Coal and U.S electric power generation

concentration of carbon, though other elements (such as sulfur, oxygen, nitrogen) remain in the coal.  This process resulted in the various types of coal seen today, which are ranked according to their moisture content and concentration of carbon.

USGS and coal
USGS has studied coal for more than 100 years. In addition to its own research, USGS works with others, predominantly state geological surveys, to provide the basic geologic information to assess the nation’s coal resources. The largest and most well-known areas of coal the USGS has assessed are the Appalachian Basin and Illinois Basin in the eastern U.S. and the Williston Basin, Colorado Plateau,  and the Powder River Basin in the western United States.

USGS also studies the environmental effects of developing and using coal, such as greenhouse gas emissions from underground coal fires, air quality impacts from coal utilization, and studying coal quality for fuel use optimization.

Optimizing fuel use and minimizing its impact on the environment are necessary components of twenty-first century strategies for meeting society’s energy needs. One critical aspect of fuel use optimization is an understanding of the geologic factors that affect fuel quality. For example, the composition of coal critically influences power generation efficiency, the impact of coal use on the environment, and the composition and usefulness of combustion products.

Coalbed gas
There is another important resource directly related to the Nation’s coal: coalbed gas. Generated in and produced from coal seams, coalbed gas, often called coalbed methane, accounts for approximately eight percent of the U.S. natural gas production and has many of the same uses as coal, such as production of electricity and fuel for our home furnaces during the winter. In addition, it can be used in fertilizers, or for transportation in place of gasoline, which is derived from oil.

In addition to its uses, coalbed gas can be a hazard as it could lead to suffocation and explosions (it is extremely flammable in combination with coal dust). Miners would bring canaries into the mines to help them know when large concentrations of methane were in the area.  In modern times, mine ventilation techniques and methane detection equipment has reduced the methane hazard for miners.

Coal is an important part of the U.S. energy mix, and the United States is richly endowed with coal. After all, the Powder River Basin is the largest deposit of low-sulfur subbituminous coal in the world. As the latest assessment of the Powder River Basin also shows, however, there is a significant difference between the in-place resources and the recoverable resources, let alone the economic resources. USGS says its coal research provides critical information for government and private managers to know just how much coal really is present, what is usable, and its quality.