Sweetwater, TX coal plant gets the EDF ‘thumbs up’
Yesterday, EDF and Tenaska Inc. signed an agreement that ensures that EDF will not stand in the way of the facility’s permits as long as the plant meets conditions regarding air emissions and water use.
The agreement between EDF and Tenaska requires the new Trailblazer Energy Center to capture 85% of its carbon dioxide emissions, presumably through carbon capture and storage technology (CCS). This technology is a foundation in the clean coal concept, capturing these greenhouse gases before they are emitted into the air. The captured gas is then stored underground in existing geological formations or in huge tanks (a very unattractive and expensive option compared to underground geologic storage). This way, the gases don’t contribute to global climate change because they are not actually released in the air. CCS discussions normally revolve around a 90% capture rate, so the Trailblazer capture rate will be fairly aggressive.
The proposed coal power plant has also agreed to only obtain 2,000 acre-feet of water (about 657 million gallons) per year from “outside sources.” As CCS technology increases the water needs of an already thirsty coal power technology, this agreement is even more significant. A typical coal plant consumes 426 gallons of water per megawatt-hour of electricity that it generates. This means that, if the Trailblazer facility runs 80% of the time (typical for a Texas coal plant) it will use 1.7 billion gallons of water per year (this value is certainly higher with CCS technology). The Sweetwater plant will use a dry cooling system where air is used instead of water to cool the system. This will make each kilowatt-hour of electricity it produces more expensive (dry cooling is less efficient than the cooling systems we typically use). But, it has the advantage of drastically lowering the water requirements of the plant.
With this go-ahead, Tenaska Inc. has announced its plans to break ground on this facility in 2011 to supply its first megawatt-hour in 2015.