Mass. Gen. Laws ch. 25, § 19
(a) The department shall require a mandatory charge of 2.5 mills per kilowatt-hour for all consumers, except those served by a municipal lighting plant, to fund energy efficiency programs including, but not limited to, demand side management programs. The programs shall be administered by the electric distribution companies and by municipal aggregators with energy plans certified by the department under subsection (b) of section 134 of chapter 164. In addition to the aforementioned mandatory charge, such programs shall also be funded, without further appropriation, by: