Coal plants in the SPP used like natural gas plants in other regions
by September 26, 2018 11:09 am 513 views
Coal, natural gas and wind are the fuels that account for the majority of electricity generation in the Southwest Power Pool (SPP), a Little Rock-based regional transmission organization that covers all or part of fourteen Midwestern states, according to the U.S. Energy Information Administration. In the SPP, several states produce more electricity with wind than other states in the country, and coal-fired plants are operated similarly to natural gas plants in other regions to compensate for fluctuations in wind generation throughout the day.
Some plants in the SPP operate regardless of whether market prices will cover the plant’s marginal costs, and these are known as self-committed generators. Wind turbines, nuclear power plants and most hydroelectric generators are typically self-committed. Natural gas plants are more often driven by market prices, and these plants are referred to as market-committed generators.
Coal-fired plants, which account for the most generating capacity in the SPP, have several units that run on self-committed and market-committed schedules. These plants might operate on a self-committed schedule to fulfill contracts or because lower natural gas prices might prevent them from covering their marginal costs. In 2017, coal-fired plants operating on a self-committed schedule accounted for 82% of coal-fired electricity generation in the SPP.
The self-committed plants that operate on varying generation levels throughout the day might be doing this in response to changes in generation levels from wind generators, which change based on existing wind speed. Generation levels also change across seasons and reflect variations in electricity demand and wind. In this way, the self-committed coal plants in the SPP operate similarly to natural gas plants. In other regions served by regional transmission organizations or Independent System Operators, generation levels of natural gas plants are changed while coal-fired generation levels usually remain constant.