Terms & Definitions

The list below includes terms frequently used when discussing aggregation, electricity, and renewable energy.

Basic Service – When your electric utility, Eversource, is also your electricity supplier, you have a service called Basic Service. You have Basic Service if you do not sign a contract with an electricity supplier on your own, or if you opt out of participating in a municipal electricity aggregation program, such as the Natick Electricity Aggregation Program.

When you have Eversource’s Basic Service, Eversource uses their Basic Service price to calculate the Supply portion of your electric bill. The Basic Service price changes every 6 months for residential and small business customers and every 3 months for large business customers. (For January 2024 – July 2024, there will be a one-time, 7-month Basic Service period for residential and small business customers.)
However, if you sign a contract with an electricity supplier on your own or you participate in a municipal electricity aggregation program, such as the Natick Electricity Aggregation Program, Eversource does not use their Basic Service price to calculate the Supply portion of your electric bill. Instead, Eversource uses the price in your contract or the aggregation price to calculate the Supply portion of your electric bill.

“Clean” electricity – Clean electricity is electricity that is generated by a renewable energy resource that does not generate pollution or emissions, such as the sun or the wind, and not by burning fossil fuels like gas, oil, or coal.

Electricity delivery (sometimes referred to simply as delivery, and also as distribution) – This term refers to the service of delivering electricity to you through poles and wires, and also to the maintenance of that electricity delivery infrastructure. Electricity delivery charges appear on the Delivery portion of your Eversource electric bill. Electricity delivery charges do not include the cost of the electricity itself. Those charges appear on the Supply portion of your Eversource electric bill.

Electricity supplier – An electricity supplier is a company that buys electricity on your behalf. The price that your electricity supplier charges is the price that is used to calculate the Supply portion of your Eversource electric bill. In Massachusetts, you can choose who your electricity supplier is.

Your electric utility, Eversource, can serve as your supplier. In that case, you have Eversource’s Basic Service, and Eversource both buys electricity for you and delivers electricity to you.
You can select an electricity supplier on your own. In that case, Eversource only delivers electricity to you.
Your municipal government can establish an electricity aggregation, and with that program, the Town can select an electricity supplier for you, as with the Natick Electricity Aggregation Program. In that case, Eversource only delivers electricity to you.

Electricity supply (sometimes referred to simply as supply) – This term refers to the electricity that is delivered. Electricity supply charges appear on the Supply portion of your Eversource electric bill. Electricity supply charges are calculated by multiplying the amount of electricity you use (in kilowatt hours) by a price. Electricity supply charges do not include charges for the delivery of the electricity or for the maintenance of electricity-related infrastructure. Those charges appear on the Delivery portion of your Eversource electric bill.

“Green” electricity – Green electricity is electricity that is generated by a renewable energy resource, such as the sun or the wind and not by burning fossil fuels like gas, oil, or coal.

Renewable energy – Renewable energy is energy generated by sources that we won’t run out of, such as the sun and the wind. Renewable energy sources also do not create the gases that cause climate change. (Traditionally, electricity has been generated by burning fossil fuels like coal, oil, and gas. Fossil fuels are available in a limited quantity, and burning them creates the gases that cause climate change.) Under Massachusetts state law, a variety of resources qualify as renewable. The main sources of renewable electricity are solar, wind, and small hydroelectric projects. Renewable electricity is electricity that is generated by renewable energy projects and is sometimes referred to as “green” electricity.

Renewable energy certificates (RECs) – RECs are a method of keeping track of renewable electricity. One REC is minted for every 1 megawatt-hour of electricity generated. RECs are tracked in a central database known as the NEPOOL GIS (generation information system). Electricity customers who wish to be able to say they are purchasing green or renewable electricity from the grid can pay for RECs in addition to paying for the electricity they use. Purchasing RECs gives an electricity customer the right to say they have used the electricity generated by renewable energy systems instead of using electricity generated by burning fossil fuels. Once a REC is purchased, it is then retired so that no one else can purchase it and claim to have used the same renewable energy.

Renewable Portfolio Standard (RPS) – The RPS is a minimum amount of renewable energy that is required by law in the electricity sold in a state by the utilities and other electricity suppliers. Massachusetts has an RPS, as do many other states. An RPS specifies both the amount and type of renewable energy that must be included in the electricity that is sold. Because of the Massachusetts RPS, all electricity sold in the state includes a minimum amount of renewable energy. Massachusetts also has an APS, an Alternative Portfolio Standard, which requires that all electricity include a minimum amount generated by alternative energy sources, which are typically highly efficient but not renewable. Read more on the Massachusetts DOER website.

Opt up – To opt up is to choose an option in the Natick Electricity Aggregation Program that includes more than the standard level of additional renewable electricity.

Opt out – To opt out of the Natick Electricity Aggregation Program is to leave the program. You have the right to participate in the program for as long as you like, and to opt out at any time with no penalty or fee.

Utility – In Massachusetts, an electric utility is an electricity delivery, or distribution, company. Electric utilities do not generate electricity. They purchase electricity and then deliver it to you, the customer. You have no choice in your electric utility; they have geographic monopolies. In Natick, your electric utility is Eversource. If you do not participate in a municipal electricity aggregation program like the Natick Electricity Aggregation Program, and you do not sign your own contract with an electricity supplier, your utility will also buy electricity for you.