photosynthesis means producers convert from carbon dioxide, water, and solar energy into food for themselves. Scientists are experimenting to develop microbes that can live off surplus electricity and CO2 to produce ['organic products, such as methane, acetate and butanol as economic biofuels', 'less electricity and more CO2', 'solar energy and biofuels in the laboratory', 'fewer biofuels like butanol and less CO2']