In general, coal is considered to be the most abundant and geographically dispersed fossil fuel, and therefore to be a secure energy source.
However, the UK relies heavily on imported coal to fuel its coal-fired power stations. In 2009 about 78% of the UK energy industry's demand for steam coal – the kind burned in power stations – was met by imports. Relying too heavily on imports can leave countries vulnerable to fluctuating international market prices and disruptions to fuel supplies caused by geopolitical disturbances.
The UK imports coal from countries such as Russia, Colombia and the United States. The majority of this – about 56% of the UK's coal imports in 2009 – comes from Russia.
Only about 38% of the industry's demand for steam coal was met by the UK's domestic mines in 2009. This means that the country imported more than twice as much coal as it produced in this year. The 16% demand surplus is stockpiled.
The UK Coal Forum estimated the UK's underground coal reserves to be about 105 million tonnes in 2009. In addition to these underground reserves, there are surface-level coal fields, but mining these requires planning permission. However, it is typically less expensive to import coal than to mine it in the UK.
These are the security of supply challenges facing coal. Read about the possible solutions.