In the late 2000s, small-aircraft pilots gliding above the Napa countryside began to notice an odd, glassy glint reflecting off a tennis-court-size patch of land between vineyards. Large solar arrays were less common back then, but the solar panels themselves likely weren’t the reason planes doubled back, flying low, for a closer look: it was their placement in the middle of a pond.
Floating solar panels, like the ones Napa’s Far Niente winery finished installing in 2009, could be a real windfall for a watery Bay-Delta region seeking carbon-free energy. Secured to buoyant platforms or pontoons, low over the water’s surface and at a slight angle, the panels can cover a large area without competing with agriculture or housing for primo sun-drenched land. They slow evaporation from the water sources they cover that might otherwise dwindle to nothing in the summertime. And of course, they make electricity without emitting the planet-heating gases that are deepening droughts, worsening wildfires, and drowning coastlines in California.
With the technology gaining traction, it may not be long before floating solar panels are soaking up the sun atop bodies of water large and small throughout the Delta and San Francisco Estuary. But which sorts of places are best suited for this emerging approach to solar energy?
“It’s that old story of location, location, location,” says Rebecca Hernandez, an associate professor of ecology and earth sciences at UC Davis who studies interactions between energy infrastructure and ecosystems.
Brewers blackbirds perch on the panels during an evening survey at Far Niente Winery, with spotting scope in foreground. Photo: Jocelyn Rodriguez
Drawing a parallel to land-based solar, she rattles off two examples of siting with vastly different ecological implications: building solar panels on the roof of a parking garage, or in a natural desert scrubland. It’s no hypothetical that California would develop large solar farms on the latter, despite an abundance of sunny parking-garage roofs going unused. Hernandez worries that floating solar could be destined for the same kind of clash in the coming years, and potentially impact vulnerable aquatic and avian species and ecosystems in the race to build renewable energy if siting decisions are not made carefully.
“Birds don’t know what [it] is,” she adds. “This is the first time in their evolutionary history that they’ve encountered this really weird, water-looking-like, but very hard material … on the pond that they used to swim across or fly across.” Capping a pond with sheets of gleaming silicon and glass could also impact its ecology by altering water temperature and circulation and affecting the local food web.
Floating solar proponents might point out that the same ecosystems and species that might be disrupted by floating solar arrays also face disruption from a warming and unchecked climate. Carbon-free energy like solar power is a key part of limiting that warming, and it’s hard to argue against building more of that energy, and fast.
Complicating the decision-making process about where floating solar should go is that California’s aquatic spaces, much like its lands, rarely exist in neat bins of “natural” or “human-made.” Constructed reservoirs can still support native species and offer cherished recreational opportunities to human communities, and even a more heavily managed site like a wastewater treatment pond can support wildlife. The small Sonoma County town of Healdsburg boasts the nation’s largest floating solar array on its treatment ponds, and Canadian geese there have staked the edge of the array nearest the open water as their own territory—marked by generous splatters of white excrement along those panels.
“They’re year-long residents, and before we put the solar in, they would hang out on this roadway,” says Healdsburg utility director Terry Crowley. “So we’re actually kind of happier that they’re on that part of it.”
Elsewhere, Hernandez says her team has observed some astonishing, even delightful, interactions between wildlife and floating panels. At a Florida research site, otters will play among the arrays while herons strategically hunt off the floats.
Tri-colored heron at the Orlando Utilities Commission FPV site in Florida. The herons are regularly observed using the perimeter of floating solar arrays to stalk prey in deeper waters than they otherwise would be able to along the shore. Photo: Jocelyn Rodriguez
And Greg Allen, a Far Niente winemaker and the mastermind behind the winery’s first-in-the-world floating solar project, says he still hears frogs chorusing from the irrigation pond that has now been covered with solar panels for well over a decade.
There are still plenty of places floating solar can go that align with the analogue of a parking garage roof more than an undisturbed desert. California’s concrete-walled aqueduct system and many wastewater treatment and industrial cooling ponds could be places to start making power and saving water, with minimal disturbance to wildlife habitats.
If floating solar construction accelerates around the San Francisco Estuary, now may be the best and only moment to avoid repeating mistakes made, from an ecological perspective, in the rush to build large solar farms on land. A more cautious approach needn’t require stalling floating solar development. But it would likely prioritize areas with less consequential habitat first, by learning where the watery equivalents of “parking garages” are and starting with setting solar panels afloat there. In the meantime, scientists can learn more about whether, and where, more sensitive watery habitats and floating solar can best coexist in peace.
“There is no data out there right now,” warns Hernandez. “We are taking a picture of this moving train as it speeds past us.”
Sierra Garcia is an interdisciplinary marine scientist and environmental writer with a focus on oceans, climate, and communities. She is Estuary's multiplatforms editor, and does outreach and planning as well as some reporting for the magazine. Her work has appeared in publications serving a wide range of audiences, including Grist, JSTOR Daily, and the Oxford Climate Review. She was proudly born and raised in Monterey County.
Our magazine’s media motto for many years has been “Where there’s an estuary, there’s a crowd.” The San Francisco Estuary is a place where people, wildlife, and commerce congregate, and where watersheds, rivers and the ocean meet and mix, creating a place of unusual diversity. In choosing to tell the...
Ever since the state and federal water projects were built in the 1930s and 1940s, California has captured snowmelt in foothill reservoirs, and moved the fresh water from dam releases and river outflows to parched parts of the state via aqueducts hundreds of miles long. A convoluted system of ancient...
Though the Clean Water Act did an amazing job of reducing wastewater and stormwater pollution of the San Francisco Estuary, some contaminants remain thorny problems. Legacy pollutants like mercury washed into the watershed from upstream gold mining, PCBs from old industrial sites, and selenium from agricultural drainage in the San...
Hothouse Earth
By Ariel Rubissow Okamoto
Photo by Megan Nguyen
Nothing could be stranger than sitting in the dark with thousands of suits and heels, watching a parade of promises to decarbonize from companies and countries large and small, reeling from the beauties of big screen rainforests and indigenous necklaces, and getting all choked up.
It was day two of the September 2018 Global Climate Action Summit in San Francisco when I felt it.
At first I wondered if I was simply starstruck. Most of us labor away trying to fix one small corner of the planet or another without seeing the likes of Harrison Ford, Al Gore, Michael Bloomberg, Van Jones, Jerry Brown – or the ministers or mayors of dozens of cities and countries – in person, on stage and at times angry enough to spit. And between these luminaries a steady stream of CEOs, corporate sustainability officers, and pension fund managers promising percentages of renewables and profits in their portfolios dedicated to the climate cause by 2020-2050.
I tried to give every speaker my full attention: the young man of Vuntut Gwichin heritage from the edge of the Yukon’s Arctic National Wildlife Refuge who pleaded with us not to enter his sacred lands with our drills and dependencies; all the women – swathed in bright patterns and head-scarfs – who kept punching their hearts. “My uncle in Uganda would take 129 years to emit the same amount of carbon as an American would in one year,” said Oxfam’s Winnie Byanyima.
“Our janitors are shutting off the lights you leave on,” said Aida Cardenas, speaking about the frontline workers she trains, mostly immigrants, who are excited to be part of climate change solutions in their new country.
The men on the stage, strutting about in feathers and pinstripes, spoke of hopes and dreams, money and power. “The notion that you can either do good or do well is a myth we have to collectively bust,” said New Jersey Governor Phil Murphy whose state is investing heavily in offshore wind farms.
“Climate change isn’t just about risks, it’s about opportunities,” said Blackrock sustainable investment manager Brian Deese.
But it wasn’t all these fine speeches that started the butterflies. Halfway through the second day of testimonials, it was a slight white-haired woman wrapped in an azure pashmina that pricked my tears. One minute she was on the silver screen with Alec Baldwin and the next she taking a seat on stage. She talked about trees. How trees can solve 30% of our carbon reduction problem. How we have to stop whacking them back in the Amazon and start planting them everywhere else. I couldn’t help thinking of Dr. Seuss and his truffala trees. Jane Goodall, over 80, is as fierce as my Lorax. Or my daughter’s Avatar.
Analyzing my take home feeling from the event I realized it wasn’t the usual fear – killer storms, tidal waves, no food for my kids to eat on a half-baked planet – nor a newfound sense of hope – I’ve always thought nature will get along just fine without us. What I felt was relief. People were actually doing something. Doing a lot. And there was so much more we could do.
As we all pumped fists in the dark, as the presentations went on and on and on because so many people and businesses and countries wanted to STEP UP, I realized how swayed I had let myself be by the doomsday news mill.
“We must be like the river, “ said a boy from Bangladesh named Risalat Khan, who had noticed our Sierra watersheds from the plane. “We must cut through the mountain of obstacles. Let’s be the river!”
Or as Harrison Ford less poetically put it: “Let’s turn off our phones and roll up our sleeves and kick this monster’s ass.”
4th California Climate Change Assessment Blues
by Isaac Pearlman
Since California’s last state-led climate change assessment in 2012, the Golden State has experienced a litany of natural disasters. This includes four years of severe drought from 2012 to 2016, an almost non-existent Sierra Nevada snowpack in 2014-2015 costing $2.1 billion in economic losses, widespread Bay Area flooding from winter 2017 storms, and extremely large and damaging wildfires culminating with this year’s Mendocino Complex fire achieving the dubious distinction of the largest in state history. California’s most recent climate assessment, released August 27th, predicts that for the state and the Bay Area, we can expect even more in the future.
The California state government first began assessing climate impacts formally in 2006, due to an executive order by Governor Schwarzenegger. California’s latest iteration and its fourth overall, includes a dizzying array of 44 technical reports; three topical studies on climate justice, tribal and indigenous communities, and the coast and ocean; as well as nine region-specific analyses.
The results are alarming for our state’s future: an estimated four to five feet of sea level rise and loss of one to two-thirds of Southern California beaches by 2100, a 50 percent increase in wildfires over 25,000 acres, stronger and longer heat waves, and infrastructure like airports, wastewater treatment plants, rail and roadways increasingly likely to suffer flooding.
For the first time, California’s latest assessment dives into climate consequences on a regional level. Academics representing nine California regions spearheaded research and summarized the best available science on the variable heat, rain, flooding and extreme event consequences for their areas. For example, the highest local rate of sea level rise in the state is at the rapidly subsiding Humboldt Bay. In San Diego county, the most biodiverse in all of California, preserving its many fragile and endangered species is an urgent priority. Francesca Hopkins from UC Riverside found that the highest rate of childhood asthma in the state isn’t an urban smog-filled city but in the Imperial Valley, where toxic dust from Salton Sea disaster chokes communities – and will only become worse as higher temperatures and less water due to climate change dry and brittle the area.
According to the Bay Area Regional Report, since 1950 the Bay Area has already increased in temperature by 1.7 degrees Fahrenheit and local sea level is eight inches higher than it was one hundred years ago. Future climate will render the Bay Area less suitable for our evergreen redwood and fir forests, and more favorable for tolerant chaparral shrub land. The region’s seven million people and $750 billion economy (almost one-third of California’s total) is predicted to be increasingly beset by more “boom and bust” irregular wet and very dry years, punctuated by increasingly intense and damaging storms.
Unsurprisingly, according to the report the Bay Area’s intensifying housing and equity problems have a multiplier affect with climate change. As Bay Area housing spreads further north, south, and inland the result is higher transportation and energy needs for those with the fewest resources available to afford them; and acute disparity in climate vulnerability across Bay Area communities and populations.
“All Californians will likely endure more illness and be at greater risk of early death because of climate change,” bluntly states the statewide summary brochure for California’s climate assessment. “[However] vulnerable populations that already experience the greatest adverse health impacts will be disproportionately affected.”
“We’re much better at being reactive to a disaster than planning ahead,” said UC Berkeley professor and contributing author David Ackerly at a California Adaptation Forum panel in Sacramento on August 27th. “And it is vulnerable communities that suffer from those disasters. How much human suffering has to happen before it triggers the next round of activity?”
The assessment’s data is publicly available online at “Cal-adapt,” where Californians can explore projected impacts for their neighborhoods, towns, and regions.
The results are alarming for our state’s future: an estimated four to five feet of sea level rise and loss of one to two-thirds of Southern California beaches by 2100, a 50 percent increase in wildfires over 25,000 acres, stronger and longer heat waves, and infrastructure like airports, wastewater treatment plants, rail and roadways increasingly likely to suffer flooding.