A solar cell converts sunlight into electricity: most of those on the market are made of a material called silicone.
MIT researchers explore the promising qualities of spinach as an energy source capable of providing electricity: the solar cells made by them use proteins from spinach and a bacterium, the Rhodobacter sphaeroides.
2 billion proteins on a glass structure constitute a "biological" layer to be alternated with a semiconductor layer: the platform thus obtained allows the proteins to absorb light and "return" electrons which, through the semiconductor layer, produce an electric current.
In this first, promising phase of the research, the "spinach" cell is still inefficient: it will be necessary to increase the dose of proteins present on the platform, and keep them "alive" for a longer time. The goal is to obtain solar cells capable of self-repairing and renewing themselves, just like plants.
One day we could literally "cultivate" our energy by watering and feeding our biological solar cells.