Thin film solar cell production breakthrough
May 15, 2008 Advancing a viable market for photovoltaic solar energy involves a balancing act between creating efficient solar cells and at the same time reducing the cost of the manufacturing process. Solar efficiency has been demonstrated to levels as high as 22% (a record set by SANYO last year), and although HelioVolt Corporation's latest announcements concern technology that is only delivering 12.2% conversion, the company has made great strides on the other side of the equation. Its proprietary FASST reactive transfer printing process has produced solar cells in a record setting six minutes, according to HelioVolt that's 10 to 100 times faster than current production of thin-film photovoltaics and could lead to manufacturing costs of less than $1 per watt.
Unlike the Sanyo crystalline silicon-style cells, the HelioVolt cells uses thin film technology based on Copper Indium Gallium Selenide (CIGS). It's worth noting that the solar conversion comparison - basically a ratio of the energy produced and the amount of sunlight hitting the surface of the cell - isn't exactly "apples and apples", and the 12.2% achieved by HelioVolt’s device is very efficient for thin film technology.
CIGS which offers significant cost savings for solar electricity installations by reducing the amount of material required to produce electricity from the sun, along with durability, a life-span equivalent to silicon and the ability to be manufactured in a printing process.
This last attribute means the FASST process can be used to print high efficiency, low-cost thin film material directly on glass substrates for solar modules OR onto an array of building products including steel, metal, glass and roofing tiles where it can be integrated into architecture as a type of "solar skin".
The company says the cost of less than $1 per watt that it is targeting with its thin film technology is, according to a study conducted by the U.S. National Renewable Energy Laboratory, the price point at which the photovoltaic market can compete with fossil fuels.
Dr. BJ Stanbery, CEO and founder of HelioVolt said that CIGS was already achieving the highest efficiencies of any thin film solar material in the lab. “The challenge of course is transferring that efficiency to a high throughput, high yield, low cost process capable of delivering gigawatts worth of quality commercial product,” he said.