Besides oil being used for our energy needs, we have coal, natural gas, nuclear, oil shale, and tar sands. which type or types of energy will be used in the next 20 years? name which one/ones and give a detailed explanation of why you feel they will be used.

While i hope wind or solar power. if overpopulation continues we may very well have an energy source in people. Consider a man, condemned for an extremely terrible crime, murder, treason etc. maybe he could work  in manual energy creation, like them electric bikes (impractical on large scale but imagine possibly hundred of people.) and maybe they do more work, maybe they are seen as fit for society. But here's the kicker, humans, like other organic matter contains carbon. we've been using carbon like coal for ages. why not undesirable people who pose no purpose to the world. of course prisons would let the people pass of natural causes. but it would be a renewable recourse, that i believe is a fitting fate for the people previously mentioned. do share your opinion on the matter please.