- Study found that most big solar installations in California were located in biologically-sensitive desert lands — comprising of scrublands and shrublands — for installations, covering about 145 square miles.
- Nearly one-third of the big solar installations were located in crop lands, the team found.
- Study also identified around 8,500 square miles of areas in less-sensitive, already-developed land that is compatible for solar energy installations.
Solar power generation is booming in the U.S. In 2014, for example, big solar facilities or the utility-scale solar energy installations generating at least 1 megawatt (MW) — enough to power around 164 homes — grew by 38 percent from 2013, according to the Solar Energy Industry Association.
But big solar farms need vast amounts of land. And this increasing demand for land is threatening natural areas and biodiversity, warns a new study published in the Proceedings of the National Academy of Sciences.
“Our study, which focuses on California, shows that utility-scale solar energy development can be a driver of land-use and land-cover change, which is a source of greenhouse gas emissions itself,” Rebecca R. Hernandez, lead author now at University of California, Berkeley, said in a statement. “We see this happening if solar energy power plants are sited in natural habitats, in lieu of areas already impacted by humans — such as on commercial rooftops or over parking lots.”
California leads U.S.’s rush for clean energy. In 2015, California became the first state in the country to generate over five percent of its electricity from utility-scale solar energy farms.
To investigate how such utility-scale solar energy (USSE) installations impact changes in land-use, Hernandez and her colleagues evaluated 161 planned, under-construction, and operating installations in the state of California.
The team found that instead of favoring less-sensitive, already developed lands, most big solar power farms were using desert lands — comprising of scrublands and shrublands — for installations, covering about 375 square kilometers (145 square miles).
These desert areas are rich in biodiversity, the authors write. “California’s shrublands and scrublands comprise, in part, the California Floristic Province, a biodiversity hot spot known for high levels of species richness and endemism and where 70% or more of the original extent of vegetation has been lost due to global environmental change- type threats, including land cover change,” they add.
Such seemingly “unproductive” scrub- and shrublands have numerous ecosystem services. These include “diverse recreational opportunities, culturally and historically significant landscapes, movement corridors for wildlife, groundwater as a drinking source, and carbon (sequestration), which may also be adversely impacted by land cover conversion,” the authors write.
For example, several solar power plants are currently installed in California’s Mojave desert. This desert has a vibrant ecosystem, and is home to around 2,000 species of plants, and several threatened species, such as the desert tortoise (Gopherus agassizii) and Owen’s pupfish (Cyprinodon radiosus).
“Solar energy in developed areas, or for example on contaminated lands, would have great environmental co-benefits, but this is not what is being emphasized,” Hernandez said in another statement. “Instead, we see that ‘big solar’ is competing for space with natural areas. Knowing this is vital for understanding and creating predictions of a rapidly changing global energy landscape.”
The team was surprised to find that nearly one-third of the big solar installations were in crop lands. Increasing pressure from California’s drought could have pushed farmers to shift to harvesting solar energy, researchers write.
The study also identified around 8,500 square miles of areas in already-developed land — like parking lots and rooftops — that is compatible for solar energy installations.
“We can’t just throw them (solar installations) across a landscape and say biological diversity be damned,” Cameron Barrows from the University of California-Riverside, told Climate Central. “We have to find the right places to put these things… There are biological riches that are part of our natural heritage that we don’t want to lose.”
- Hernandez RR, Hoffacker MK, Murphy-Mariscal ML, Wu GC, and Allen MF (2015) Solar energy development impacts on land cover change and protected areas. Proceedings of the National Academy of Sciences. Doi:10.1073/pnas.1517656112