How California Solar Incentives Could Make A Bigger Impact

Despite being America’s clear solar leader, over the last several years California could have paid the same $2.2 billion to install way more than its 245,000 systems pumping out 2,365 megawatts — if it had simply given them away to the less well off.

Well, maybe San Diego County, whose rooftop solar installation data from 2007-2013 was crunched in Vanderbilt University and Sandia National Labs’ new study, partially funded by the U.S. Department of Energy and to be published in May’s Proceedings of the 14th International Conference on Autonomous Agents and Multiagent Systems. Employing a “data-driven agent-based modeling method” (jargon alert!) to analyze 8,500 solar projects in San Diego, the scientists extrapolated that the incentivized California Solar Initiative rebate program could have more significantly increased adoption if it had instead deployed “a carefully optimized program to provide systems to low-income households at little or no cost.”

“Despite the fact that policy makers have paid overwhelming attention to increasing the economic benefits by reducing costs to get people to adopt solar technology, our analysis indicates that this has much less effect than generally perceived,” explained Vanderbilt University computer science professor and study co-author Yevgeniy Vorobeychik. “That is what the data is telling us.”

That’s some high talk coming out of Vanderbilt’s home state, which doubled its installed solar capacity in 2014. That said, it still “has absolutely no renewables portfolio, no targets, nothing,” according to Solar Power Rocks’ report card for Tennessee, which got a D. With no statewide solar tax exemptions or credits, rebate programs, net metering or interconnection rules, Tennessee is staking quite the claim against the Golden State, which has few if any American peers when it comes to photovoltaics.

But its conclusion makes common sense, albeit few dollars: Giving pretty much anything away to the poor, in an age of skyrocketing income inequality, is often the easiest way to spread it around, given just how many more poor there are in the U.S. today than ever before.

That said, technically speaking, “the increasing prevalence of leasing” is somewhat to blame for CSI’s underwhelming performance, Vanderbilt University’s David Salisbury explained, because “it is the installers who receive the rebates and, according to the data, they have not been passing the incentive along to the homeowners.”

Unimpressed by CSI’s performance after sifting through San Diego’s six-year data, researchers instead turned their econometric attention to peer influence, which they claim is less well understood and leveraged. Using it, they created “a more effective subsidy scheme,” anchored in “the fact that the larger the number of solar installations in a person’s neighborhood, the more likely they are to decide to install a system.” What resulted was “an optimal program,” based on machine learning, that “could result in significantly greater adoption compared to the incentive approach,” and whose “relative advantage increased at higher budget levels.”

But for all of its complex machine learning, the study eventually arrived at a rather general human conclusion: If you really want the people to change their power, then you have to give them the power to do so. Now you just have to find a state that’s willing to do so for the love of solar, rather than money. If you find one in America, whether it’s California or Tennessee or any other state, please let us know.


This article appeared in Solar Energy