Cheaper Concentrating Solar For Photovoltaics

While the bulk of concentrating solar now in use is for solar thermal steam electric power generation it is not the only use of concentrating solar. Highly concentrated light shined on photovoltaic (PV) materials greatly lowers the amount of PV needed. If the concentrator costs less than PV for the same area then concentrator plus PV can be a cheaper way to go. A Canadian company, Morgan Solar, claims to have a better way to concentrate sunlight for PV solar.

A couple of years ago, Nicolas's brother John Paul Morgan came up with the idea of a solid-state solar concentrator system: a flat, thin acrylic optic that traps light and guides it toward its center. Embedded in the center of Morgan Solar's concentrator is a secondary, round optic made of glass. With a flat bottom and convex, mirrored top, the optic receives the incoming barrage of light at a concentration of about 50 suns and amplifies it to nearly 1,000 suns before bending the light through a 90-degree angle. Unlike other concentrators, the light doesn't leave the optic before striking a solar cell. Instead, a high-efficiency cell about the size of an infant's thumbnail is bonded directly to the center bottom of the glass optic, where it absorbs the downward-bent light. There's no air gap, and there's no chance of fragile components being knocked out of alignment.

They think they can compete with thin film solar on costs by 2011.

Some business and engineering decisions must still be made, but he expects that the company will be able to build its system for less than $1 per watt by 2011--"and with some vertical integration, considerably less." This would lead to a product close to 30 percent efficient at costs competitive with thin film.

FirstSolar is the market leader for low cost thin film photovoltaics. In Q1 2008 FirstSolar claimed a manufacturing cost of $1.14 per watt. They aren't sitting still. By 3Q 2008 they were claiming $1.08 per watt. Their cost will be even lower in 2 years time. Morgan Solar needs to come in under $1 per watt to compete.

Concentrating solar for PV is best used with higher priced PV that has higher conversion efficiencies. The higher cost for materials with higher conversion efficiency does not matter because the amount of PV used is very small. Concentrating solar's ability to compete might end up hinging on how much conversion efficiencies improve. A doubling of conversion efficiency would probably cut Morgan's cost in half. More than a doubling in PV conversion efficiency might be possible.

Update: First Solar claims a manufacturing cost below $1 per watt for 4Q 2008.

TEMPE, Ariz.--(BUSINESS WIRE)--Feb. 24, 2009-- First Solar, Inc. (Nasdaq: FSLR) today announced it reduced its manufacturing cost for solar modules in the fourth quarter to 98 cents per watt, breaking the $1 per watt price barrier. This achievement marks a milestone in the solar industrys evolution toward providing truly sustainable energy solutions, said Mike Ahearn, First Solar chief executive officer. First Solar is proud to be leading the way toward clean, affordable solar electricity as a viable alternative to fossil fuels.

First Solar has cut their cost by about 16% in less than a year. Impressive. Complaints that solar PV costs go down too slowly are starting to sound outdated.