
beneathabuilding.ThereareothertypesofGHPsystemsthatusealoopfieldplacedinwater
wellsorabodyofwatertoachievethesamegeothermalexchange.AnotherexampleofaGHP
isa“directexchange”system,whichusesasmallerloopfieldofcopperpipethroughwhicha
refrigerantinsteadofwateriscirculated.AllofthesedifferenttypesofGHPsystemsaresimilar
inthattheyutilizethestabletemperatureoftheearthtomeettheheatingandcoolingneeds
ofabuilding.Inthewinter,storedthermalenergyisdrawnoutoftheearthandusedtomeet
thebuilding’sheatingneedsandinthesummer,thatprocessisreversedandbuildingheatis
rejectedtotheearth.
According to the U.S. Environmental Protection Agency (EPA), “Geothermal heat pumps are
amongthemostefficientandcomfortableheatingandcoolingtechnologiescurrentlyavailable
. . . Energy Star-certified geothermal heat pumps are over 45 percent more energy efficient
21
(U.S.Dept.ofEnergy,2012)
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
14
thanstandardoptions.”22AndaccordingtoDOE,“ThebiggestbenefitofGHPsisthattheyuse
25%to50%lesselectricitythanconventionalheatingorcoolingsystems.Thistranslatesintoa
GHPusingoneunitofelectricitytomovethreeunitsofheatfromtheearth.”23
Byusingtheearth’sfreerenewablethermalenergy,GHPscanhelplessentheloadonelectrical
grids. This fact is especially true on hot summer days when consumer demand for air
conditioningspikesandpowergenerationresourcesarestrained.GHPsflattenpeakdemand
and reduce peak-load generation capacity that must be installed adding stability to the grid.
Peakenergyloadsarethemostexpensive.
Inadditiontotheeffectsontheelectricalgrid,GHPssignificantlyreducecarbonemissions.A
2010studyfromOakRidgeNationalLaboratoryshowedthataggressiveretrofittingofallsinglefamily homes across the country
withGHPswouldavoidtheneedto
build up to 48% of new electric
generation capacity projected
nationwide by 2030. 24 Such a
deployment of GHPs would save
$38 billion annually on consumer
utility bills and slash projected CO2
emissions by 45%. The Oak Ridge
study found that one ton (12,000
BTU/hr) of GHP capacity over a 20
year operating cycle avoids 21
metric tons of CO2 emissions. The
significant emissions reduction
capability of GHPs makes them a
technology type uniquely suited to
meetthegoalsofstatesseekingpoliciestocomplywithEPA’s111(d)CleanpowerPlan.
RecommendedNewGeothermalStatePolicies&Practices
States have a number of options available for compliance with the EPA’s 111(d) Clean Power
Plan.GHPsareoneofthemostapplicabletechnologiesforcomplianceastheyareademandsideefficiencytechnologythatcanbedeployedinall50states,andhaveaproventrackrecord
asthemostefficientandrenewableheatingandcoolingtechnology.Thefederalgovernment
recentlyrecognizedthethermalenergyutilizedbyaGHPasasourceofrenewableenergyand
instructed government agencies to consider their use a method of meeting energy savings
goals.
StateswishingtoincorporateGHPtechnologyintotheirplanforCPPcomplianceshouldadopt
thefollowingrecommendations:
(EnergyStar,2015)
(USDept.ofEnergy,2015)
24 (XiaobingLiu,2010)
22
23
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
15
• AmendstateRenewableEnergyPortfolioStandardstorecognizetherenewablethermal
energyproducedbyGHPsandcreateprogramstomeasureandcalculatetheaggregate
ofthisrenewableenergyforallcommercialandresidentialinstallations.Instateswhere
GHPsarenotincludedintheEnergyEfficiencyPortfolioStandard,thestandardshouldbe
amendedtoincludeGHPs.ByaddingGHPstothesestandards,statesareabletomore
easilymeettheirsRPSgoalsaswellasCPPtargets.
• RecognizetheuniqueabilityofGHPstosignificantlylowerelectricutilitypeakdemand.
Byderivingthebulkoftherequiredthermalenergyforheatingfromthelatentsolarand
geothermal energy stored in the earth, GHPs reduce the burden on power generation
facilities.Andinthecoolingmode,GHPsrejectabuilding’sheattothegroundinsteadof
outside air, cutting consumption and decreasing demand on strained generation
facilities.OnerecentDOEstudyshowedthatahomewithaGHPsystemgets75%ofits
heatingenergyfromtheearth.
• RecognizethecarbonemissionsreductionattributabletoGHPs.TheDOEhasperformed
studies that verify the unique ability of GHP technology to reduce greenhouse gas
emissions. Widespread GHP adoption can dramatically diminish the level of carbon
releasedintotheatmosphere.
• Encourage public utilities to support GHP deployment through on-bill financing
programs, special rate designs, and homeowner rebates. With focused incentives,
utilitiesareabletodeliverrealandlastingsavingstohomeownersandbusinesseswhile
meetingtheirowndemandreductiontargets.
• RecognizethelargepercentageofenergythatisdevotedtoHVACapplicationsandseek
toimplementthemostefficient/renewablesolutionsavailable.
GeothermalHeatPumpCosts
Geothermal heating system prices can vary depending on the type of ground heat exchanger
(usually vertical or horizontal), geographic location and on-site geological conditions. On
average,atypicalhomeof2000squarefeetwillrequire4tonsofheatingandcoolingcapacity
withanaveragesysteminstallationcostbetween$5,000and$7,500perton.
Anotherwaytoexpresscostwouldbebythetypeofheatpumpsysteminstalled.Geothermal
heatpumpcostsfora4-tonunit:
• Closedloopwatertowater= $34,000($8,500/ton)
• Openloopwatertowater= $28,000($7,000/ton)
• Closedloopwatertoair=
$28,800($7,200/ton)
• Openloopwatertoair=
$22,000($5,500/ton)
• Directgeoexchange= $16,000($4,000/ton)
These are average numbers and will vary depending upon local drilling or excavation costs.
WatertowaterGHPinstallationcostsincluderadiantflooring.Closedloopwatertoairisthe
mostfrequenttypeofinstallation(costshownincludesductwork).Openloopwatertoairisa
typical “pump and dump” system. Direct geoexchange uses copper pipe underground, but
excavation/drillingcostsarelower.
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
16
Ingeneralfourfactorsdeterminethecostofaheatpumpinstallationinahomeorcommercial
building.25
1. SizeoftheHome/Building–Thelargertheareacovered,themoreheatingandcooling
thebuildingwilldemand.
2. Size of the Heat Pump - Based on the size of the home, insulation, and climate the
amountofheatingandcoolingneedediscalculated,whichinturnenablesacontractor
tocalculatethesizeoftheheatpump.
3. Size of the Loop Field-Thesizeofthesystem(3-ton,4-ton,etc.)alongwiththelocal
climatewilldictatetheamountofpipethatneedstobeinsertedintotheearth.
4. Usability of Current Ductwork - In most cases, existing ductwork requires little to no
adjustment to be suitable for geothermal heating and cooling. However, if existing
ductworkisnotinplace,thanthehomeownerorbusinessownerwillneedtoincurthe
fullexpenseofinstallingit.
CaseStudies
IKEAinKansasCity&DenverArea
IKEA globally by January 2015, installed more than 300,000 solar panels, owns/operates
approximately137windturbinesinEurope,andhasgeothermalsystemsatapproximately50
locations.AttheDenverlocationinCentennial,Colorado,IKEAdrilled130boreholestoadepth
of500feet.Thecentralplantincludesten,35-tonwater-waterheatpumpsthatdriveavariable
airvolumesystemformostofstoreandnine1,500gallonicestoragetanks.AttheKansasCity
location in Merriam, Kansas, 180 boreholes were drilledto a depth of 600 fet. The system in
Kansas City is the building’s primary source of heating and cooling. These two systems are a
great demonstration of the economic viability of installing and operating geothermal heat
pumpsystemsonalargecommercialscale,intwoverydifferentstates,insteadofusingfossil
fuelsforthesamepurpose.
25
(GeothermalGenius,2015)
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
17
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UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
20
AppendixA
APPENDIXA:IllustrationsofGeothermalPowerTechnologyTypes
Illustrationsof
GeothermalPower
TechnologyTypes
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
21
Figure1:DrySteamPowerPlantConfiguration26
Figure2:SingleFlashSteamConfiguration27
26(Kagel,2008)
27Ibid.
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
22
Figure3:BinaryPowerPlantConfiguration28
28Ibid.
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
23
AppendixB
APPENDIXB:State-SpecificGeothermalPotential
Arizona
California
Colorado
Idaho
Montana
Nevada
NewMexico
State-Specific
Geothermal
Potential
Oregon
Utah
FactsheetSources:ElectricityandDirectUse
(EnergyInformationAdministration,2015c)
(Williams,Reed,Mariner,DeAngelo,&Galanis,
2008)
(EnergyInformationAdministration,2015a)
(EnergyInformationAdministration,2015c)
(USEPA,2015)
(NationalRenewableEnergyLaboratory,2015)
(ESRI,2014)
(Meldrum,Nettles-Anderson,Heath,&Macknick,
2013)–Forlifecyclewaterchartsinapplicable
states
FactsheetSources:HeatPumps
(EnergyInformationAdministration,2015c)
(EnergyInformationAdministration,2015e)
(EnergyInformationAdministration,2015b)
(EnergyInformationAdministration,2015d)
UsingGeothermalTechnologytoComplywithEPA’sCleanPowerPlan
24