Dr Tierney is an expert on energy policy and economics, specializing in the electric and gas industries, with 25 years of experience in the energy sector. She has experience in public utility and environmental regulation, and has worked with private consulting firms.

She is currently a managing principal with the Analysis Group, a nationwide firm founded in 1981 that provides economic, financial, and business strategy consulting services to law firms, corporations, and government agencies.

Richard Feldt, chairman, president and CEO of Evergreen Solar, said: We are extremely pleased to welcome Dr Tierney to our board. She brings a wealth of energy industry expertise from both her public and private sector experiences that will be invaluable to us as we expand production and further our relationships with utilities and other companies downstream in the value chain.