Coal is considered low-cost in that to build a coal fired power plant, extract coal from the ground and to burn it does not cost a company as much as other fuel processes (because of the externalities that it ignores).
Coal is also plentiful; there is a large reserve globally.
This has lead to the people burning a lot of coal for centuries, which we continue to do today.
Coal has been used as an energy source for nearly 2000 years.
For example, it was widely used for home heating in early 17th century England.
But the Industrial Revolution dramatically increased the demand for coal.
Specifically, James Watt's improvements to the steam engine made coal useful for doing work.
Coal mining
- Strip mining: This method allows for the extraction of 60% of the worlds coal in the present time. A thin upper layer of rock (usually just a few 10's of meters) is removed to expose coal reservoirs 50-100 meters thick. These reservoirs of coal are referred to as coal seams.
- Mountain top mining: The top 300 or so meters of a coal containing mountain is removed via explosives to expose coal reservoirs 50-100 meters thick. Once the coal is extracted the excess rubble is deposited in nearby valleys.
Coal mining presents serious health risks to the miners directly involved.
These risks include black lung and coal worker's pneumoconiosis disease, which are caused by long term exposure to coal dust.
These risks include black lung and coal worker's pneumoconiosis disease, which are caused by long term exposure to coal dust.
Aside from human health effects, coal mining presents serious consequences for the environment.
The burial of streams, alterations to natural water flows, water pollution, additional erosion, and acid run-offs to surface waters are just some of the potential effects.
The burial of streams, alterations to natural water flows, water pollution, additional erosion, and acid run-offs to surface waters are just some of the potential effects.
Emissions
Like all fossil fuels, coal emits carbon dioxide when it is burned.
In fact, coal is responsible for more historical emissions of carbon dioxide than any other fuel.
Additionally, most coal also contains large amounts of other elements, like sulfur, mercury, and sometimes lithium.
Burning coal also causes the formation of both NOx and SOx.