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Maine Net-Metering Rules

Date Last Updated5/15/2013
Policy TypeNet-Metering Policy
Policy Administrator/Contact OfficeMaine Public Utilities Commission
Policy Initiation Date1/1/1987
Policy SummaryNet-metering has been available in Maine since 1987 for owners of qualified CHP and small power-production facilities <100 kW. However, in April 2009, LD 336 authorized the final adoption of the rule, amending it to include high efficiency micro-CHP systems as eligible. Micro-CHP systems are defined as a system that produces heat and electricity from one fuel input, without restriction to specific fuel or generating technology with an electric generating capacity rating of at least one kilowatt and not more than 30 kilowatts and a fuel system efficiency of not less than 80% in the production of heat and electricity or has an electric generating capacity of at least 31 kilowatts and not more than 660 kilowatts and a fuel system efficiency of not less than 65% in the production of heat and electricity.

All of Maine's electric utilities -- investor-owned utilities, municipal utilities and electric cooperatives -- must offer net-metering.

Net excess generation (NEG) is credited to the following month for up to 12 months; after the end of an annualized period, all NEG is granted to the utility with no compensation for the customer. At its own expense, a utility may install additional meters to record purchases and sales separately. There is no limit on the aggregate amount of energy generated by net-metered customers. However, a utility must notify the PUC if the cumulative capacity of net-metered facilities reaches 1.0% of the utility's peak demand.
CHP Eligibility RequirementsBoth fossil-fueled and renewably-fueled CHP systems are eligible for net-metering.
Eligible Project Size (MW)Micro-CHP systems <660kW are eligible to net-meter. <100 MW for fuel cell CHP or anaerobic digester gas fueled CHP systems are potentially eligible to net-meter.
Minimum Efficiency Required/
Other Performance Requirements
Micro-CHP <30 kW must achieve combined electrical and thermal efficiency of 80% or greater, and micro-CHP systems between 30 kW and 660 kW must achieve combined efficiency of 65% or greater.
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