Municipal Light Departments in Massachusetts: What are they and why should you care?

Quick Link: Municipal Light Plants in Massachusetts: Spotlight on Clean Energy Initiatives

For most communities in Massachusetts, electricity is provided by an Investor Owned Utility (IOU) such as National Grid, or Eversource. For some, though, electric power is a governmental service, like sewer or water, provided by a Municipal Light Department or “muni.”

There are 41 munis in Massachusetts, serving some or all of 50 different communities, but to many they are a mystery. For instance, why do some communities have a muni, while others do not? What’s the difference between a muni and an IOU? Are all munis the same? Can your town create a muni if they want to? And how did they come to exist in the first place? These are just some of the questions we answer in MAPC’s newest white paper, Municipal Light Plants in Massachusetts: Spotlight on Clean Energy Initiatives.

Munis are nonprofit entities, and compared to IOUs, they serve a small number of customers in a limited geographic region. Munis are highly independent, and are not under the same mandated obligation of IOUs to purchase a percentage of their power from renewable energy sources. These are some of the reasons that munis are able to offer lower rates than IOUs, while providing equal or better service. It also means that most munis do not participate in statewide efficiency and renewable energy programs such as the utility sponsored Mass Save program, or DOER’s Green Communities initiative.

Many munis do develop their own efficiency and renewable programs, and in many cases their independence and autonomy are used as an advantage, allowing for easier implementation and greater innovation. The Wellesley Municipal Light Department in the Town of Wellesley, for example, converted 540 streetlights to more efficient LED technology without having to go through the step of purchasing those lights back from a utility (a sometimes arduous process for IOU communities). Holyoke Gas and Electric, is partnering with Sparkplug Power, an energy storage company in Somerville, MA, and the University of Massachusetts Amherst, to develop a residential energy storage demonstration project. They are installing lithium batteries in customers’ homes, charging them during hours of low demand, and using that stored power during times of peak demand. The goal is to manage the higher costs of peak demand power and alleviate overall stress on the grid.

The above are just a few examples that we discuss more in depth in the white paper. The point is not that munis are better than IOUs, or vice versa. One major takeaway, though, is that munis, with their local control and independence, are creating interesting and innovative programs and projects. There is still a great opportunity for increased collaboration and communication between munis, as well as between munis and the utilities, in creating support for community investment in efficiency and renewable energy. Just as state and local governments have been incubators of innovation in all areas such as education, healthcare, and crime, Massachusetts’ munis can be the testing ground for new innovations in energy efficiency and clean energy in our state and beyond.


Neal Duffy, Clean Energy Intern


Wellesley light plant