Originally passed in 1982, the Dept. of Telecommunications and Energy made two changes to the net metering program in 1997. One, allowable capacity was increased from 30kW to 60kW. Two, utilities are no longer required to purchase net excess generation at their avoided cost. Rather, any NEG at the end of the month will be credited at the average monthly market rate to the next month's bill. So in effect customers are paid the retail rate for their NEG, except that it is assumed there will be no net generation on a yearly basis. At no point, therefore, does the utility actually purchase power from the facility.

View Massachusetts Net Metering Law
220 Code of Massachusetts Regulation, Section 11.04(7)(C).

Other Resources:

• New Rules Project's section on Net Metering Rules
• Model Net Metering Law for Renewable Energy Technologies - by the Interstate Renewable Energy Council, August 2003
  This model limits net metering to systems 25 kW or less for residential applications and 100 kW or less at commercial sites. The rule would allow first-come first-served net metering until a utility reaches 2 percent of its peak load.
• Summary of Net Metering Programs in the United States - by DSIRE, ongoing updates
• Consumer Guide to Renewable Energy for Your Home or Business - by DOE Office of Power Technologies
• Green Power Networks' State Net Metering Program Descriptions