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Capacity vs. Energy

How MMWEC MLPs Meet their Capacity & Energy Requirements

The municipal utility members of MMWEC must meet capacity and energy obligations, per the rules of the regional transmission organization, ISO New England.  Click on the flyer below to read more. 


What's the Difference Between Capacity & Energy?

Capacity and energy are both components of the electric grid, but they function differently. See the flyer below to learn why MLPs need to own capacity on behalf of their customers.


Project 2015A Helps Participants Fulfill their Capacity Requirements

2015A Provides Capacity and Reliability

  • All MLPs, as load-serving entities, are required to provide capacity to ISO New England
  • 14 MLPs are participating in 2015A as Project Participants for the capacity
  • Capacity must be available to cover the MLP’s peak load, plus a reserve margin
  • Prices in the ISO New England capacity market are volatile; 2015A locks in a price, protecting MLPs against this price volatility
  • Having this capacity reliability resource helps the MLP stabilize rates and plan for the future

2015A is Not an Energy Resource

  • Project 2015A will account for only .535% of Project Participant energy needs
  • Energy is the amount of electricity used by the customers of an MLP; measured in kilowatt hours, energy usage varies through the year and the day
  • Approximately 30% of MMWEC Member capacity requirements is covered by entitlements from fossil resources; these capacity resources contribute less than 1.8% of total energy consumption for MMWEC Members

2015A is Essential for the Increased Use of Renewable Energy Resources

  • Having the required capacity through 2015A allows MLPs to purchase or own more renewable energy, such as MMWEC solar Project 2020A, Berkshire Wind Phase I and Berkshire Wind Phase II
  • The intermittent nature of renewable sources means they provide very little capacity
  • Because of their intermittent characteristics, ISO-NE allows for only .311 of capacity for every 1 MW of Berkshire Wind, and .117 of capacity for every 1 MW of solar, on an annual average

MMWEC MLPs' Clean Energy Timeline

MMWEC and its members have been incorporating carbon-free power into their portfolios for decades, dating back to the 1980s. Click on timeline below for major accomplishments to date.