Environmental Groups Call for More Rooftop Solar in California

Going big on rooftop solar could spare hundreds of thousands of acres of land from being overrun by panels, researchers say.

solar rooftop in california

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Prioritizing rooftop solar over large solar farms will accelerate California’s decarbonization efforts while helping protect environmentally sensitive areas and endangered species, a new report says.

The administration of Gov. Gavin Newsom has pledged to move the country’s most populous state to a zero-carbon power system by 2045, which will require huge investments in wind generation but especially in solar, given the state’s plentiful solar resources

However, many solar projects face strong opposition from local residents and environmentalists, because although solar arrays produce carbon-free electricity, they need swathes of land — especially very large facilities, which can have more than 1 million solar modules. 

People living near areas suited for utility-scale solar farms fear that solar arrays will ruin their rural landscapes, while environmentalists have long expressed concerns about the threats to vulnerable species of plants and animals, like the California desert tortoise and the bighorn sheep.

For instance, Crimson Solar and Desert Quartzite, two industrial solar farms planned for the California desert, face fierce opposition from environmentalists who say that energy companies should seek to install solar arrays on vacant urban land and landfills instead of on pristine desert landscapes.

According to the Desert Sun, there are approximately 12 solar projects constructed, in development, or pending approval for desert areas in California. Altogether, these projects will cover over 30,000 acres—more than twice the Island of Manhattan.

But a new report by the Frontier Group and the Environment California Research & Policy Center argues that “going big” on rooftop solar could spare hundreds of thousands of acres of land from being overrun by panels, which would help the Newsom administration achieve its goal of protecting at least 30% of California’s natural land and coastal water areas by 2030.

California officials foresee that to achieve its clean energy goals, the state will need to nearly quadruple rooftop solar capacity to 39 gigawatts by 2045 but the report argues that California should aim for 129 gigawatts, more than three times as much. 

“​​Each 1 gigawat of rooftop solar instead of utility-scale solar potentially avoids the conversion of almost 5,200 acres of land, an area slightly smaller than the city of Monterey,” the report says.

To back this argument, the report cites a 2016 analysis by the National Renewable Energy Laboratory, which found that California could potentially meet three-quarters of its electricity needs with rooftop solar in residential and commercial buildings, as well as parking lots and other urban areas. 

Rooftop has many other advantages. For instance, solar arrays can be installed in three months on average while the construction of large-scale solar farms can easily take years. 

On top of that, rooftop solar does not require transmission infrastructure, which further reduces its environmental impact and, in combination with battery storage, can provide buildings and communities with power during emergencies or blackouts. 

Strong Growth

Rooftop solar, which provided 7.5% of all the electricity generated in the state in 2019, has seen impressive growth in the past few years, doubling capacity every two or three years since 2006. Already in 2019, more than 1 million Californian roofs featured solar panels. 

That solid growth has occurred in large part because California has been a strong advocate for rooftop solar. In 2019, the state adopted building codes requiring new small residential buildings to install solar roofs.

But rooftop solar growth is now being challenged by corporate interests. The three largest utilities in California—PG&E, SoCal Edison, and SDG&E—want to reduce the payments that solar panel owners receive for the excess energy they send to the grid, and impose additional fees. 

“If those efforts succeed, growth of rooftop solar could very well grind to a halt–forcing California to get more of its power from large-scale sources of renewable energy, many of them in ecologically sensitive areas,” the authors of the report said in a statement.

The report also calls on California to accelerate solar energy adoption on affordable and rental housing, by ensuring that solar owners who pay reduced rates “are fully compensated for the power they provide to the grid.”

In addition, cities and counties should establish user-friendly online permitting systems to ensure that small onsite solar projects are approved quickly.