Texas muni to shut Gibbons Creek coal plant for most of the year
In ERCOT, the absence of a capacity market means energy market prices can reach up to $9000/MWh during peak demand events, making it profitable to operate some plants for only part of the year.
But a recent influx of wind generation is cutting down on the frequency of those episodes, and better economywide efficiency is denting overall demand growth. Despite occasional price spikes from hot weather, ERCOT says the Texas grid has sufficient capacity to meet summer loads. Total generation is about 82,000 MW, against a summer peak demand forecast of about 73,000 MW.
As renewables increase the need for fast-ramping generation, less flexible coal plants are running less. A report released last September by the Institute for Energy Economics and Financial Analysis showed average capacity factors for major ERCOT coal plants in 2015 were significantly lower than in previous years. Gibbons Creek was one, with Platts noting its factor dipped to 39% this year after averaging 86% between 2004 and 2008.
The IEEFA report found that coal generated 39% of the electricity in ERCOT in 2015, but only 24.8% as of May 2016. By 2031, ERCOT expects 10 GW of additional coal retirements as solar increases to 17% of its generation portfolio.