SECTION 1. The Department of Energy Resources is required to undertake a study of , either independent of or part of any review of thermal energy sources, the benefits of expanding the use of renewable gas, also known as biomethane,  as a  renewable energy source within Massachusetts.  The study will include the use of renewable gas from multiple souces, including municipal solid waste, wood residues, livestock manure, energy crops, landfill gas, and wastewater treatment plants. The study shall look at mechanisms, both incentives and mandated minimum requiremnts, to expand the use of renewable gas.  The study of the benefits shall focus on the use of renewable gas in meeting greenhouse gas reduction targets; stimulating the local economy and providing jobs; enhancing the diversity of fuel supply; and leveraging the existing gas network.  The report shall be filed with the Joint Committee on Telecommunications, Utilities and Energy by March 1, 2012.