The world is currently faced with energy challenges: oil reserves are being depleted at an unprecedented rate and depending on which statistic you use, we could run out of gas (literally) within the next 100 years. Renewable sources are not enough or difficult to harness. Nuclear power is extremely tricky to play with and the repercussions of misuse can last for generations. Cold fusion is currently the stuff of science fiction. We are living on borrowed times.
Apart from major hydroelectric schemes (Itaipu, Three Gorges, Aswan, Hoover, etc.) most of electricity consumed are made from turbines. Water is heated to super critical temperature and pressurized. The resultant steam is used to drive big turbines that produce electricity for use by industry and consumers. So, the biggest need for a power generation system is a sustainable heat source.
Currently controlled nuclear reaction, burning of gas and other fossil fuels, burning of coal, etc. produce the required heat.
The other major challenge posed by power generation has been the dangerous environmental after taste. The sourcing of the required input (oil, coal) and the running of these stations (nuclear waste, carbon dioxide, acid rain) have exposed everyone in the world to an impending climate disaster. So, there is also a need to balance out these effects by looking for green energy sources. That is where we ran into a brick wall. There are no green and realistic sources of energy. Solar panels are very expensive, and the efficiency is still at the very low levels. Cold fusion is still a technical mirage. Harnessing the ocean waves have been disappointing.
But what about digging deep?
Basic geography shows that the deeper you dig into the earth the hotter is becomes (and the more pressure too). Some measure it as .7 degree centigrade per every mile journeyed downward. The idea is this, what if we dig deep enough to reach a very high temperature and instead of using water, we could create some synthetic fluid with specialized features such as low boiling point whose vapor has the required pressure characteristics. All we need do is pump such fluid into the ground, get it heated up and it comes back up as highly pressurized gas which can be used to drive turbines for electricity production. At least there is a never ending supply of heat.
It sounds simplistic albeit it is probably packed with enough complexity to make scientists think rocket science is junior level arithmetic. However, the whole idea is to look inward to the unending (basically) power stored in the earth crust. If this can be achieved, the concept of energy generation would change forever. Cheap energy should put 100% electric vehicles on the road and if technology comes to the rescue, we could even have batteries that could charge fully in 5 minutes.