A solar power plant in California’s Mojave Desert. Credit: Worklife Siemens/flickr
October 19th, 2015 By Bobby Magill Climate Central
Solar power development is big business in sunny California, fueled by low solar panel prices and the drive to reduce greenhouse gas emissions to tackle climate change. Some biologists, however, are growing concerned that the placement of new large-scale solar power plants in the Mojave Desert may harm the biological diversity found there. A study published Monday shows that solar power developers in California have been using mostly undeveloped desert lands with sensitive wildlife habitat as sites for new solar power installations rather than building on less sensitive, previously developed open lands. The study, by the Carnegie Institution for Science and Stanford University, shows the ecological footprint of solar power development could grow to more than 27,500 square miles — roughly the land area of South Carolina — if the U.S. were to adopt a more ambitious climate goal. When thousands of solar panels are built in undeveloped natural areas, the panels crowd out wildlife and destroy their habitat. “Solar takes out a lot of territory, right? It obliterates everything,” University of California-Santa Cruz ecologist Barry Sinervo, who is unaffiliated with the study, said. “There is as much plant biodiversity in the Mojave as there is in a redwood forest. The key part of this is, do we want to tile out the last largest wilderness area that we have, which is the Western desert?”
The Carnegie study found that of the 161 planned or operating utility-scale solar power developments in California, more than half have been or will be built on natural shrub and scrublands totaling about 145 square miles of land, roughly the land area of the city of Bakersfield, Calif. About 28 percent have been built on agricultural land and 15 percent have been built in developed areas. Areas that have already been developed and have little wildlife habitat would be better suited for solar development from an ecological standpoint, said study lead author Rebecca Hernandez, a postdoctoral fellow at University of California, Berkeley, and a former ecologist at the Carnegie Institution. Hernandez said she was surprised to find that nearly a third of solar development is occurring on former cropland, perhaps because farmers are shifting from growing crops to using their land to generate electricity. California’s devastating drought may be responsible for farmers’ shift to solar, something one of the study’s co-authors is researching in more depth. “We see that ‘big solar’ is competing for space with natural areas,” she said. “We were surprised to find that solar energy development is a potential driver of the loss of California’s natural ecosystems and reductions in the integrity of our state and national park system.” Finding ways to resolve conflicts between renewable energy development and ecosystem protection may be critical if the U.S. is to rely on more solar power to displace fossil energy to reduce greenhouse gas emissions. Assuming that 500 gigawatts of solar power may be needed to meet a future climate goal of reducing greenhouse gas emissions 80 percent below 1990 levels by 2050, Hernandez’s team found that a region of California roughly equal to the land area of South Carolina may be needed to accommodate all the new solar power plant development. … The study also does not account for increasing solar panel efficiency over time, something that is likely to reduce the amount of land needed to generate a megawatt of solar electricity….
Phil Taylor, E&E reporter
Published: Monday, October 19, 2015
Most commercial-scale solar energy projects in California are located within 6 miles of protected lands
such as inventoried roadless areas or critical habitat for federally protected species, according to a study released today by scientists at California universities.The study published in the Proceedings of the National Academy of Sciences examined 161 projects that have been planned, are under construction or are operating. Their proximity to protected areas “may exacerbate habitat fragmentation” with direct and indirect ecological consequences, it found. “A prevailing cause of degradation within protected areas is land use and land cover change in surrounding areas,” the study notes. “Protected areas are effective when land use nearby does not obstruct corridor use, dispersion capabilities, nor facilitate invasions of nonnative species through habitat loss, fragmentation, and isolation — including those caused by renewable energy development.”
It recommends land-use policies that encourage solar development in “human-impacted places” that comply with environmental laws to avoid “deleterious land cover change.”… Fewer than 15 percent of projects were located in “compatible” areas — defined by the study’s lead author as places that have previously been disturbed by humans, are sufficiently sunny and are located near existing energy infrastructure. About 19 percent of installations were in “incompatible” areas, due primarily to their lengthy distances to existing transmission….Today’s study found that nearly 30 percent of solar installations in California are sited in croplands and pastures, a sign that developers are increasingly gravitating toward farmland, such as in the Central Valley. But a greater number of projects are located in shrublands and scrublands, comprising about 93,000 acres of land-cover change.
Photovoltaic projects, which use panels like the ones installed on rooftops to convert sunlight directly into electricity, were concentrated particularly in the Central Valley and the interior of Southern California, while concentrated solar power projects, which use the sun to heat a liquid and power a turbine, were sited exclusively in inland Southern California, the study found.
Future project siting will have a major impact on biodiversity considering the scarcity of land and the vast space requirements of renewable energy, the study notes.
“Opportunities to minimize land use change include co-locating renewable energy systems with food production and converting degraded and salt-contaminated lands, unsuitable for agriculture, to sites for renewable energy production,” the study says. “Using unoccupied spaces such as adjacent to and on top of barns, parking lots, and distribution centers in agricultural areas is another win-win scenario.” The study found that 16 percent of photovoltaic and 44 percent of concentrated solar power installations were located in “incompatible” areas. Most of these plans were sited “far from transmission infrastructure.”…
Rebecca R. Hernandez et al PDF PNAS September 2015 doi: 10.1073/pnas.1517656112
Decisions humans make about how much land to use, where, and for what end use, can inform innovation and policies directing sustainable pathways of land use for energy. Using the state of California (United States) as a model system, our study shows that the majority of utility-scale solar energy (USSE) installations are sited in natural environments, namely shrublands and scrublands, and agricultural land cover types, and near (<10 km) protected areas. “Compatible” (≤15%) USSE installations are sited in developed areas, whereas “Incompatible” installations (19%) are classified as such owing to, predominantly, lengthier distances to existing transmission. Our results suggest a dynamic landscape where land for energy, food, and conservation goals overlap and where environmental co-benefit opportunities should be explored.
Decisions determining the use of land for energy are of exigent concern as land scarcity, the need for ecosystem services, and demands for energy generation have concomitantly increased globally. Utility-scale solar energy (USSE) [i.e., ≥1 megawatt (MW)] development requires large quantities of space and land; however, studies quantifying the effect of USSE on land cover change and protected areas are limited. We assessed siting impacts of >160 USSE installations by technology type [photovoltaic (PV) vs. concentrating solar power (CSP)], area (in square kilometers), and capacity (in MW) within the global solar hot spot of the state of California (United States). Additionally, we used the Carnegie Energy and Environmental Compatibility model, a multiple criteria model, to quantify each installation according to environmental and technical compatibility. Last, we evaluated installations according to their proximity to protected areas, including inventoried roadless areas, endangered and threatened species habitat, and federally protected areas. We found the plurality of USSE (6,995 MW) in California is sited in shrublands and scrublands, comprising 375 km2 of land cover change. Twenty-eight percent of USSE installations are located in croplands and pastures, comprising 155 km2 of change. Less than 15% of USSE installations are sited in “Compatible” areas. The majority of “Incompatible” USSE power plants are sited far from existing transmission infrastructure, and all USSE installations average at most 7 and 5 km from protected areas, for PV and CSP, respectively. Where energy, food, and conservation goals intersect, environmental compatibility can be achieved when resource opportunities, constraints, and trade-offs are integrated into siting decisions.