On the Blogs: Growing Body of Research Finds Net Benefits in Rooftop Solar
FacebookTwitterLinkedInEmailPrint分享Mark Muro and Devashree Saha for the Brookings Institute:Does net metering really represent a net cost shift from solar-owning households to others? Or does it in fact contribute net benefits to the grid, utilities, and other ratepayer groups when all costs and benefits are factored in? What does the accumulating national literature on costs and benefits of net metering say? Increasingly it concludes— whether conducted by PUCs, national labs, or academics — that the economic benefits of net metering actually outweigh the costs and impose no significant cost increase for non-solar customers. Far from a net cost, net metering is in most cases a net benefit—for the utility and for non-solar rate-payers.By the end of 2015, regulators in at least 10 states had conducted studies to develop methodologies to value distributed generation and net metering, while other states conducted less formal inquiries, ranging from direct rate design or net-metering policy changes to general education of decision makers and the public. And there is a degree of consensus.In 2013 Vermont’s Public Service Department conducted a study that concluded that “net-metered systems do not impose a significant net cost to ratepayers who are not net-metering participants.” The legislatively mandated analysis deemed the policy a successful component of the state’s overall energy strategy that is cost effectively advancing Vermont’s renewable energy goals.In 2014 a study commissioned by the Nevada Public Utility Commission itself concluded that net metering provided $36 million in benefits to all NV Energy customers, confirming that solar energy can provide cost savings for both solar and non-solar customers alike. What’s more, solar installations will make fewer costly grid upgrades necessary, leading to additional savings. The study estimated a net benefit of $166 million over the lifetime of solar systems installed through 2016. Furthermore, due to changes to utility incentives and net-metering policies in Nevada starting in 2014, solar customers would not be significantly shifting costs to other ratepayers.A 2014 study commissioned by the Mississippi Public Services Commission concluded that the benefits of implementing net metering for solar PV in Mississippi outweigh the costs in all but one scenario. The study found that distributed solar can help avoid significant infrastructure investments, take pressure off the state’s oil and gas generation at peak demand times, and lower rates. (However, the study also warned that increased penetrations of distributed solar could lead to lower revenues for utilities and suggested that the state investigate Value of Solar Tariffs, or VOST, and other alternative valuations to calculate the true cost of solar.)In 2014 Minnesota’s Public Utility Commission approved a first-ever statewide “value of solar” methodology which affirmed that distributed solar generation is worth more than its retail price and concluded that net metering undervalues rooftop solar. The “value of solar” methodology is designed to capture the societal value of PV-generated electricity. The PUC found that the value of solar was at 14.5 cents per kilowatt hour (kWh)—which was 3 to 3.5 cents more per kilowatt than Xcel’s retail rates—when other metrics such as the social cost of carbon, the avoided construction of new power stations, and the displacement of more expensive power sources were factored in.Another study commissioned by the Maine Public Utility Commission in 2015 put a value of $0.33 per kWh on energy generated by distributed solar, compared to the average retail price of $0.13 per kWh — the rate at which electricity is sold to residential customers as well as the rate at which distributed solar is compensated. The study concludes that solar power provides a substantial public benefit because it reduces electricity prices due to the displacement of more expensive power sources, reduces air and climate pollution, reduces costs for the electric grid system, reduces the need to build more power plants to meet peak demand, stabilizes prices, and promotes energy security. These avoided costs represent a net benefit for non-solar ratepayers.These generally positive PUC conclusions about the benefits of net metering have been supported by research done by a national lab and several think tanks. Important lab research has examined how substantially higher adoption of distributed resources might look.In a forward-looking analysis of the financial impacts of net-metered energy on utilities and ratepayers, Lawrence Berkeley National Lab found that while high use of net-metered solar generation may decrease utility shareholders’ earnings, it will have a “relatively modest” impact on ratepayers. The report examined solar penetration levels that are “substantially higher than [those that] exist today” — 10 percent compared to today’s 0.2 percent — and concluded that “even at penetration levels significantly higher than today, the impacts of customer-sited PV on average retail rates may be relatively modest.” The report further said that utilities and regulators “may have sufficient time to address concerns about the rate impacts of PV in a measured and deliberate manner”Similarly, a growing number of academic and think tank studies have found that solar energy is being undervalued and that it delivers benefits far beyond what solar customers are receiving in net-metering credits:For instance, a review of 11 net metering studies by Environment America Research and Policy Center has found that distributed solar offers net benefits to the entire electric grid through reduced capital investment costs, avoided energy costs, and reduced environmental compliance costs. Eight of the 11 studies found the value of solar energy to be higher than the average local residential retail electricity rate: The median value of solar power across all 11 studies was nearly 17 cents per unit, compared to the nation’s average retail electricity rate of about 12 cents per unit.A 2015 cost-benefit study of net metering in Missouri by the Missouri Energy Initiative found that even accounting for increased utility administrative costs and the shifting of some fixed expenses, net metering is a net benefit for all customers regardless of whether they have rooftop solar. The study used values for two kinds of costs and two benefits and concluded that net metering’s “net effect” is positive. The typical solar owner pays only 20 percent less in fixed grid costs and costs the utility an estimated $187 per interconnection. Meanwhile, solar owners benefit the system through reduced emissions and energy costs.Likewise, a study by Acadia Center found the value of solar to exceed 22 cents per kWh of value for Massachusetts ratepayers through reduced energy and infrastructure costs, lower fuel prices, and lowering the cost of compliance with the Commonwealth’s greenhouse gas requirements. This value was estimated to exceed the retail rate provided through net metering.In yet another study, researchers at the University at Albany, George Washington University, and Clean Power Research have found that solar installations in New York deliver between 15 and 40 cents per kWh to ratepayers. The study noted that these numbers provide economic justification for the existence of incentives that transfer value from those who benefit from solar electric generation to those who invest in solar electric generation.In short, while the conclusions vary, a significant body of cost-benefit research conducted by PUCs, consultants, and research organizations provides substantial evidence that net metering is more often than not a net benefit to the grid and all ratepayers.Full item: Rooftop solar: Net metering is a net benefit On the Blogs: Growing Body of Research Finds Net Benefits in Rooftop Solar