Technology Merit: Solar Power

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Amonix (Seal Beach, Calif.) for sprinting toward the front of the pack of firms seeking to develop and market concentrating photovoltaic (CPV) systems that use lenses to concentrate sunlight on high-efficiency PV cells to produce greater power output per square meter than conventional PV modules. In August, 2010, project developer Cogentrix announced a 20-year power purchase agreement with Xcel subsidiary Arizona Public Service for a 30 MW CPV project in Alamosa, Colo., using Amonix's equipment. If it meets the developers' target for commercial operation in 2012, Alamosa will be the largest CPV installation in the world.

"Currently the largest one in operation in the U.S. is a 1MW CPV project just completed by SolFocus" in 2010], wrote Ucilia Wang on GigaOm.com. SolFocus is also building a 10 MW CPV project in Spain, according to Wang. Amonix had previous deals to supply its CPV systems to an "undisclosed developer for two projects [totaling 14 MW to supply] Tucson Electric Power under power purchase agreements," according to Wang. Then, in November 2010, Southern California Edison signed PPA contracts for 28.5 MW of Amonix CPV capacity at four sites in California that are expected to come online in 2013 and 2014.

Amonix, founded in 1989, also celebrated some financing milestones in 2010. In April it received $129.4 million in a Series B financing round from Kleiner, Perkins, Caufield & Byers, Adams Street Partners, Angeleno Group, PCG Clean Energy & Technology Fund, Vedanta Capital, New Silk Route, The Westly Group and prior investor MissionPoint Capital Partners. Amonix also received $9.5 million in ARRA stimulus funding under the Advanced Energy Manufacturing Tax Credit program to create a new manufacturing plant in North Las Vegas, which broke ground in October, and a future facility planned in Arizona.

SolarEdge (Hod Hasharon, Israel) for achieving prominence in an emerging segment of PV system components that maximizes output when one or more modules in a PV array-or cells in a module-underperform due to shading, inherent mismatches or premature degradation. According to an August 2009 Scientific American article by editor George Musser, power loss is multiplied with typical PV array configurations because inverters cannot optimize each module individually but need to select identical current to flow through all modules in the underperforming string.

Musser highlighted SolarEdge's technology to optimize the output of modules and arrays when a segment is compromised. National Semiconductor and other companies also market PV optimization gear, but SolarEdge's PowerBox solution has received significant industry notice, including a ranking in the top 10 energy companies (along with FirstSolar, PG&E and Nextera) for 2010 by tech magazine Fast Company. A comparison analysis of six vendors' optimization systems by the German edition of Photon Magazine called SolarEdge's system "mature, provid[ing] additional yield and ... one of the less expensive solutions," according to an excerpt provided by SolarEdge. "The PowerBox monitors the performance of each module for fault detection and remote troubleshooting over the Internet, and provides unique safety mechanisms that cut off voltage and current during installation and fire-fighting," according to SolarEdge, which says it has 30 pending patent applications and has shipped over 250,000 units in over 25 countries in 2010.

Cogenra (Mountain View, Calif.) for commercializing, at least on a limited basis, a solar energy system that makes use of both solar thermal and photovoltaic energy. The Khosla Ventures-funded startup installed its first large system in November 2010 at the Sonoma Wine Company in Graton, Calif., a contract winery that bottles more than 4 million cases a year. The winery installed 15 of Cogenra's SunBase arrays, which collectively produce 272 kW of electricity and solar hot water.

Calling its technology solar cogeneration (some in this emerging segment call it hybrid PV/thermal or PV/T), Cogenra says it improves system energy production by up to five times over PV-only systems. A story in MIT's Technology Review, describes the Cogenra system as consisting of 3 x 10 meter parabolic dishes that concentrate sunlight onto PV cells. "Heat is collected with a mixture of glycol and water that flows through an aluminum pipe behind the solar cells" then fed to a heat exchanger and hot water storage tank. "Similar hybrid solar systems have failed in the past because the solar cells have overheated. Cogenra uses sensors to monitor the temperature of its solar cells and an automated control system to draw fluid away more quickly if they need cooling down," according to Technology Review, which noted that Cogenra hasn't released cost figures and that the winery installation will serve as an important test site for Cogenra's technology and PV/T in general.