The addition to quantum dots to solar cells could lead to a tripling in efficiency, boosting from the usual 10% up to 40% or 60% (with concentrators). Silicon nanocrystals (quantum dots) are able to extract two or three electrons for each incoming photon, an unprecedented feat. Although solar is often hailed as a great, environmentally friendly energy source, it has a ways to go before being able to compete with fossil fuels - but efforts like this could make the difference.