. 2015.
With the increasing desire to fight global climate change, increasing the use of renewable energy resources such as solar, is a challenge to the traditional model of utility-scale solar energy installations. Until now, studies quantifying the effects on land-cover change and analyses of impacts on protected areas near solar facilities have been limited.
A study published in the Proceedings of the National Academy of Sciences, assessed the siting impacts of 161 existing, under construction, and planned utility-scale solar energy facilities in California. Utility-scale solar energy facilities generate at least 1 megawatt, which is enough to power approximately 165 homes.
The researchers found that a majority of sites are located in natural California shrub- and scrublands covering about 145 square miles:
- 28% are in croplands and pastures.
- Less than 15% are in developed areas.
- Around 19% are in areas far from existing transmission infrastructure, which has adverse economic, energetic, and environmental consequences.
This study included two kinds of solar technologies, photovoltaics (PV), which use semiconductors, and concentrating solar power (CSP), which use mirrors to focus the sun’s rays for generating steam.
In analyzing impacts on protected areas, the researchers calculated the proximity of solar installations to them. The fact that nearly 20% of solar facilities were far from transmission infrastructure means that the energy must travel farther and therefore have greater energy losses, cost more to build, and new transmission corridors degrade the natural environment. Almost 30% of all installations were in croplands and pastures. It is possible that the mounting pressure from drought has made this shift to solar energy an easier decision for farmers.
After evaluating land-cover change from solar facilities, the researchers used the Carnegie Energy and Environmental Compatibility computer model to develop a compatibility index to identify areas of potential and direct conflict with respect to environmental resources California-wide. Compatible areas are areas that are already developed. For photovoltaic technology, they identified some 8,500 square miles of these compatible areas (11.2% of total PV installations) and 30,000 square miles of potential compatible areas (71.7% of PV installations).
Potentially compatible areas are the next best thing. They are not protected, they would not require heavy site preparation, such as grading steep slopes, and they are within 6 miles of transmission lines and roads. There are many locally unique considerations that come into this category, for instance view disruption for local residents. Incompatible areas are natural and protected areas. The scientists found that some 55.5% of CSP installations were in either compatible or potentially compatible areas.