Coal is abundant in many parts of the world but mining it is hazardous and costs a lot of money. Could the answer be to burn it in the depths of the earth and syphon off the gasto create electricity?

摘要

A worldwide requirement for new energy sources means that unconventional technologies first trialled long ago are now being resurrected with a renewed sense of vigour and expectation. That is certainly the case for underground coal gasification, a highly promising but undoubtedly controversial method of burning coal in-situ, typically several hundred metres beneath the surface, to produce a synthetic gas that can be used to produce electricity and for other industrial purposes. Underground coal gasification has been touted for decades as a viable means of deriving energy from the billions of tonnes of unspent coal reserves around the world. But only now are there serious efforts to prove the technology on a truly commercial scale.