Fool's Gold could slash cost of solar power

Scientists at Berkeley have this week released research revealing that alternative raw materials, such as iron pyrite – or Fool's Gold – could offer a far cheaper alternative to silicon for solar panel manufacturers.

The rapid growth of the global solar market has been repeatedly hampered by shortages of silicon, which is used to make the semiconductors found in many solar panels.

But now Berkeley researchers have identified 23 promising semiconductors that could be used as an effective alternative to silicon. They concluded that 12 of the alternatives are more abundant than silicon, while nine would be cheaper to manufacture than silicon.

"We started looking at new materials because people often assume solar will be the dominant energy source of the future," said Cyrus Wadia of the Lawrence Berkeley National Laboratory, who led the research. " But current solar technology may not get us there in a time frame that is meaningful, if at all. We must turn our attention back to basic science research if we are to solve the problem."

Currently, the most viable commercial alternative to silicon-based solar panels are so-called thin film panels, typically made from cadmium telluride or copper indium gallium selenide (CIGS). However, critics claim that resources of these raw materials are not sufficient to support a genuinely global rollout of thin film solar panels.

Daniel Kammen, UC Berkeley professor of energy and resources, said that rather than focus solely on thin film and silicon-based solar cells, the industry had to continue to explore alternative approaches. "We believe in a portfolio of technologies and therefore continue to support the commercial development of all photovoltaic technologies," he said. "Yet what we have found is that some leading thin films may be difficult to scale as high as global electricity consumption."

Iron pyrite, copper sulphide and copper oxide were at the top of the list of potential silicon and thin film replacements, with iron pyrite – more commonly known as Fool's Gold – deemed the leading candidate in terms of both cost and abundance.

The research was supported by the US Environmental Protection Agency, the Energy Foundation, and the Karsten Family Foundation Endowment of the Renewable and Appropriate Energy Laboratory.