That light barreling down upon us from the end of the tunnel is solar power as cheap as fossil fuels. The latest breakthrough is a low-cost solar cell manufactured with the help of Gallium Arsenide, a compound of the “poor metal” gallium and arsenic.
It definitely does not sound like something you’d want to eat, but a recent laboratory demonstration shows that the resulting solar cells have the potential to produce electricity at a cost as low as 45 cents per watt, far below the grid standard of $1 per watt.
Another Road to Cheap Solar Power
The breakthrough comes courtesy of New Jersey–based Global Photonic Energy Corporation (GPEC) and its research partner, Dr. Stephen R. Forrest, Vice President for Research at the University of Michigan.
The new thin-film solar cell is based on organic photovoltaic (OPV) technology that uses carbon (conventional solar cells use silicon).
Engineering a more efficient solar cell is one key to cutting costs, but commercial-scale manufacturing plays another critical role in the overall cost of solar power. Greater efficiency does not necessarily march in lockstep with lower manufacturing costs, so the trick is to find a balance between the two.
That’s where the partners concentrated their research. The result is a new low-cost manufacturing process that involves using one Gallium Arsenide wafer to produce many solar cells.
Gallium Arsenide is used in conventional solar cell manufacturing, but until that process involves using the same wafer only once or twice, which puts a significant drag on manufacturing costs.
We Built This!
Solar cell efficiency is still a key part of the equation, and this is where GPEC’s decades-long research into “small-molecule” systems has come into play.
However, translating that efficiency into marketable products involves a different skill set, and that’s where the University of Michigan came in. Last year, Dr. Forrest won a grant of $1.5 million from the U.S. Department of Energy to incorporate GPEC’s propriety molecules into a “stacked architecture” that combines high efficiency and high reliability with low-cost manufacturing.
The grant was awarded through President Obama’s SunShot Initiative, which launched last year with the mission of bringing the cost of solar power down to fossil fuel parity within a few years.
Part of SunShot involves support for new, high-efficiency solar cells, including organic solar cells.
SunShot also places a heavy emphasis on reducing the “soft costs” of solar power (installation, permits, grid connections, etc), which DOE estimates can account for about half the overall cost of a solar array.
Location, Location, Location
Speaking of soft costs, when you talk about the installed cost of solar power, it’s also important to account for how it will be used. In the case of GPEC, the new flexible sheets seem to be aimed initially at the market for mobile and off-grid locations, including military equipment and satellites, where installation issues and other soft costs are quite different from those involved in the solar power market for buildings and other permanent structures.
However, the company also has a broader market in mind. Aside from layering the new solar cells onto plastic sheets, GPEC is looking at building-integrated applications such as spray-on solar “paint” and transparent solar windows. The company also envisions using the new technology for solar vehicle paint, solar covers for recharging portable electronics, and solar fabric.
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Tina Casey specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. You can also follow her on Twitter @TinaMCasey and Google+.