Every several years \u2014 sometimes just once a decade \u2014 when the rains come in just the right amounts and at just the right times, rare flowers speckle the Mojave Desert in California. Some, like the Barstow woolly sunflower, emerge from plants no larger than a thumbnail. They spring forth from seeds that have persisted in the dry soil for years, waiting for just such a sporadic event. <\/p>\n
In these brief \u201csuper-blooms,\u201d the desert floor looks \u201clike a carpet of wildflowers unfurled across the landscape,\u201d said Karen Tanner, a researcher at University of California, Santa Cruz. The quick flash of flora helps replenish the seeds for future generations. <\/p>\n
At other times, large sections of this deceptively fragile ecosystem look \u201clike the moon,\u201d Tanner said. Which, under the punishing sun, makes it seem like an ideal place to build large solar installations. Swaths of the desert, which spans four states, have already been converted to solar facilities, and more are on the way \u2014 in the Mojave and across the US. More than 4,600 square miles of land is projected to be covered by solar installations by 2030. <\/p>\n
A massive expansion of solar electricity is a crucial part of US plans to reach 80 percent renewable energy by the beginning of the next decade. This is essential to cutting carbon emissions and slowing catastrophic climate change \u2014 which poses a dire threat to plants and animals the world over, humans included.<\/p>\n
But the race to erect large-scale, maximally efficient solar operations could hurt local ecosystems if operators aren\u2019t careful. Based on her research, Tanner suspects many of these solar projects as they are traditionally executed are causing more local harm than some realize. She has spent nearly a decade closely studying \u2014 often on hands and knees with a magnifying glass \u2014 experimental solar plots in the Mojave, all located within six miles of four large solar installations. Her most recent findings, published earlier this year, have noted that solar panels changed the immediate microhabitat and had a detrimental impact on rarer plants, such as the Barstow woolly sunflower.<\/p>\n
One thing is clear to her: \u201cIt\u2019s just not enough to do one survey in one year and be like, \u2018Oh yeah, there\u2019s nothing here. Go ahead and install the infrastructure,\u2019\u201d she said. <\/p>\n
Solar doesn\u2019t have to be a zero-sum game that prioritizes either clean energy or<\/em> biodiversity, scientists told Vox. Many projects and studies are currently looking for ways that solar installations can better protect \u2014 and potentially even improve \u2014 local ecosystems, along with the bottom lines of operators and even nearby landholders like farmers. These solutions can be as simple as prioritizing native plants or picking a location that\u2019s already been disturbed by humans.<\/p>\n The darker side of solar<\/p>\n Solar installations, on the scale needed to supply power grids, are massive by necessity, transforming the lands where they\u2019re located into a new kind of built environment. They can alter everything from sun exposure to moisture to surface temperatures. This can have unintended and unexpected impacts on local plants, animals, and even the area\u2019s microbiome. <\/p>\n Photovoltaic panels shade the land while blocking some areas from rainfall and dousing others with heavy runoff. This changes the growing conditions for plants, with implications for other connected species. The other prominent form of solar, concentrating solar \u2014 in which mirrors focus the sun\u2019s rays \u2014 generates so much heat that it \u201ccan incinerate insects and burn the feathers of birds that fly through,\u201d Jeffrey Lovich, a research ecologist with the US Geological Survey who studies the environmental impacts of these installations, wrote to Vox. <\/p>\n In areas like the US Southwest, solar installations appear to contribute to bird mortality. Scientists aren\u2019t entirely sure why this is, but one prevailing idea, known as the \u201clake-effect\u201d hypothesis, is that migrating waterfowl making their way through the arid landscape mistake the installations for bodies of water and crash into them. <\/p>\n Large solar facilities in particular can also fragment important wildlife habitat or migration corridors via fences and landscape alteration, and can restrict gene flow for animal as well as plant populations. <\/p>\n Operators of these installations are generally keen to cut the costs of construction and maintenance, so most solar facilities replace the existing land cover with graded packed dirt, gravel, or mowed grass, further harming local biodiversity. \u201c\u2018Blade-and-grade\u2019 site prep that removes all vegetation clearly has a negative effect on biodiversity,\u201d Lovich said. He expects mowed grass would \u201cstress plant communities and the animals that use them.\u201d<\/p>\n Many of the impacts remain unknown. It\u2019s often difficult for researchers to gain access to solar facilities and the environmental data they collect \u2014 \u201ceven though the majority of facilities are situated on publicly owned lands,\u201d Lovich and colleagues noted in a 2017 paper. <\/p>\n But it\u2019s possible to dial down the potential harms of big solar farms. The type of solar infrastructure \u2014 whether concentrated solar or photovoltaic, and whether panels are fixed or rotating, high, or low \u2014 affects the potential downsides of large-scale installations. So does the nature of the landscape itself.<\/p>\n How solar can help native plants and crucial pollinators<\/p>\n Some solar operators are reimagining their facilities as prime protected habitats for native plants, bringing back key local species and potentially improving lands that humans have already disturbed. \u201cSolar can be a net benefit in terms of restoring a native habitat and improving ecosystem services, like storm water control and carbon storage and sequestration,\u201d said Leroy Walston, a landscape ecologist with Argonne National Laboratory who studies the relationship between renewable energy and the environment. <\/p>\n One in-vogue mitigation measure is pollinator-friendly foliage. At one experimental solar installation in Minnesota, pollinator-friendly plants helped boost energy yields a tad (by making the microclimate a touch cooler) and slightly reduced long-term maintenance costs (due to less-frequent mowing), according to a 2019 analysis from the Center for Business and the Environment at Yale University. The report also noted bigger wins: The plants helped reduce erosion, increasing groundwater stores and bolstering crop yields.<\/p>\n Experts have brought up concerns that solar operators will use a few flowers to green the image, but not the substance, of their operations. To help prevent this, some 15 states now have pollinator-friendly solar scorecards that aim to measure the actual impact of solar projects on the crucial creatures that carry pollen from plant to plant. <\/p>\n \u201cThey are voluntary, but they do help solar facilities to attain an objective certification that they\u2019re pollinator-friendly, that\u2019s been helpful to encourage some use of pollinator habitat at solar facilities,\u201d said Heidi Hartmann, a colleague of Walston who works as a program manager for land resources and energy policy at Argonne. For example, the California renewable electricity provider MCE is now asking its facilities on arable land to use \u201creasonable efforts\u201d to hit a certain score on these pollinator tallies.<\/p>\n Walston calls for an even broader approach to solar \u2014 one that focuses not only on bees and butterflies, but on native habitat restoration overall. Native plants are keenly tuned to the local environment, thriving in specific climate conditions, improving soil retention, and often benefiting the widest range of other area species, in ways non-native, flashy pollinator species might not.<\/p>\n Hartmann and Walston have modeled the impact of switching from maintained grass to native plantings. They found that in the US Midwest, native plants would bring in three times the number of pollinators. They\u2019d also boost the carbon storage potential of the soil by 65 percent and would be more effective, once established, at keeping weeds at bay, which could reduce the need for harmful herbicide use.<\/p>\n \u201cThe equation is complex,\u201d said Alyssa Edwards, vice president of environmental affairs at solar producer Lightsource BP, about the company\u2019s impact on local habitats. Lightsource advertises itself as protecting ecosystems and boosting biodiversity. \u201cPollinator habitat, considerations of seed availability, vegetation height, insurance requirements, fire risk, and cost all come into play. Not to mention that pollinator habitat may not be the right choice for all sites, as other initiatives may be more valuable contributions to sustainability.\u201d The company, a joint venture with the oil and gas giant BP, says it\u2019s working on various solar projects that incorporate pollinator habitat, conservation of short-grass prairie land, and even animal grazing.<\/p>\n Wildlife corridors are another way solar installations could help support biodiversity. But for large sites to become a part of corridors, they may require substantial adjustments to fencing and other built infrastructure (and even then, they\u2019d probably pose barriers to some larger species).<\/p>\n As more sites incorporate biodiversity as a benchmark, the devil is in the details. Tanner and others have found that solar panels can actually increase the number of plant species that grow beneath them, especially in harsh environments like the desert. However, some of these additional species are invasive or threaten to outcompete the smaller, rarer native ones that could tolerate such extreme desert conditions. <\/p>\n These kinds of wrinkles make it all the more important that scientists and operators actually measure their impact on ecosystems \u2014 that they\u2019re \u201cpausing for a moment and considering what sort of species we are considering that are making up the diversity,\u201d Tanner said. <\/p>\n Build solar on lands that humans have already messed with, one expert says<\/p>\n Solar operators tend to look for new sites based on sun and climate conditions, but also proximity to the existing power grid \u2014 and a utility company in the market for their energy. Scientists told Vox that firms should also look for places that humans have disturbed, because the local ecosystem may have less to lose.<\/p>\n Lovich suggests siting more solar farms on \u201cbrown fields, roof tops, abandoned agricultural fields, dry lakes, and even airports \u2014 where wildlife are unwanted.\u201d They\u2019re also well-suited for canals and human-made reservoirs, where they\u2019re sometimes called \u201cfloatovoltaics,\u201d not least because they can slow water loss by evaporation. These less-conventional arrangements may have higher up-front costs, but the eventual environmental costs will be lower. <\/p>\n Building on an ecologically sensitive site can also be costly. Take for example BrightSource Energy, which spent at least $56 million relocating threatened desert tortoises from its Ivanpah solar development site in the Mojave Desert. Although these efforts allowed the project to go through, scientists are still learning about the consequences. An early study found that the relocated tortoises needed more time and effort to settle into normal movement patterns, potentially exposing them to additional threats. But as Lovich pointed out, \u201csince tortoises are long-lived, results for the long term are not yet available.\u201d <\/p>\n Such experiences have not deterred other desert sun-seeking operations. \u201cSolar farms are operating or planned in excellent tortoise habitat affecting hundreds to thousands of tortoises,\u201d Lovich said. Simply moving the tortoises \u2014 pricey as it may be \u2014 is not a sure cure. \u201cTranslocation has a checkered history of success,\u201d he said. <\/p>\n Lovich is currently studying the impact of the Gemini Solar Project in Nevada, which would cover 11 square miles of publicly owned tortoise habitat and is home to hundreds of these long-lived, vanishing animals. For this project, the plan is to capture the animals, place them in a holding center for up to two years during construction, and then release them into the facility grounds \u201cto see how they fare,\u201d Lovich said. <\/p>\n \u201cAll energy sources will come with a cost to some wildlife,\u201d Lovich and his colleagues noted in a 2020 paper. \u201cThe best mitigation strategy is to avoid developing sensitive and pristine areas.\u201d <\/p>\n Other landscapes would not only tolerate solar farms, but could benefit from them. For example, a pollinator-friendly solar installation could add yield for farmers whose soy, citrus, almonds, cotton, or alfalfa needs some pollination help. More than 500 solar facilities already exist within easy buzzing-distance \u2014 less than a mile \u2014 from these crops in California, Massachusetts, and North Carolina, respectively, according to a 2018 study by Walston, Hartmann, and their colleagues. Nationally, more than 1,350 square miles of cropland would benefit if existing solar installations added pollinator-friendly plants, they concluded. <\/p>\n As solar has moved into lands that could otherwise be farmed, it has caused some tension with local residents. But solar farms and actual farms don\u2019t necessarily need to be in opposition. It\u2019s possible to co-locate solar and crops into \u201cagrivoltaic systems,\u201d which can feature grazing grass, corn grown for biogas, and even lettuce and tomatoes that may flourish under solar panels. Other crops could even be grown under semi-transparent solar panels.<\/p>\n Solar can protect plants and animals while it helps the planet<\/p>\n Redesigning solar developments \u2014 and steering them to the places where they won\u2019t cause harm \u2014 isn\u2019t easy. Maximizing energy output means finding locations with the right combinations of sun, temperature, wind, and humidity (one study pegged the best spots as croplands, grasslands, and wetlands) and packing solar-harvesting devices as densely as possible. All of these often work at cross-purposes with supporting a diverse range of plant and animal species.<\/p>\n Additionally, permits for these facilities are typically done at a very local level. (President Barack Obama had instructed these sorts of projects on federal lands to have a mitigation strategy \u2014 an order that President Donald Trump struck down his second month in office.) So it\u2019s a patchwork of different levels of regulations and approval processes, some of which are more in tune with thoughtful evaluation of sites and long-term impacts. There is \u201cmore education that can be done at local government levels,\u201d Hartmann said. <\/p>\n Without more thorough before-and-after research, we may remain in the dark about how these large facilities are changing the landscapes they cover. If site evaluations are performed over a relatively brief period of time \u2014 such as a single season in the run-up to the construction of a solar farm \u2014 operators could easily miss key aspects of biodiversity, like the Barstow woolly sunflower, which waits for just the right pattern of rare desert rain to emerge. <\/p>\n \u201cWe\u2019re just starting to scratch the surface and determine how different organisms are likely to respond\u201d to solar, said Tanner, the UC Santa Cruz researcher. For now, it behooves us to mess with their environment as little as possible, she noted, and to preserve as much as we can. \u201cEspecially in a context of climate change, we don\u2019t know what species are going to be able to pass through that aperture in the future.\u201d <\/p>\n As the world barrels toward climate catastrophe, scaling up carbon-neutral energy production as quickly as possible couldn\u2019t be more urgent. \u201cWe need all the help we can get, and we need to move quickly,\u201d Tanner said. On a planetary scale, clean electricity can help safeguard all species, and could arguably be worth the trade-off if it harms a few local species in the process. <\/p>\n But maybe there doesn\u2019t need to be a trade-off, Tanner suggested. \u201cI\u2019m not sure it\u2019s an either-or question,\u201d she said.<\/p>\n