Making Solar Power Cheaper, Smaller, Easier

Thanks to pioneering work at NREL, solar power manufacturer Amonix is now delivering commercially-ready, concentrated PV solar power “screens” that deliver 600 times as much electricity per square foot as standard solar PV panels.

NREL is the National Renewable Energy Laboratory, one of over a dozen research facilities owned and managed by the U.S. Department of Energy. One of NREL’s developments was highly efficient, multi-junction PV cells made from indium gallium arsenide (InGaAs) and  gallium phosphide (GaP).

Amonix took NREL’s work and went several steps further, replacing the gallium mixes with silicon (thanks to a NREL grant for $1.2 million), and using acrylic rather than glass Fresnel lenses to concentrate sunlight.

In the end, laboratory cells that converted 41.6 percent of solar insolation to energy ended up achieving only 31 percent efficiency (for individual modules) and 27 percent (in a field system).

Even so, a typical Amonix 7700 system, measuring 77 feet wide and 49 feet high, produces 50 percent more electricity than earlier generations of Amonix solar cells, and a the 7700 model (a 53-kilowatt system) – by integrating lenses, cells and mounting unit into a single element, thus eliminating costly parts and installation time – can be transported on two flatbed trucks to the field, then assembled in hours rather than days.

The joint NREL project began in 2004 and ended in 2008. At that time, Amonix was able to demonstrate 31-percent efficiency for a square-meter panel, or module (about 10.76 square feet) – a world record at the time.

Even today, the conversion rate remains significant, both in terms of rated power and in terms of the amount of land needed to generate it. For example, 20 7700 units, on five acres, can create enough electricity to serve 750 homes. A typical PV solar field would need 35 acres to generate the same amount of energy.

Of course, Amonix is only one of many U.S. solar innovators and manufacturers working to bring the cost of solar energy down to where it meets, or even exceeds, grid parity, or about $1 per watt, or $0.06 per kilowatt-hour of electricity.

In order to do that, prices have to come down as much as 75 percent from today. But SRI Consulting recently issued a report showing that reduction of costs of system components (inverters and the like) has put solar energy closer to grid parity at utility scale, and as improvements continue to be made, “the world is likely to see an environment where PV subsidies are no longer necessary (to promote solar energy uptake).”