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FORUM 2001 FORUM 2001

Parabolic Trough Developments for Concentrating Solar Power Markets

ESTABLISHING NEW BOUNDARIES

Ken MayPresidentIndustrial Solar Technology Corporation

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IST innovation has produced IST innovation has produced major cost reductionsmajor cost reductions

Figure 5: IST-PC System Costs

0

200

400

600

800

1000

1200

1400

1600

1980 1985 1990 1995 2000Year of Installation

Tota

l Ins

talle

d C

ost,

$/m

2 ($

2001

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DOE Program5,000

220

550

2700 1700700

10,000

Collector Area m2

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California California

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ArizonaArizona

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Status of US Trough IndustryStatus of US Trough Industry� IST is the only US company currently involved

in the manufacture and installation of PTC’s� Only US company to have installed PTC systems

since ~1984� Only US company that has exported PTC

systems in recent years� If not for IST, the US trough industry could have

“died” and tax-payer funded R&D efforts lost

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Next Phase of IST Product Next Phase of IST Product ImprovementImprovement

� Increased Production

� New Technology-USA Trough NREL/IST cost-shared development program-Phase II Developments

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Increased Production through Increased Production through Diversified MarketsDiversified Markets

� Utility Power MarketsSEECOTTM

CT inlet air coolingCT Steam Injection

ISCCS� Remote Power Markets--ORC� Process Heat Markets

Hot WaterSteam

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USA Trough :USA Trough : Addressing Limitations Addressing Limitations of Current Technologyof Current Technology

� Durability of plastic films� Reduced reflectance of films� Temperature limit of blackened nickel

selective surface� Obsolesce of system controller� Cost

Concentrator ~50% of system cost

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Elements of Development Elements of Development Program Program

• Glass/steel concentrator• Higher temperature and lower emittance

blackened nickel selective surface• System controller

• IST scopeComplete re-evaluation of system components: concentrator, supports, drive, receiver

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Concentrator MaterialConcentrator MaterialAluminum SteelAluminum Steel� Lightweight concentrator

5.4 kg/m2 � Corrosion resistant� Easy to work� Smooth surface for

reflective films� Advantages for low

production rates� Can use polished

aluminum reflector

� 17 kg/m2� Low cost� Stronger� More rigid� Easier, stronger

welds� Compatible with

glass� Reduced shading� Longer Rows

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Reflector MaterialReflector MaterialAluminized Film Silvered GlassAluminized Film Silvered Glass� Low cost� Easy to apply� Unbreakable

� Higher reflectance� Longer life� Compatible with

steel substrate� Scratch resistant

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Concentrator SubConcentrator Sub--TasksTasks

� Design and system evaluationComplete

� Procurement of materialsComplete

� Fabrication of test modulesCompletion in two weeks

� Structural testingIn preparation

� Deployment and field evaluation

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Results so farResults so far

� Glass mirror supplier working to improve product; testing by NREL and IST

� Design process has revealed many opportunities for cost reduction and performance enhancement

� Phase II: Increased aperture trough using IST structural concept

No apparent technical limitations

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Thermal Efficiency: Thermal Efficiency: Sandia DataSandia Data

Thermal Efficiency of IST-PC and LS-2

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0 50 100 150 200 250 300 350

Collector Temperature above Ambient, C

Ther

mal

Effi

cien

cy, % LS-2

IST-PC

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Needed Improvements of Needed Improvements of AbsorberAbsorber

� Higher temperature rating� Lower emittance at elevated temperature

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Improvement TechniquesImprovement Techniques

� Lower emittance substrateStainless steelPolished: mechanical or electropolished

� Higher temperature capabilitySol-gel barrier coat

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Improved Absorber SubImproved Absorber Sub--Tasks: Tasks: Joint IST/Sandia/NREL ProjectJoint IST/Sandia/NREL Project� Experimental matrix: Sandia/IST

Complete� Substrate preparation: Sandia� Application of blackened nickel selective

surface: IST awaiting samples� Application of barrier coat: Sandia� Measurement and evaluation:

Sandia/IST/NREL

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New System Controller New System Controller FeaturesFeatures

� Enhanced computational capabilities� Improved tracking accuracy� Position indication� Data acquisition, communication and

remote control functions� Improved reliability for unattended

operations

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TasksTasks� Design system logic

Complete� Write controller software

Ready for evaluation� Fabricate hardware interfaces

Underway� Field evaluation

Starting within ~one month� Test and Debug

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ISTIST--RMT (Roof Mounted Trough) RMT (Roof Mounted Trough) Initial Controller Test BedInitial Controller Test Bed

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SummarySummary� Project progressing rapidly� Prospects for significant cost improvement and

performance increase� Potential for short-term market deployment in

US with significant opportunity for exports� Maintaining US leadership in PTC technology� Entry to Phase II: Installation goal ~$100/m2