Scientist suggests large-scale CPV program in US

An advanced solar cell researcher with over 25 years at Boeing, Chevron Research, and Hughes Research Labs, and now with small company JX Crystals, Lewis Fraas is among a class of scientists who have gone from developing high power cells for space applications to bringing them down to earth.

© JX Crystals Inc. Concentration for peace: A book filled with solar industry ironies, insights and ingredients for becoming a major source of electricity in the 21st century.

»Why is there still no commercial 35 percent cell?« asks Lewis Fraas, president of the small Issaquah, Washington-based company JX Crystals in the revised 2005 edition of his 143-page book Path to Affordable Electric Power & the 35 percent Efficient Solar Cell, first published in 2003. Fraas, a veteran solar scientist who claims that his Boeing High Technology Center research team first demonstrated a 35-percent efficient multi-junction cell in 1989, answers this question in engaging technical detail and proposes both political and technical solutions.

Provocative and ambitious, the book is meant for both technical and non-technical readers »who believe that resolving our energy problems at home is preferable to present and future wars over oil and natural gas.« One of the strongest messages of the book is that highly efficient multi-junction cells (approaching 40 percent) packaged into solar concentrator systems can play a central role in the energy future of the United States – if the US commits funding to prototype integration, qualification testing and manufacturing scale-up. 

One reason this technology has been delayed, argues Fraas, is that the US has spent over 80 percent of its R&D dollars for solar energy in the past 25 years on thin-film solar cells to chase the dream of a 20-percent efficient low-cost cell. »A very attractive dream,« says Fraas, who argues, however, that it is not well-founded on scientific principles.

Another reason is the lack of performance and reliability track records for concentrator systems designed for the utility-scale market. Happily, he notes that Australia-based Solar Systems and California-headquartered Amonix are now providing this. Cost, of course, remains a barrier – but one that is showing cracks with increasing production volumes (see PI 7/2005, p. 50). 

Amonix, together with joint venture partner Guascor Group of Spain, now is making a run at solving this chicken-and-egg conundrum, and cost reductions may be imminent. Arizona Public Service, which has installed over 500 kW of the Amonix concentrator system with mid-20-percent efficiency silicon cells, cites an installation cost of $6 per W, but believes that at a volume of only 5 to 10 MW a year the cost of installation can drop to under $4 per W. According to Fraas, that can even decrease to under $2 per W with 35-percent efficient solar cells at 10 MW annual production, or about 6¢ per kWh.

Companies such as JX Crystals will avert the »high-cost low-volume predicament« by developing low-concentration mirror modules for niche uses, says Fraas. Incidentally, in April 2005, JX Crystals signed a contract with Chinese officials in Shanghai for a 100 kW demonstration of a 3 × mirror module using SunPower A300 silicon-based cells cut into thirds. By cutting the modules into thirds »you can triple production with no new factory,« says Fraas, without losing hardly any efficiency in the SunPower cell.

Looking forward to a 40-percent efficient cell, Fraas describes in the book's updated version new work by JX Crystals and SRS Engineering & Agencies Ltd. of Israel on a »Cassegrain« PV module with a target of 33-percent efficiency using hybrid multi-junction cells. The design splits the sun's spectrum into two cell locations using a secondary mirror and makes achieving near-ideal efficiencies for triple- and quadruple-junction cells practical at 47 percent and 52 percent, respectively.

In the end, the book is as political and personal as it is technical, starting with Fraas's refusal to submit a bid in Nov. 2004 for a smart munitions request to use JX Crystals' infrared sensitive cells for in-flight timing and fuse ignition. »When we invented this infrared solar cell, we never dreamed of this application,« he says, showing concern over how multi-junction solar cells are applied. »While peaceful applications have not been funded, the irony is that this technology is being used in weapon systems to liberate oil from the Middle East for the free world.«

The US should launch a serious national program for alternative energy and reset its moral direction, argues Fraas, whose intention for writing the book was to convince policymakers, investors and the public of the potential for high-concentration utility-scale PV and the need for a »much larger top-down commitment [possibly] in the billions of dollars« for solar energy.

Pointing to enormous national investments for nuclear energy, hydropower, and airline development, he asserts that private enterprise alone never would have led to commercialization of these key industries.

Unfortunately, Fraas believes the US moral compass on energy is now mired in a war over oil in Iraq. »Since we are not even discussing this problem, we are behaving like an addict in denial,« he concludes. »I pray that the American government will wake up and develop alternatives to oil so that our soldiers can come home. Who knows, maybe in the future they might have jobs building, marketing, or installing solar arrays around the world.« The provisions for solar in the recently passed US energy bill (see PI 9/2005, p. 44) might be at least a small step in this direction.

Path to Affordable Solar Electric 
Power & The 35 percent Efficient Solar Cell
Lewis Fraas
JX Crystals Inc., 2005
143 pages, paperback
$35
ISBN 0-9748530-0-3

Garrett Hering
© PHOTON International, September 2005