A coal-fired power plant in Oklahoma is developing a 400 MW combined-cycle gas-fired unit to partly replace the 490 MW capacity of Unit 1, while retrofitting Unit 2 as a clean coal plant.
Grand River Dam Authority’s (GRDA) coal-fired power plant has a total output of 1010 MW. This currently meets 70% of GRDA’s generation requirement. By adding a gas-fired plant in replacement of Unit 1, the US utility company will boost the share of its gas from 25% to 45% total capacity.
The announcement follows a board meeting in which the board voted to proceed with the plan to marry gas with clean coal-fired power at the power plant.
Responding to regulations
Grand River Dam Authority (GRDA) is forging ahead with the combined gas and clean coal power plant, partly in response to new regulations proposed by the Obama administration, which could potentially limit the viability of coal-fired power plants. Dan Sullivan, CEO at GRDA, said “We do have some very real deadlines ahead of us in regards to [Environmental Protection Agency] regulations and customer demands.”
"This resource mix really gives GRDA the options it needs to maintain reliability and efficiently, and that's in the best interest of our ratepayers," said Sullivan.
Investment in renewables
GRDA also foresees increasing its wind power capacity by 3% to reach 13% of its total energy requirement. The utility operates three hydroelectric facilities and two reservoirs in Oklahoma and says its hydroelectric output will not change in the new generation mix.
Environmental upgrades of GRDA's coal-fired complex
The 490 MW Unit 1 of GRDA's coal-fired power plant complex was commissioned in 1982, while the 520 MW coal-fired Unit 2 was subsequently commissioned in 1985. Since then, Unit 1 and Unit 2 were dispatched for baseload electricity supply and have provided about 45% of GRDA's generation requirement, although volumes are set to drop about 17% following the retirement of Unit 1.
Clean coal upgrade
Unit 2 of the coal-fired plant will remain operational after being retrofitted with scrubbers that remove sulfur from flue gas emissions – the only one in the state, the utility said.
To comply with emissions requirements outlined in the EPA's Mercury and Air Toxics Standards (MATS), effective in April 2016, GRDA will retrofit some of the existing air quality control equipment.
Retrofitting works are scheduled to be completed by December 2015.
Edited from various sources by Sam Dodson
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