We found large areas of the Mojave Desert that are potentially suitable for the development of solar facilities that are ecologically degraded with
FIGURE 3: Conservation values in potentially suitable lands for solar development below 5% slope angle. Urban areas, water bodies, and lands outside of private or BLM multiple use ownerships, and areas above 5% slope were removed. Conservation value colors are the same as Figure 2. Lands in darkest gray are classified as lower conservation value lands for which energy production estimates are provided in the results.
lower regional conservation value (Figure 3). The amount of lower conservation value land that meets the development suitability criteria ranges from nearly 200,000 ha (<1% land surface slope angle) to over 740,000 ha (<5% slope) (Table 1). The level of potential compatibility between development and conservation is much greater if land with higher slope can be utilized, with nearly four times more lower conservation value land at the 5% cutoff compared to the 1%.
TABLE 1: Area (ha) of land by land ownership, conservation value, and percentage slope angle.
Areas with lower than 7 kwh/m2/day direct normal irradiance (DNI) were excluded from the analysis, as were legally and administratively protected areas, urban areas, and perennial water bodies. BLM land includes only undesignated land eligible for potential siting. Higher percentage slope categories are inclusive of the lower. Conservation value categories from Randall et al. 2010.
Privately-owned parcels provide considerably more opportunity to develop on land with lower conservation value than do public lands (Figure 4, Table 1). The combined area of lower conservation value private land is 3.5 times (<1% slope) to 2.5 times (<5% slope) the area of those categories on suitable BLM land across the ecoregion. The higher degradation on private land is primarily due to agricultural land use and low density development in parts of the western Mojave in California and in the Arizona portion of the ecoregion. However, unlike BLM-managed lands, private lands are often parcelized and divided into many ownerships. In California, private lands that meet suitability criteria, are less than 5% slope and are in the lower conservation value categories, the average parcel size is
2.4 ha, with a median of 1 ha (Figure 5).
While most of the degraded areas potentially suitable for development are found on private land, BLM land also provides large areas of potential opportunity for development, with over 210,000 ha of lower conservation value land less than 5% slope across the ecoregion (Table 1, Figure 4). About 90% of those lands are available for solar use since approximately 10% (21,522 ha) are within designated off highway vehicle (OHV) open areas and thus likely to be off limits to and inappropriate for development.