Photovoltaic solar cells have been part of renewable energy planning for as long as such planning has existed, with most of those solar cells made from crystalline silicon with energy conversion efficiencies above 20 percent. But crystalline cells are expensive and take a lot of energy to create, reducing their net energy contribution. Fortunately there are other types of solar cells including thin film, amorphous, plastic, and others. All of these are cheaper than crystalline cells though they also tend to have shorter working lives and lower efficiencies. We care about them, though, because organic plastic solar cells in particular offer the prospect of producing the cheapest electric power of all. That is if one […]