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Maine Public Utilities Commission Issues Decision on Customer Net Energy Billing

January 31, 2017

Hallowell, Maine – The Maine Public Utilities Commission (Commission) approved revisions today to Chapter 313, the Customer Net Energy Billing (NEB) Rule. "The Commission received many useful comments over the last several months regarding this Rule and all the comments were reviewed and analyzed carefully" noted Commission Chairman Mark Vannoy. "The resulting rule a) grandfathers existing customers for fifteen years, b) for new entrants it locks in the phase down level, at the year in which they enter, for fifteen years, and c) maintains incentive margins consistent with the declining costs of solar technology." The Commission focused its decision narrowly on residential rooftop solar. Below is a more detailed explanation of the major components of today's decision.

  1. Grandfathering of Existing NEB Customers. All existing customers and new customer installations that occur prior to January 1, 2018 will be grandfathered for fifteen years. This means those customers will receive the current incentives and terms as they exist today.

  2. Grandfathering of New Entrants to NEB. As new customers sign up over the next 10 years, netting of the transmission and distribution (T&D) portion of the bill will be gradually decreased to reflect reductions in the costs of small renewable generation technology. For example, in year 1 NEB customers will receive the full value of the supply portion, and 90% of the T&D portion for each year of the fifteen years.

  3. Maintaining Incentive Levels. The incentives to NEB customers under the new Rule should not change the length of time it takes for a customer to recoup their investment. The estimated payback for new installations will be similar to what it has been historically. As noted above, for a customer installation signed in year one, the full incentive for supply and 90% of the incentive for T&D is received for fifteen years. As the cost of technology declines, the incentive for T&D also declines for new entrants. For a new customer installation in year two, for example, the cost of the solar panels will have declined but the incentive will also decline to 80% for T&D and the full incentive for supply.

  4. Rule Addresses Residential Rooftop Solar Only. Many projects are being built across the state today based on existing market mechanisms. The Commission decided not to address larger scaled projects and community projects as part of the NEB rules to ensure we stayed within our regulatory function, and in light of legislative initiatives in these areas.

  5. Includes Renewable Energy Credit (REC) Based Revenue Stream. The new Rule allows an NEB customer to choose to monetize the value of their solar generation and receive a credit for that value. NEB installations will be automatically classified as a Maine Class I Renewable Resource.

Background: Chapter 313 of the Commission’s rules governs net energy billing (NEB) in Maine. NEB is a metering and billing mechanism that is generally used to promote the development and operation of smaller renewable generation facilities. In January 2016, Central Maine Power Company (CMP) filed a letter stating that, at the end of calendar year 2015, the cumulative capacity of the generating facilities for which CMP has net energy billing agreements under Chapter 313 is approximately 1.04% of CMP’s annual peak demand. Consequently, CMP requested that the Commission undertake the review of net energy billing required by Section 3(J) of Chapter 313. In response to the CMP January 14, 2016 letter, the Commission, on June 14, 2016, issued a Notice of Inquiry to obtain comment and information from interested persons regarding Maine’s NEB rules and whether the rules should be modified in light of changing economics and markets. On September 13, 2016 the Commission issued a Proposed Rule and requested comments on that rule. On October 17, 2016 the Commission held a public hearing on the Proposed Rule and received several hundred written comments as well.


The Maine Public Utilities Commission regulates electric, telephone, water and gas utilities to ensure that Maine citizens have access to safe and reliable utility service at rates that are just and reasonable for all ratepayers. Commission programs include Maine Enhanced 911 Service, and Dig Safe.

Contact: Harry Lanphear, 287-3831