Oil accounts for the biggest share of global energy consumption today, followed by coal and, closely, by natural gas.

Firing can be by either coal or oil.

It is hoped that in the next few decades the overall efficiency of electricity production by brown coal can be increased to 50%.

The water available to the residents of Khewra had been polluted by salt, coal and other nearby mining activity.

China may manage to delay its fall by burning coal, but the present economic system has no long term future.

"Pipes of water heated by coal in the floor and the walls," he told Glennys solemnly.

Our village had no gas supply at the time and hot water and heating was all by coal.

The most popular way to make steam is to heat water by burning coal.

How much of this is down to more generation being by nuclear rather than coal and gas over the last couple of years?

Heating was by coal, with the coal being stored under the staircase.