California is very ambitious about its 33% renewable energy aim for 2020 (after a 20% objective for 2010). Governor Jerry Brown calls for 8,000 megawatts from various large-scale wind and solar installations. The idea of a large state like California as a world leader in energy development appeals to those who want to promote more employment, new industries and technological leadership.
California's electricity sector is one of its largest sources of greenhouse emissions, contributing almost one quarter of the greenhouse gases, as you can see in Figure 1 below. The effort to reduce aggregate greenhouse gas emissions requires the state to reduce demand for energy through energy efficiency and switch from fossil fuel-based energy to cleaner renewable sources.
California greenhouse gas emissions 2002 - 2004; credit: California Air Resources Board
Firstly, 100,000 acres are needed to produce solar energy on degraded land, including the Mojave Desert. Ethan Elkind is the primary author of, "Harvesting Clean Energy" from law schools in both UCLA and UC Berkeley. In the text, he encourages farmers to use marginal cropland and any other degraded land. There are state regulations unfortunately that prevent non-agricultural use and state-wide definitions of marginal or impaired farmland need to be made. Ethan makes clear that these barriers to development need to be overcome with the need to:
"There's a whole mass of acres that aren't productive as agriculture lands, so it may be better to site renewable projects on them instead," says Michael Delbar of the California Rangeland Trust. Where water is short, it seems the best option could be to generate solar energy, rather than grow the few crops that tolerate low water availability.
Electricity sub-stations are unable to take on extra generation in areas where agricultural usage is the only light industry they are designed for. Areas with the least environmental and agricultural value and greatest sun exposure may lack access to transmission lines too.
Wildlife concerns are another obstacle to progress, as some hawk species have been able to adapt to crops such as alfalfa, but most species would be unable to use that land without crops. Several critically-endangered species live in field margins too. The San Joaquin kit fox and giant kangaroo rat are liable to be affected by a solar facility in the Panoche Valley, for example.