Rooftop solar saved not just panel owners, but all California customers $2.3 billion on utility bills in 2024, according to a blockbuster new report. The study found that the rooftop panels saved non-solar customers $1.5 billion, rebutting the utility industry’s bogus “cost-shift” myth.
Researchers found that rooftop solar made electricity cheaper for all California customers by lowering peak demand for electricity and reducing the amount utilities need to spend on buying energy and expanding the grid.
Because utilities build the cost of purchased energy and capital investments into the rates they charge customers over a period of years, the money saved in not building out the grid and buying energy translates to lower rates down the road.
The researchers, from environmental analysis firm M.Cubed Consulting, found that rooftop solar had displaced 15,000 megawatts of peak load since the start of California’s Million Solar Roofs initiative in 2006 – adding up to $2.17 billion in savings in 2024.
M.Cubed’s findings form a strong rebuttal to a previous report released by a branch of California’s public utility commission (PUC), which falsely claimed that rooftop solar was increasing costs to customers of the state’s three largest utilities by over $8 billion.
The PUC report’s accounting was based on the logic of the utility industry’s so-called “cost shift” myth – which uses mathematical sleight of hand to falsely claim that rooftop solar drives costs up for non-solar customers.
To arrive at the accurate $2.3 billion savings, M.Cubed’s report analyzed the PUC report’s own raw data, but identified – and corrected – faulty logic and mathematical errors in the PUC’s methods.
Consumers purchase rooftop solar panels to save money on utility bills by generating their own electricity on-site. If the panels generate more power than consumers actually use, they can sell the excess back to the utility at a rate set by state net metering policies.
Utilities’ attacks on rooftop solar – and the math they use to back them up – assume that solar customers owe the utility for the electricity their panels generate. M.Cubed researchers rejected this assumption, noting that it’s essentially the same as saying that customers who use energy efficient appliances or insulation are “stealing” from the utility by buying less electricity. That faulty math added nearly $4 billion to the PUC’s cost-shift estimate.
Other accounting errors, like ignoring the fact that solar customers still pay utility bills, or overlooking key subsidies for low-income solar customers, made up most of the remaining total of the PUC’s false estimate.
California’s solar net metering compensation, once the best in the nation, was slashed in late 2022 by the PUC – which cited the cost-shift myth to justify the decision. Since the new policy went into effect in spring 2023, solar installations have cratered and many rooftop solar businesses have shrunk or closed.
A long series of reports in states all over the country have found no evidence to support the utility industry’s “cost shift” narrative. The M.Cubed report is one of the first to show how a large rooftop solar resource like California’s nation-leading 17 gigawatts can lower utility rates for everyone.
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