By Roy L Hales
November 13, 2015 (San Diego’s East County) - The joint study from Stanford University and UC Riverside reads like a report card. The authors recognized that, “solar energy has one of the greatest climate change mitigation potentials” of all renewable energy sources. It can play a leading role in helping the United States reach its’ goal of reducing emissions to 80% of 1990 greenhouse gas emissions by 2050. This would require covering a great deal of land surface. Using current technology, close to 71,428 square kilometres (44,383 sq. miles), or an area roughly comparable to South Carolina, could be covered with panels. Rebecca R. Hernandez et al examined more than 160 sites in California to find out how utility scale solar impacts the land.
U.S. Policy is the Reverse of Europe’s They found much that needs to be changed.
Current regulations and policies “deemphasized” solar development “within the built environment and near population centers in favor of development within shrublands and scrublands.”
This is the reverse of the situation in Europe. In Germany, for example, 90% of the solar installations are in developed lands. An Italian study found that 2/3 of US installations are in “environmentally unsuitable” lands “with adverse implications for land cover change-related CO2 emissions.”
“A large portion” of the “incapable” Californian installations they studied are “sited far from existing transmission infrastructure.” This is both expensive and “difficult to site due to social and environmental concerns.”
” … Development decisions may overlook environmental resources unprotected by policies but valued by interest groups [e.g., important bird areas, essential connectivity areas, vulnerability of caliche (i.e., mineralized carbon) in desert soils, biodiversity hot spots, percent habitat loss].”
Scrublands contain “diverse recreational opportunities, culturally and historically significant landscapes, movement corridors for wildlife, groundwater as a drinking source, and carbon (sequestration) …”
These are “biologically rich” areas, “known for high levels of species richness,” which have already lost “70% or more of the original extent of vegetation … due to global environmental change- type threats, including land cover change.”
In addition to sites on scrubland and scrubland, almost a third of the installations were on agricultural land where, “The growing demand for food, affordable housing, water, and electricity puts considerable pressure on available land resources, making recent land use decisions in this region a noteworthy case study for understanding the food– energy–water nexus that should be explored.”
Hernandez et al also found that there are many “compatible” utility scale solar installations in California. They range between 20 MW and 200 MW in capacity and, aside from the much publicized facility in Yolo County, are “located within the Central Valley and inland southern California regions.”
Though the report does not specifically mention brownfield areas, the EPA previously identified over 10,000 U.S. sites with the potential to install a 300-kilowatt solar array or greater. These are contaminated areas where there would be no environmental damage and presumably few conflicts with local residents.
Hernandez et al did recommend urban solar:
“Siting USSE installations in places already impacted by humans (e.g., parking lots, rooftops) reduces the likelihood that adverse environmental impacts will occur and can exceed generation demands for renewable energy goals in places with moderate- to high-quality solar resources, including California.”
PV solar installations within developed areas “could meet California’s total energy demand 4.8 … times over …” Concentrated Solar Power could produce 2.7 times the state’s needs.
Illustrations: Fig. 2. Number of photovoltaic (PV) and concentrating solar power (CSP) installations (planned, under construction, operating) by land cover type in California; represented in order of most installations to least for both technologies. - Solar energy development impacts on land cover change and protected areas, Rebecca R. Hernandez et al;
Ivanpah electric power generation station by Bill & Vicki T via Flickr (CC BY SA, 2.0 License)