Wild solar and equitable grids

Wild solar and equitable grids
UC Davis professor Rebecca R. Hernandez (far right), graduate students Noah Krasner and Yudi Li (left), and Kathleen Ave of the Sacramento Municipal Utility District visit the Rancho Seco II solar site to test seeding the ground with native plants. Image credit: David Palmer

By Caroline Champlin

If you’re looking for something to do on the next sunny day in California, here’s a nerdy suggestion: check out some data. You can jump on the Cal ISO website to see how much of the state’s energy is coming from renewables like solar and wind, minute by minute. On a clear day, it could be around 75 percent clean energy.

Sophie Parker, director of science for The Nature Conservancy, loves to check on these statistics. Over the years, she’s seen the numbers edging ever closer to the state’s goal of 100 percent clean power by 2045. “We’re in the middle of this huge clean energy transition. It’s a question of how,” Parker said.

The University of California, in collaboration with the state of California, has awarded grants totaling $4 million to two projects to address that question. As renewable energy development accelerates, these projects seek to ensure the new infrastructure is equitable, ecologically responsible, and ready to withstand the changing climate. The grants are part of a larger climate resiliency campaign that includes over $80 million in California Climate Action Seed and Matching Grants awarded by the UC Office of the President.

Wild solar and equitable grids
The UC Davis Solar Farm is essentially Dr. Hernandez’s lab. There, her team tests how well different plant assortments, like this California Prairie Wildflower Seed mix, grow amid the solar panels.

One of the grant-funded projects, led by a team at UC Davis, will explore alternatives to conventional solar farms—think wildflower meadows, not just panels on dirt lots. They will test the science and economics of “wild solar,” an emerging field that seeks to preserve biodiversity by incorporating habitat restoration, water storage, and even agriculture on solar sites. 

Partners on the project include renewable energy developers, energy non-profits, the Sacramento Municipal Utility District, U.S. Geological Survey, and Sophie Parker’s Nature Conservancy team. “In the American West, there’s been this perceived green-on-green conflict between biodiversity conservation, protecting lands and waters, and renewable energy development,” Parker said. “We have to think holistically about how we can address these challenges together.” 

In a similar vein, researchers from UC San Diego received a Climate Action grant to broaden access to California’s electricity grid. The team will conduct a statewide survey on electric vehicles, rooftop solar, and battery storage adoption. With that information, they’ll model scenarios using those resources to ensure the power stays on in disadvantaged communities during blackouts triggered by extreme weather or wildfires.

Wild solar and equitable grids
Floating solar panels atop water bodies such as canals can avoid destroying habitat to build solar farms while minimizing evaporation. Image credit: Rebecca Hernandez

Floating ideas for ecologically sound solar energy

UC Davis professor Rebecca R. Hernandez remembers the start of the solar energy boom in California. She was a researcher working in the Mojave, watching desert all around her get cleared for solar sites. 

“Wow, this is really good that we’re developing so much renewable energy,” Hernandez remembers thinking, “But gosh, it’s kind of odd that it’s being developed in places where we knew there was a lot of biodiversity.”

That tension between renewable infrastructure and native habitats ended up inspiring Hernandez’s doctorate. Her work highlighted permanent damage solar projects were inflicting on California ecosystems—sometimes to the chagrin of the renewable energy industry.

“I got some angry emails,” Hernandez said. “I thought to myself, ‘Do I really want to be doing work that is just focused on scoping out every bad thing that’s happening from ground-mounted solar energy developments?’”

Hernandez imagined a peaceful meeting between the worlds of ecology and engineering. “Can you add some wildness to something that is industrial?” she wondered.

Hernandez wished she could offer developers a menu of sorts, full of solar farming techniques that could enhance landscapes while still generating the clean power needed to address climate change. Testing a menu of solar solutions is the focus of her climate action grant project, which was awarded $2 million by the University of California. 

Wild solar and equitable grids
UC Davis PhD student Yudi Li measures test plants growing on a solar site.

The project will investigate three “wild solar” entrées: ecovoltaic, agrivoltaic, and floatovoltaics. 

An ecovoltaic system restores habitat on solar sites, like planting native flowers under panels or facilitating wildlife corridors between them. This idea comes with big questions, like whether plants and animals can interact successfully and safely with solar infrastructure, but offers opportunities as well. Growing light-colored native plants, for example, could reflect sunlight back onto the panels, generating more energy—and revenue—for operators.

Agrivoltaic systems grow crops like wheat under panels. According to Hernandez, as water gets more expensive, pivoting from crops like almonds to solar arrays is already a temptation for California landowners. She sees exploring the economics of merging solar and crop farming as an investment in California’s agricultural future.

Floating solar deploys PV panels on rafts in manmade water bodies such as the California Aqueduct. The panels act like a useful lid, keeping evaporation down while generating energy. Plus, solar power from the panels could power pumps and other machinery running those water systems—forming a nice closed loop.

The long-term goal of the project is the creation of UC Wild Solar, a cooperative network of researchers and industry stakeholders testing these methods at solar site laboratories across the state. Hernandez and colleagues with similar interests in minimizing environmental impacts while maximizing the availability of clean power have banded together to establish the UC Davis Wild Energy Center.

“How can we align these goals for both protecting species, some of which are found nowhere else in the world, and also develop energy in a way that doesn’t commit the same atrocities that have been made in the past, mostly at the hand of the fossil fuel industry?” Hernandez said. 

The project begins this year by recording interactions between species and solar infrastructure. The findings will be presented at a stakeholder conference.

Wild solar and equitable grids
Professor Patricia Hidalgo-Gonzalez of UC San Diego is gathering the information needed to make the clean power grid more resilient and available to currently underserved and vulnerable communities. Image credit: NASA

Ensuring clean energy reaches underserved communities

Fire season in California has come to mean the looming possibility of power blackouts. When energy consumption is low, power lines can stay cool, reducing the risk of sparks near flammable vegetation.

Patricia Hidalgo-Gonzalez, a mechanical and aerospace engineering professor at UC San Diego, is proud of how Californians have dodged blackouts by lowering their AC or shifting their schedules to avoid early evening peaks in demand. 

But according to Hidalgo-Gonzalez, flexibility is a privilege. “When we think about vulnerable communities, they don’t have the choice to say ‘I’ll do laundry at noon’ because they’re working somewhere,” Hidalgo-Gonzalez said.

When blackouts do happen, underserved communities are more likely to stay in the dark. “A lot of the wealthier communities were able to invest in diesel generators at home,” Hidalgo-Gonzalez said. “But there are communities that don’t have any access to anything, and they just had to survive without electricity for however many hours or days.”

Hidalgo-Gonzalez was awarded nearly $2 million to research this equity problem over the next four years. She’ll have help from partners at UC Santa Barbara, UC Berkeley, Lawrence Berkeley National Laboratory, and the National Renewable Energy Laboratory. 

As the state transitions to renewable energy, it will need to identify how to store that power. To Hidalgo-Gonzalez, it’s an opportunity to avoid repeating past mistakes. Her project will work to ensure new infrastructure is equitable from the start.

Researchers will kick off the project this year by surveying Californians about how likely they are to adopt “grid edge” technology—infrastructure where the utility grid meets consumer property, like rooftop PV panels, local battery storage, or electric vehicles. 

Such backup power systems would make disadvantaged communities more resilient during blackouts. They could even earn residents money by enabling the sale of extra energy to utilities. 

Wild solar and equitable grids
Researchers will survey Californians about how likely they are to adopt technologies like photovoltaic panels, battery storage, or electric vehicles. Their findings will help inform the design of an equitable clean energy grid. Image credit: Alex Green/Pexels

Considering the number of renters in the state, Hidalgo-Gonzalez says disadvantaged communities might benefit from a co-op system that puts solar panels on a community center or other local hub, rather than an apartment roof. That’s why she plans to engage directly with community groups.

“We cannot come up with a technical solution that doesn’t make sense for the community. It should be informed from their side,” she said. 

A team at UC Santa Barbara, including environmental studies professor Grace Wu, will lead the online survey. By oversampling people living in California’s underserved communities, they hope to gain a thorough understanding of barriers to adopting electrified technology and design incentives to support them.

“I am most excited to see the social science being integrated into a traditionally very technical approach to these types of questions,” Wu said. “It’s fairly rare for social scientists to collaborate with engineers.”

With the survey data, researchers can model what the state’s energy grid could look like in 2035. Then, they will shock that model with hypothetical extreme weather and wildfires to predict how the grid would fare.

The goal is to bring this analysis to grid operators and regulators like the California Public Utilities Commission. The grant project can inform their policies and ideally help make the state’s renewable energy equally available to all residents.

“I think more democratization of this type of analysis is important.” Hidalgo-Gonzalez said. “What we want to do with this grant is try to design a grid that’s going to be reliable 100 percent of the time.”

In true interdisciplinary spirit, Hidalgo-Gonzalez hopes to include a conservation perspective on her project to align biodiversity goals with energy grid development. Luckily, she knows just the person at UC Davis to ask.