Testing PV in Israel's Arava Valley

While advocating for political change both locally and in Tel Aviv, Arava Power is also working with students and faculty at the Arava Institute of Desert Studies — a Kibbutz Ketura resident organization — to gear up for its anticipated project launch.

Conventional silicon and thin-film PV panels with and without solar tracking devices are being tested in the field along with solar concentrators to find out what yields the greatest generating efficiency in the particularly harsh and demanding environmental conditions found locally, where high ambient temperatures, along with wind-driven sand and dust, can pose difficulties.

"We're technologically agnostic — it just has to work for our business plan and in our environment and it has to be a stable long-term supply," Yosef Abramowitz, a transplanted Bostonian and former media company head who is now Arava Power's president said during a tour of the small testing area outside the Arava Institute of Desert Studies' administrative center.

Companies sell solar panels (mono or polycrystalline) with 20-year certifications but performance is based on optimal atmospheric conditions of 25 degrees Centigrade. Average temperatures at APC's site are far above that and performance (typically with 15% efficiency ratings, meaning that 15% of the sunlight directly hitting the panel will be converted to electricity) degrades a small percentage with every degree above 25.

Some of the test results have been very encouraging, however, Abramowitz said. APC is getting 28% above one manufacturer's claims for its conventional solar PV panels while Arava's researchers are recording a 7% boost in output from thin-film panels without tracking devices, and a 19% boost with them.

Thin-film PV hasn't been the favorite of solar power producers in Europe and the U.S. due to its relatively low efficiency — typically around 6% — but it offers advantages for APC in the Arava Valley, Abramowitz pointed out.

Located in a relatively sparsely populated desert region with large areas of unoccupied, unused land, space isn't as tight a constraint for Arava as it is more generally speaking in terms of acquiring land and zoning rights. As it happens, Kibbutz Ketura, the planned site, had previously obtained the requisite industrial zoning classifications for APC's initial 20 square-acre site and is in the process of doing the same for a larger 200 square-acre parcel of land it owns.

Solar concentrators are also being tested. Arava Power has a Letter of Intent with a solar concentrator systems vendor in California and is expecting to sign one or two others in the near future.

High local temperatures tend to degrade the performance of concentrators to an even greater degree than is the case for the crystalline silicon and thin-film panels, however, to the point where the PV cells are in danger of melting, according to Abramowitz.

That and the fact that manufacturers have not yet obtained certified 20-year equipment guarantees — which makes banks and investors balk at financing them — means that APC will move briskly out of the gate installing thin-film PV panels on its "proof-of-concept" solar mini-farm should the PUA increase the feed-in tariff rate structure and revise its solar power development program to allow kibbutzim and other collective communities the right to participate in it on an equal basis. The "proof of concept" plan is for a 2-4 MW grid-connected solar mini-farm on approximately 20 square acres of scrub and desert at the fringes of Kibbutz Ketura.

Arava Power figures it can generate electricity at roughly US $5 per watt installed with thin-film PV as compared to US $8-10 per watt with crystalline silicon panels, "which means we don't need as high a feed-in tariff, say, as in European countries," Abramowitz stated. "If in the next week the PUA includes kibbutz members equally in the Solar PV proposal at IS2.04 (US $0.58), we'll have bulldozers here by May 1 preparing the first field."

Andrew Burger is a RenewableEnergyWorld.com International Correspondent currently working out of Israel.