Advanced photovoltaic technology can reduce land requirements and climate impact on energy generation

Solar photovoltaic (PV) technology is a rapidly growing source of clean energy, currently the third largest renewable energy source globally. Its deployment is accelerating, with significant growth rates observed in recent years. However, a crucial factor influencing future PV potential is the land area required to meet global energy demands, especially considering the potential negative impacts of climate change on PV energy generation. Climate change is projected to alter solar radiation and increase temperatures, potentially reducing global PV potential. While current PV installations will likely remain operational for several decades, the rate at which more efficient technologies are developed and deployed to offset climate change impacts remains uncertain. This study investigates the land area requirements for PV deployment to meet future energy demands under various scenarios, considering both conventional and advanced PV technologies, and accounting for climate change impacts. Understanding these land requirements is critical given the competition for land from other uses. The research seeks to answer three key questions: 1. How much land would be needed for PV to meet future energy demands under different PV technologies? 2. How do these land areas change when climate change impacts are considered? 3. How do PV potential and land requirements vary when combined with other land uses? The study's findings are crucial for informing policy decisions and planning for future sustainable energy generation.

Previous research on climate change impacts on PV potential using general circulation models (GCMs) has shown varying effects on different PV systems, with some studies indicating a decline in global PV potential for large-scale PV and an increase in rooftop PV potential. Localized changes in PV potential under climate change scenarios have been projected to range from -19% to +16%. Studies using regional climate models (RCMs) have projected larger PV potential declines, up to 20% in South Asia and Latin America and 34% in Sweden. However, these studies have not consistently explored the counteracting effects of technological improvements across different regions, technologies, or climate change scenarios. Previous analyses have highlighted the limitations of large-scale PV deployment due to competition with other land uses. However, the potential for multifunctional land use, such as agri-voltaic systems, has been recognized, offering a potential solution for mitigating land-use conflicts. Agri-voltaic systems, which combine solar panel installations with agricultural activities, are especially well-suited for pastures, allowing for simultaneous electricity and food production. Other potential areas for multifunctional PV deployment include highways, car parks, irrigation canals, and urban rooftops. A few studies have analyzed climate change impacts on global PV potential for specific scenarios, but without fully integrating the combined effects of climate change and technological advancements on global land requirements. This study aims to address this gap.

This study used climate change scenarios from four Representative Concentration Pathways (RCPs; RCP2.6, RCP4.5, RCP6.0, and RCP8.5) derived from four General Circulation Models (GCMs). These were combined with projections of future global energy demands from Shared Socioeconomic Pathways (SSPs; SSP1, SSP2, SSP3, SSP4, and SSP5). Six different PV technologies were considered, with details provided in the Supplementary Table 1. The analysis assessed the land area required to meet global energy demand under different SSP scenarios and more efficient PV technologies. Sensitivity analyses were conducted to explore the impact of climatic variables (solar radiation and temperature), technology, and land-use competition. The study determined the additional land required when climate change is factored in under different RCPs and how technology could offset negative climate impacts. Alternative land uses for PV deployment were also explored, including deserts, highways, urban areas, and grasslands. Data were obtained from various sources, including the Coupled Model Intercomparison Project Phase 5 (CMIP5), the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP2b) for bias-adjusted climate data, the IIASA database for SSP data, and other publicly available sources. The study used global gridded estimates of PV potential and projected energy demands to calculate the land area required for PV deployment under various scenarios. The analysis considered factors such as PV module efficiency, ground coverage ratio (GCR), and energy losses. A univariate sensitivity analysis was performed to evaluate the influence of individual climate variables (solar radiation and temperature) on PV potential under different climate change projections. The impact of climate change was assessed both globally and regionally across seven World Bank regions. The amount of solar PV energy generated under different PV settings (land-use fractions and technologies) was compared with projected energy demands, both globally and regionally.

The study found that the land area required for PV to meet global energy demand by 2085 strongly depends on the technology used. Conventional silicon (Si) PV would require 0.5–1.2% of global land area, increasing to 0.7–1.5% when considering climate change impacts. However, more efficient technologies such as perovskites and III-V multijunctions could reduce this requirement to 0.3–1.0%. Regional variations in land requirements were substantial, with East Asia and the Pacific, and the Middle East and North Africa requiring the most land. Climate change impacts, largely attributed to temperature increases reducing PV panel efficiency, resulted in a decline in global PV potential (-3.7% to -4.5% in 2050, and -3.4% to -5.0% in 2085). Regional impacts varied significantly, with potential decreases of up to -3% in Latin America and the Caribbean and -8% in South Asia. Despite these negative impacts, technological advancements can more than compensate for climate-related reductions in PV potential. The study further examined the combined effects of climate change and technology on land area requirements. Under high emission scenarios (SSP5-RCP8.5), meeting energy demand with conventional Si PV would require an increase of 1.5% (or 3% with GCR considered) of global land area compared to scenarios without climate change. However, using III-V multijunctions PV technology could reduce this to 0.7% (or 1.4% with GCR). The study also assessed the potential for PV deployment in various land-use sectors. Using the Sahara Desert for PV could potentially generate 5–11 times the global energy demand. Using highways for PV could generate 1.2 times more energy than demanded in 2085 under SSP1-RCP2.6. Urban areas could potentially generate 1.4 to 4.2 times the energy demanded in 2085. Utilizing grasslands for agri-voltaic systems could generate 0.3-1.3 times global energy demand. The study considered the implications of using different land-use sectors for PV deployment, such as the positive effects on biodiversity and the potential negative impacts on other ecosystem services or biodiversity.

The study's findings highlight the significant impact of both technological advancements and climate change on the future of PV energy generation. While climate change is projected to reduce PV potential, especially in certain regions, the deployment of more efficient PV technologies can effectively mitigate these negative impacts. The results demonstrate the potential for substantial reductions in land requirements through technological innovation. The assessment of alternative land-use strategies, such as agri-voltaics and the utilization of underutilized lands, showcases the potential for synergistic benefits, combining energy production with other land uses. The study emphasizes the regional disparities in both climate change impacts and PV potential. This underscores the importance of context-specific planning and technology selection for effective PV deployment. The study's findings support the argument for accelerating the development and adoption of advanced PV technologies to ensure a sustainable energy future. However, the successful implementation of large-scale PV deployment requires careful consideration of several factors, including energy storage, grid stability, and the potential environmental impacts of alternative land-use strategies. The study's results offer valuable insights for policymakers and researchers involved in planning for future renewable energy systems.

Large-scale PV deployment is crucial for meeting global energy demands and reducing climate change impacts. However, careful planning is needed to account for both climate change effects and land-use competition. The study demonstrates that advanced PV technologies can significantly reduce land requirements and mitigate the negative effects of climate change. Multifunctional land-use strategies, such as agrivoltaics, show promise but require further research. The study highlights the regional variability of climate change impacts and the potential for PV to contribute significantly to economic development in regions with high PV potential. Future research should focus on optimizing PV deployment strategies by considering various factors, including energy storage solutions and the environmental impacts of different land-use scenarios.

The study acknowledges several limitations. The use of CMIP5 climate projections, while widely used, might not capture the full complexity of future climate scenarios. The modelling assumptions and the specific PV technologies considered could also influence the results. The study did not account for all potential land suitability factors, such as soil type or topography, which might affect PV deployment. Furthermore, the uncertainties associated with future energy demands and the adoption rates of new technologies are inherent limitations. The study's focus on direct climate impacts on PV efficiency might not capture all the indirect effects. The analysis might not completely capture the indirect impacts, such as changes in cloud cover or air pollution, which could affect PV potential. The potential for policy interventions to shape PV adoption was not explicitly modeled.