Renewables, Solar

Concentrated PV cells bring solar power into realm of commercial viability

Issue 2 and Volume 99.

Concentrated PV cells bring solar power into realm of commercial viability

Integrated high-concentration photovoltaics (IHCPV) have achieved a solar conversion efficiency greater than 20 percent in a 2,000-W testbed array installed at Georgia Power Co.?s Shenandoah Environment & Education Center, near Atlanta, Ga. This potentially low-cost solar technology established a new world record for commercial-scale electrical energy conversion from sunlight.

OThis performance is significant because it establishes the viability of a technology that promises cost-effective electricity generation in a utility scale system,O said Dr. Edgar DeMeo, Electric Power Research Institute (EPRI) manager of renewable alliances. OHigh volume production will put IHCPV on the fast track toward cost-competitiveness with conventional electrical generation.O

AMONIX Inc., Torrance, Calif., built the system, and also recently shared a O1994 R&D 100 AwardO with EPRI and others for developing the advanced high-concentration solar cell that is the heart of the new solar device.

Unlike flat-plat solar modules using large areas of solar cells and operating at a fixed tilt toward the sun, the IHCPV system uses low-cost plastic concentrating lenses to track and focus sunlight into small-area solar cells. By concentrating sunlight 200-500 times, such systems can substantially reduce the amount of silicon cell material needed to generate a specific quantity of electricity.

OIHCPV technology is capable of meeting the cost goals set by utilities for a commercial solar energy system?$1.50 per watt of installed capacity or six cents per kilowatt hour of generated electricity,O said Vahan Garboushian, AMONIX president. OThe technology can be competitive now for rural electrification applications such as isolated villages in developing countries or high value distributed installation in this country.O

A 20-kW demonstration system is under construction for utility evaluation at Arizona Public Service?s Solar Test and Research facility in Tempe, Ariz. Additional utility test sites are planned this year.

Several technological breakthroughs over the past few years led to the current system. Earlier high-concentration cells suffered performance degradation after exposure to the sun, but today?s cells overcome the problem through radiation hardening developed for space satellites. Also, fabrication costs were reduced through an EPRI-patented design for creating Ointegrated arraysO of cells, concentrator lenses and array structure.

The integrated array structure was designed by Scientific Engineering Inc., Montgomery, Ala., which teamed with AMONIX for commercialization of IHCPV systems.