The microbes in the biodigesters are able to extract quite a bit of energy from the solids and convert it to a form usable by us humans – methane, which is used to generate electricity. Even though the microbes are quite efficient, there is still energy stored in the solid leftovers. The solids are first completely dried by the sun, and are then are transported to an offsite facility to become compost. This enriching compost adds nutrients to soil used to grow all sorts of things. This hearty material continues in the biological life cycle and eventually repeats the process again and again.