Coal is believed to be the most abundant fossil fuel on the planet, though it is still a finite resource. If current rates of production and consumption remain constant, it is estimated that the world's known coal reserves could last until around the 2120s.
However, coal's abundance comes with a high environmental overhead, and the UK Government has decided that any new coal-fired power stations must incorporate carbon capture and storage (CCS) technology to reduce their contribution to climate change. Until CCS is proven to work on an industrial scale, this effectively means no new coal-fired power stations can be built in the UK.
These are the quantity of supply challenges facing coal. Read about the possible solutions.