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394 A COMPrEHEnSIvE GUIDE TO SOlAr EnErGy SySTEMS

California, would be affected by carbon-intensive and renewable energy development [6].
Ground-mounted solar energy requires relatively large expanses of land to support power
plant infrastructure, mirrors and towers (e.g., CSP), and panels (e.g., Pv), and therefore,
such installations are often sited far from urban population centers where most electricity
is consumed. This may necessitate additional transmission infrastructure (i.e., power line
corridors, roads, and substations) to transport electricity, expanding impacts beyond the
immediate footprint of facilities themselves. Hernandez and colleagues [7] found that Pv
and CSP ground-mounted USSE installations in California have a land-use efficiency of
−2
35.1 and 33.9 Wm , respectively, based on the nominal (i.e., nameplate) capacity. land
use efficiency can vary significantly from these averages. For example, Zichella and Hladik
[8] reported that a currently operational, 354 MW USSE facility in the California desert,
−2
United States, occupies over 645 ha, equal to 54.9 Wm and is a more efficient installation
based on nameplate capacity. In California, it was also found that installations on public
land required significantly more land per installed MW of capacity than those sited on
−2
private land (10 more Wm ), demonstrating flexibility in USSE design perhaps driven by
differences in the price of land [7]. This agrees with land estimates comparing Pv with coal
life-cycles by Fthenakis and Kim who showed that coal with surface mining in the U.S.
uses more land than Pv installed in the Southwest [63]. Also, they found that integrated
Pv and CSP technologies incorporated into the built environment had the lowest land-
use intensity across all sources of electricity, underscoring the potential to avoid negative
impacts on the biosphere through appropriate siting decisions.

20.2.2 Land-Use and Land-Cover Change

In light of the land area requirements of displacive solar energy installations, land-use and
land-cover change is a significant conservation concern. relative to other energy produc-
tion systems, renewable sources of energy may occupy a relatively small percentage of new
land area being affected by energy development in the United States under the assumption
that Pv and CSP would comprise only 0.5% and 0.04% of United States energy production
from 2012 to 2040 [6]. However, if larger percentages of displacive installations are realized, it
would scale accordingly. Additionally, displacive facilities may be disproportionately sited in
areas where high biological endemism (species with very limited distributions that are often
highly adapted to their environments), fragile habitats, and high solar resources co-occur,
such as the Mojave Desert in the southwestern United States. Indeed, deserts and xeric shru-
bland habitat types in the United States are expected to experience the greatest land-cover
change impacts due to Pv and CSP siting by 2030 [9]. Hernandez and colleagues [7] found
that the plurality of USSE developments in California are sited in shrublands and scrublands,
the land cover type with the highest inherent biodiversity of those included in the study,
2
necessitating 375 km of additional land. Additional conflicts may arise when solar facilities
2
are sited in areas where land has agricultural value; for example, 118 km of land categorized
as cultivated cropland has been converted to or is earmarked for USSE development in Cali-
fornia [7]. lastly, USSE may also be disproportionately sited in areas with biophysical capac-
ity to support ecosystem services, including carbon sequestration and storage. De Marco