Value of distributed solar energy

What is the value of distributed solar photovoltaic electric generation?  An investigation by the Maine Public Utilities Commission into this question is ongoing, and will culminate in a report to the state legislature this winter.  At stake are policies and incentives to foster the growth of solar energy in Maine.

Distributed solar generation -- such as solar panels on rooftops and ground-mounted solar arrays -- is a small but rapidly growing sector of the U.S. energy mix.  Solar panels can produce renewable electricity, with no direct fuel use, emissions, or reliance on foreign energy sources.  Customer-sited and other distributed generation resources can also enhance the reliability of the local electric grid, and reduce the need for more expensive transmission and distribution upgrades.  The growing shift to solar energy is also seen as a driver of jobs and economic development.

Rooftop solar photovoltaic panels on a business in Patten, Maine.

In recognition of these benefits, states and the federal government have enacted a variety of policies and incentives for solar power development and use.  These policies include renewable portfolio standards which mandate that utilities source certain amounts of their power from renewable resources, as well as net metering policies which allow a customer to offset its power bill with energy produced from on-site solar panels.

But what is the true value of distributed solar energy resources?  In an effort to find out, in 2014 the Maine Legislature enacted An Act To Support Solar Energy Development in Maine.  This law is also known as the Maine Solar Energy Act, P.L 2013 Chapter 562 (codified at 34-B M.R.S. §§ 3471-3473).  The law expresses the legislative finding that Maine's solar energy resources "constitute a valuable indigenous and renewable energy resource."  Moreover, the law is predicated on the findings that solar energy development is unique in its benefits to and impacts on the climate and the natural environment, and that it can help Maine because it can displace fossil fuel combustion and associated air pollution and greenhouse gas emissions.   The Act set a state policy "to encourage the attraction of appropriately sited development related to solar energy generation, including any additional transmission, distribution and other energy infrastructure needed to transport additional solar energy to market, consistent with all state environmental standards; the permitting and financing of solar energy projects; appropriate utility rate structures; and the siting, permitting, financing and construction of solar energy research and manufacturing facilities for the benefit of all ratepayers."

With these findings noted, the Act directed the Maine Public Utilities Commission to construct a report by February 15, 2015 on the value of distributed solar energy generation in Maine.  In so doing, the Act requires the Commission to develop a method for valuing distributed solar energy generation.   By statute, this method must, at a minimum, account for:

• the value of the energy;
• market price effects for energy production;
• the value of its delivery, generation capacity, transmission capacity and transmission and distribution line losses; and
• the societal value of the reduced environmental impacts of the energy.

The also Act requires the Commission's report to include a summary of options for increasing investment in or deployment of distributed solar energy generation, which may include recommendations for what Maine should do.

The Commission's investigation is ongoing.  On October 23, 2014, the Commission released a draft of its consultants' initial report, "Maine Distributed Solar Valuation Methodology."  That document is designed as a draft of the methodology to be used in the valuation phase, offered for public review and comment.

The Commission will accept written comments on the draft report until November 12, 2014.  In addition, the Commission and its consultant, Clean Power Research, will hold a work session on the Draft Methodology on October 30, 2014.

Following the first phase to establish the valuation methodology, the Commission and its consultants will conduct a second phase in which the methodology will be applied to Maine to calculate the value of distributed solar generation.  The Commission's work will be summarized in its report to the legislative energy committee, a draft of which the Commission plans to release in January 2015.