ORIGINAL REPORTING: How Much Is Rooftop Solar Worth

Amid rising rooftop solar battles, emerging net metering alternatives could shake up the sector; A “holistic product bundle” of DER could offer not "just a transition" but "a just transition,” tariff analysts say.

Herman K. Trabish, March 18, 2021 (Utility Dive)

Editor’s note: Stakeholders say this debate will be decided in California this year.

The costs to non-solar owning customers of net energy metering (NEM) policies that support rising levels of rooftop solar in more than 29 states have created division between utilities and DER advocates, but elements of a new policy that can balance the cost shift with system benefits for all customers are emerging, power system analysts say.

Distributed solar owners in many states pay only for the net kilowatt-hours on their meters after compensation for exported solar-generated kilowatt-hours is deducted at the retail electricity rate. This NEM policy does not significantly shift system costs to other customers at low solar penetrations, but the accelerating growth of distributed energy resources (DER) is creating growing concerns about a cost shift from customers who own solar to those who don't.

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NEM "is a useful tool, but it's just a tool," Edison Electric Institute (EEI) General Counsel and Senior Vice President for Clean Energy Emily Fisher told a Feb. 9 National Association of Regulatory Utility Commissioners (NARUC) Winter Summit audience during one of three panels on NEM. "There are ways to reform it to allow even greater benefits from DER and still avoid imposing a cost shift."

DER advocates at the conference agreed NEM must evolve. DER can be "leveraged for many grid services critical to achieving zero emissions goals," Strategen Managing Director for US Consulting Matt McDonnell said. But "rate designs need to evolve to more fully integrate DER for those services or we will miss taking advantage of customer investments, overbuild the system, and fewer customers will face larger fixed costs."

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Discussions about an NEM successor tariff to sustain DER growth has, until recently, led only to controversy. But NARUC summit presentations suggested there may be some emerging consensus on policy elements like adding incentives for storage. And a new South Carolina proposal involving Duke Energy offers a "holistic product bundle" that could lead to "new possibilities," according to summit panelists.

An NEM successor tariff becomes important when DER penetrations of over 5% of system peak load threaten to impose significant costs for system infrastructure on non-solar owning customers, "and more states are moving toward that level," said North Carolina Clean Energy Technology Center (NCCETC) Senior Policy Program Director Autumn Proudlove. Legislative and regulatory policy actions on distributed solar steadily increased from 2015 to 2020, Proudlove told the NARUC summit. In 2020, DER compensation was the focus of 92 actions in D.C. and 34 states, up from just 41 actions in 26 states in 2015… click here for more

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