The potential land requirements and related land use change emissions of solar energy

Abstract

Although the transition to renewable energies will intensify the global competition for land, the potential impacts driven by solar energy remain unexplored. In this work, the potential solar land requirements and related land use change emissions are computed for the EU, India, Japan and South Korea. A novel method is developed within an integrated assessment model which links socioeconomic, energy, land and climate systems. At 25-80% penetration in the electricity mix of those regions by 2050, we find that solar energy may occupy 0.5-5% of total land. The resulting land cover changes, including indirect effects, will likely cause a net release of carbon ranging from 0 to 50 gCO₂/kWh, depending on the region, scale of expansion, solar technology efficiency and land management practices in solar parks. Hence, a coordinated planning and regulation of new solar energy infrastructures should be enforced to avoid a significant increase in their life cycle emissions through terrestrial carbon losses.

Figure 1

Geographical distribution of the share of total land occupied by solar energy within each region, by agro-ecological zone. See “Methods” section and Figure S1 of the SM for more information on the spatial resolution used in this study. Source: Authors´ own elaboration with the Arc GIS 10.5.1 Desktop (Esri) software.

Figure 2

Global land-cover changes by 2050 due to solar expansion, for a range of solar energy penetration levels and for an average efficiency of installed solar modules of 24% by 2050. The upper graphs shows total land cover changes by 2050 relative to 2015 within each region and the lower side shows the land cover changes in the rest of the world (leaking), indirectly driven by the penetration of solarland within the region. Positive land cover changes refer to increases and negative to land cover loss. See Section 3b in the SM for aggregated global land cover changes. Note that land cover changes do not correspond with land use changes: this figure compares total land cover in different scenarios of land-based solar energy penetration, but does not show which specific types of land convert to solarland (or any other type of land). Note that these land cover changes are based on simulated land use decisions driven by economic optimisation. See “Methods” section for more details.

Figure 3

Land use change emissions related to land occupation per kWh of solar energy from 2020 to 2050, for the three solarland management regimes applied (see “Methods” section for more details), and relative to other life cycle emissions of PV systems (depend on location of installation) and emissions from natural gas fired electricity (independent of location). Uncertainty bounds reflect solar module efficiency scenarios (reaching average efficiencies of 20, 24 and 28% for modules installed in 2050; see Section 2c in SM). ¹ Non-land life cycle emissions of PV are based on a range of PV technologies, including mono and multicrystalline silicon (higher range), thin-film CdTe (lower range), CIS and a-Si systems as calculated in Liu & van den Bergh (2020), and based on an average global carbon intensity of electricity (0.48 kg CO₂/kWh). The range is calculated by dividing the regionally weighted solar electricity output per m² as used in this study, by CO₂ emissions per m² panel surface.