The Southcentral Power Project in Anchorage, Alaska, is an example of how highly efficient combined-cycle, natural gas-fired power plants are becoming increasingly important in the US power generation industry. In July 2010, Chugach Electric Association Inc., Alaska’s largest electric utility, and Municipal Light & Power, awarded SNC-Lavalin the engineering, procurement and construction contract for the project.
Natural gas is the primary fuel for electricity production in southcentral Alaska, and the biggest concern among electricity providers is the region’s limited supply, particularly during the cold and dark winter months. The new power plant’s advanced technology uses natural gas more efficiently to ensure it is not wasted. As a result, Power Engineering Magazine named Southcentral Power Plant the most efficient power plant in Alaska.
Southcentral is equipped with three GE LM6000PF gas turbines rated at 48 MW each. The turbines were chosen for both their efficiency and their fast-start capability, which allows them to reach full capacity in just 10 minutes. The plant is also equipped with Once Through Steam Generators (OTSGs) that can be duct fired to increase plant capacity to 200 MW. The technology used in the plant has reduced carbon dioxide emissions by 25 percent and carbon monoxide and nitrous oxide by 95 percent.
Exceeding projected savings
SNC-Lavalin completed the contract in March 2013, five months ahead of the utility’s plan for power delivery and well under its budget. The plant also exceeded projected savings for the first year. It was estimated that the new plant would save more than $15 million in avoided fuel purchases. As of November 2013, the savings totaled $21.7 million.