Fertilizer Waste to Solar Panels: Too Good to be True?

By Adam Brock

Solar power is often seen as the great unrealized hope of renewable energy. While wind and biofuels are now serious economic contenders, solar power always seems to be on the verge of some breakthrough or another that will make it cost-competitive – and yet it remains as expensive as ever. With enough government support, it’s likely that some of these “wonder processes” actually would make solar viable, but as it stands, the numbers just don’t work.

Oil Drum yesterday posted a fascinating look at one of these wonder processes – one that uses a waste material, to boot. Engineer-poet, the post’s author, explains that the silicon for most of today’s PV panels is manufactured using a costly process that was developed for semiconductors. But a number of techniques have been developed recently to utilize silicon that’s in a less pure state. Evergreen Solar has been working on one such process, which makes silicon ribbons “directly from a molten silicon bath”.

Meanwhile, raw silicon has been piling up for years as a byproduct of phosphorous mining for fertilizer production. Engineer-Poet proposes applying Evergreen’s process to this stockpile, which, according to his calculations, would be able to generate 48 gigawatts of power every year. “For the rough price of 1 year of the war in Iraq,” he writes, “we could make peak PV generation equal to about half of the nameplate capacity of every generator on the US grid.”

Is the age of cheap solar power finally upon us, or is Engineer-Poet’s solution the latest flash in the PV pan? Decide for yourself… I’m gonna go take a molten silicon bath.