Coal plant shutdowns to lower power reserves

NRG Energy is outfitting its W.A. Parish power plant in Fort Bend County with new infrastructure to capture carbon dioxide from coal burned in one of the plant s generators instead of releasing it into the atmosphere. The new facility will pipe the greenhouse gas to an oil field for use underground in enhanced oil recovery. (NRG Energy photo) less NRG Energy is outfitting its W.A. Parish power plant in Fort Bend County with new infrastructure to capture carbon dioxide from coal burned in one of the plant s generators instead of releasing it into the ... more Photo: NRG Energy Photo: NRG Energy Image 1 of / 1 Caption Close Coal plant shutdowns to lower power reserves 1 / 1 Back to Gallery

The shutdown of three coal-fired and a natural gas plant will knock Texas' summer power reserves below the recommended level, according to a report released Monday by the Electric Reliability Council of Texas, which oversees 90 percent of the state's power grid.

ERCOT is charged with ensuring that Texas has enough power to meet demand on the hottest summer days, when electricity consumption peaks. In 2010, ERCOT in 2010 adopted guidelines calling for the grid's generating capacity to exceed demand by at least 13.75 percent.

The difference between generating capacity and demand is called the reserve margin.

ERCOT's forecasts for the summer of 2018 show that the reserve margin will fall to of 9.3 percent, down from earlier forecasts of more than 18 percent and well below ERCOT's recommended level. ERCOT said that fluctuations in reserve margins are not uncommon, and ERCOT's report noted that more power is expected to come online by 2019.

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Texas reached an all-time high for power demand in August 2016 and demand is expected to grow by nearly 2 percent every year for the next decade.

In a report released Monday, ERCOT attributed the drop in reserves to the eventual loss of more than 4,300 megawatts from three coal-fired power plants owned by Vistra Energy, Monticello, Sandow and Big Brown, and one natural gas plant. A loss of 1,143 megawatts in power from plants expected to have planned extended outages also contributed to the dip in reserve margins.

A megawatt is enough to power about 200 Texas homes on the hottest summer days.