The Green Communities Act of Massachusetts is a sweeping piece of legislation slated to fully take effect in the coming months. Passed in 2007, this energy and environmentally focused act promises to make Massachusetts a leader in addressing climate change and energy independence. All of the regulations are currently being hashed out by the public and other stake holders with the goal being to have all the nuances of the act agreed upon so the regulations can be put into practice in the new year. While we could write a book on all the great, good and (few) not so good aspects of the act, for this series of posts we are going to focus on the changes to Net Metering as it pertains to distributed generation. Net Metering itself is a dense subject, so this first post will deal only with the definition. (in depth: Net Metering at a national level)
Net Metering is a concept that has been in practice to varying degrees for many years in many states. The concept is simple in theory. A customers electricity meter has the ability to spin backwards when generation on site exceeds use and electricity is flowing backwards onto the grid. Let’s use a school with a wind turbine as an example. The school has a large ‘load’ (electric use) during very specific times of day, month, and year. During the weekends, summer months, and night time there is very little usage. But when school is in session or there is a football game and all the stadium lights are on the electric meter is spinning very quickly as a large amount of electricity is being used. Then, during a quiet but gusty evening during Christmas break, the wind turbine is generating at full capacity but there is no use at the high school. So this electricity goes back onto the grid and the electricity meter spins backwards.
Before Net Metering this electricity would be purchased by the utility who owns the lines in the area at the whole-sale rate or some other agreed upon (but low) rate. And to receive even this low price there were many hurdles to jump through, many of which were too high for small-scale generators like residential wind and solar owners. With Net Metering in Massachusetts each kilowatt hour of electricity generated but not used on site creates a net excess generation (NEG) credit. These credits can be used to cancel out electricity purchased when the wind turbine is inactive. So at the end of the year (or month, as is the case in MA) the amount you use is counterbalanced by the amount you generate. So the intermittency of solar and wind generation is no longer a disadvantage. If your wind turbine only spun at night while you had zero electric use but over a year it produced exactly the amount of electricity you used, your bill would be zero.
Considering the old method of recieving the wholesale rate for power generated, which is often under 30% of what someone pays at the outlet, Net Metering promises to make many renewable energy projects economically feasible in Massachusetts as each NEG credit has the worth of what you pay at the outlet. In later posts we’ll discuss why the Net Metering regulations must have system size caps as well as some of the innovative structures promoted in the Green Communities Act such as Neighborhood Net Metering.
- Photo Credit: Sunrise at Hull 1, Photo by Nantaskart!
