CRADA Report

NREL/TP-7A1-48419 

August 2010

SkyFuel Parabolic Trough Optical 

Efficiency Testing

Cooperative Research and Development 

Final Report

CRADA Number: CRD-08-00266

NREL Technical Contact: Keith Gawlik
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Cooperative Research and Development Final Report

In accordance with Requirements set forth in Article XI.A(3) of the CRADA document, this document is 

the final CRADA report, including a list of Subject Inventions, to be forwarded to the Office of Science

and Technical Information as part of the commitment to the public to demonstrate results of federally 

funded research.

CRADA number: CRD-08-00266

CRADA Title: SkyFuel Parabolic Trough Optical Efficiency Testing

Parties to the Agreement: SkyFuel, Inc. – SkyWorks R&D + NREL

Joint Work Statement Funding Table showing DOE commitment:

Estimated Costs NREL 

Shared Resources

Equipment Value $ 10,000

Technical Support $ 40,000

TOTALS $ 50,000

Abstract of CRADA work: 

SkyFuel and NREL collaborated on the method of mounting SkyFuel’s parabolic trough(s) on NREL’s 

existing two-axis tracker system at SIMTA. NREL will made available to SkyFuel existing mounting 

components from previous trough tests.. SkyFuel delivered their parabolic trough ready for mounting 

on NREL’s tracker, using new and used mounting components. SkyFuel provided appropriate fluid 

connections on their trough’s receiver tube to mate to NREL’s coolant supply and return hoses. SkyFuel 

provided a crane service, approved by NREL ESH&Q, that placed and fastened the trough to NREL’s 

tracker, which the work plan was approved by NREL ESH&Q. NREL performed testing of SkyFuel’s 

trough in collaboration with SkyFuel. The testing occurred over a period of a number of months that

captured the effect of varying weather conditions on performance. At the end of the test program, 

SkyFuel coordinated with NREL to remove their trough and return NREL’s mounting components. 

Summary of Research Results: 

Tested parabolic trough products provided by SkyFuel, a manufacturer of parabolic trough systems in 

the concentrating solar thermal power industry. The testing evaluated the performance of the system 

at the Optical Efficiency Test Loop at Solar Industrial Mesa Top Area. The trough(s) were mounted on a 
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two-axis tracker and the receiver tube was supplied with coolant at near ambient temperature. The 

heat gain of the coolant was compared to the direct normal incident solar radiation that determined 

efficiency of the trough system at low temperature. The measured optical efficiency was between 77 

and 78%, a very high level and among the highest efficiency levels recorded in the parabolic trough solar 

industry.

Subject Inventions listing: None.

Report Date: 4/30/10 Responsible Technical Contact at Alliance/NREL: Gawlik, Keith

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