Green alternative energy

There are three alternative energy sources that leave no residue, are constantly renewable, and cause no problems: goethermal, wind, and solar. The others: biofuels, liberate vast amounts of carbon dioxide; nuclear, leaves toxic wastes. We need to fund massive research into the no residue energy sources, so they may be applied as widely as possible. It is also important to realize that just one energy source will no longer suffice.