Materials to Scale Solar Power to Terawatt Levels

A new research paper evaluates material extraction costs and supply constraints for 23 promising semiconducting materials that could be used to afford ably scale solar power to terawatt levels. 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.

Greatly increased penetration of photovoltaics into global energy markets requires an expansion in attention from designs of high-performance to those that can deliver significantly lower cost per kilowatt-hour. Twelve composite materials systems were found to have the capacity to meet or exceed the annual worldwide electricity consumption of 17000 TWh, of which nine have the potential for a significant cost reduction over crystalline silicon. We identify a large material extraction cost (cents/watt) gap between leading thin film materials and a number of unconventional solar cell candidates including FeS2, CuO, and Zn3P2. We find that devices performing below 10% power conversion efficiencies deliver the same lifetime energy output as those above 20% when a 3/4 material reduction is achieved. Here, we develop a roadmap emphasizing low-cost alternatives that could become a dominant new approach for photovoltaics research and deployment.

Eric Drexler points out that Pyrite (FeS2) is one of the best materials for scaling solar power and Pyrite is also an excellent material for molecular nanotechnology.

Biological examples show that protein molecules can guide crystal growth by selectively binding to crystal surfaces and surface features, and pyrite can grow under conditions that are compatible not just with proteins, but with living organisms. Development of a good crystal-shaping molecular toolkit could provide a route to a useful class of atomically precise fabrication techniques, and pyrite is an attractive target.