The expansion, which brings the total number of turbines at the Dayton, Columbia County facility to 87, is another step for the utility and the region toward a sustainable energy future, the company said.

Hopkins Ridge began operation in November 2005 with 83 wind turbines capable of producing 150MW of electricity. With the four new 1.8MW turbines fully operational, total capacity at the facility rises to 157MW, or the energy equivalent of that required to serve more than 40,000 homes.

Kimberly Harris, executive vice president and chief resource officer for Puget Sound Energy, said: Wind power and southeastern Washington are a great team. Hopkins Ridge is both a valuable contributor to meeting renewable energy needs, and to the local economy and tax base in Dayton and Columbia County.