This is more proof that rooftop systems are a strong net benefit to non-solar customers, as also shown in costly contradictions by Utilities Commission’s Duke-friendly Public Staff
A consultant for organizations agreeing with Duke Energy’s changes to the state’s net metering rules filed evidence in March that ironically kills Duke’s only argument – that rooftop solar systems unfairly shift power grid costs onto non-solar customers. In documents filed in the NC Utilities Commission case by the NC Sustainable Energy Association (NCSEA) and others, the prominent net metering expert, Tom Beach, cited evidence that Duke undervalued solar’s benefits for all power users by a whopping 4 to 5 cents per kilowatt-hour by ignoring future cost increases of fossil fuels and carbon emissions.
That finding alone pushes system-wide benefits of rooftop solar well past the “cost shift” Duke claims would harm non-solar customers. To top that, Beach also wrote that, when societal benefits are considered (as Gov. Roy Cooper has called for) the value of rooftop solar is doubled. As Attorney General Josh Stein emphasizes in the ongoing case, a 2017 state law firmly requires the NCUC to conduct a comprehensive cost-benefit analysis before making any changes to net metering, but Duke continues to defy that requirement.
These are core points in an upcoming filing in the case by NC WARN, Sunrise Durham and the NC Climate Solutions Coalition. They are part of the analysis by our long-time consultant, engineer Bill Powers, who is also a nationally prominent expert. In March, 17 rooftop solar companies urged Cooper to protect their industry, and three are parties in the NCUC case. Some 56 pro-solar nonprofits also oppose Duke’s attempt to limit solar.
Powers also reports an extreme contradiction in filings by the Public Staff (PS) that further reverses Duke’s unsupported “cost shift” allegation. The PS expresses concern – in another proceeding – about the high and uncertain costs of transmission upgrades to interconnect new utility-scale solar, but seems okay with Duke omitting those savings when tallying net metering’s benefits.
Powers calculates that rooftop solar would avoid much of the transmission costs associated with certain utility-scale solar projects being evaluated by Duke Energy – further reversing Duke’s alleged cost shift. Similar savings also apply to dozens of gas-fired units Duke plans to build in the Carolinas.
Other key findings in our upcoming filing:
- NCSEA consultant Beach shows a 24% loss of value for a solar investment under Duke’s scheme unless households make major changes in usage patterns, such as buying an electric vehicle. Solar companies say the loss is up to 35%. Duke’s own documents show a 30% loss, and the Public Staff shows it could be 58%.
- Beach acknowledges that Duke’s proposed “smart thermostat” incentive will be available to fewer than half of Duke Energy’s residential customers. NCSEA recognizes that even the incentive payment doesn’t provide much economic motivation for potential rooftop solar customers.
- NCSEA’s Beach: “Most important, the package of [net energy metering] reforms is complex, requiring customers to understand a new, complicated TOU/CPP rate design … is far more complex than traditional [net metering] …” [emphasis added]
- Duke’s own 2021 pilot study found the best window for shifting peak load is 2pm-8pm in warm months. But the corporation ignored those findings by setting the on-peak window in its NCUC proposal at 6 to 9pm – too late to benefit solar customers.
- Duke and NCSEA tout cost features in the proposal that are designed to minimize rooftop system sizes. Powers calls it “poor tariff design” that discourages customers from maximizing their solar output and helping achieve state climate pollution targets.
- NCSEA acknowledges that battery storage does not “pencil out” under Duke’s proposal, although storage has become an integral aspect of the rooftop solar market.
- After pressing Duke Energy to explain why it “declined to perform a Value of Solar Study,” the Public Staff dropped that request while relying on a consulting firm that has consistently low-balled net metering’s value while working for US utilities.
All signs point to net metering’s value being well above the retail cost of residential grid power, and vital to climate protection and our economy. Duke Energy officials have no case for attacking rooftop solar, and their urgency to get changes approved is also contrived. A 2017 energy law said merely that current net metering customers must be allowed to keep their current plan until 2027. Duke has spun that into a bogus claim that there is a 2027 deadline for approving new net metering rules.
Florida Gov. Ron DeSantis, a right-wing Republican, recently protected rooftop solar by vetoing a pro-utility net metering bill after a prolonged fight over solar power. Surely Gov. Cooper and the utilities commission can protect our rooftop solar industry too.