Energy generation can have intensive or extensive land use requirements, causing habitat and biodiversity loss in sensitive and diverse ecosystems globally or competing with other land use such as agriculture.
As a direct consequence of the Paris Climate Agreement, which requires global decarbonization, renewable energy sources will continue to expand, in particular solar and wind. The increasing land use for renewable energy generation systems and related infrastructure will become more relevant in the future. The extent to which the overall land use balance will be more favourable than for non-renewable sources depends on the mix of renewables, their siting and centralized or decentralized mode of deployment (UNEP, 2016). Innovative deployment of renewables can reduce land use pressures, as well as avoid landscape disturbances caused by fossil fuels and nuclear energy (Lovins, 2011).
While the use of fossil fuels is limited by the size of the resource (including future cost and the carbon dioxide (CO2 ) budget), renewable energy and in particular solar energy, is mostly restricted by land use allocation and by the availability or solar irradiation or adequate windspeeds.
Land or sea occupancy is one of the most visible impacts for any energy development. The relatively large land requirement for solar energy highlights the importance of good mitigation practices to help facilitate the transition into a renewable energy future. Fortunately, the abundance of solar energy means that, unlike other energy sources, there is often flexibility in project siting, allowing the integration of solar energy systems with buildings and infrastructure assets or the co-location of solar energy systems with agricultural practices or the use of wastelands.
Tamil Nadu has set a target of adding a 20 GW of solar energy by 2030. If this target is to be primarily met by ground-mounted solar plants a 405 km2 land area will be required. Considering the projected annual electrical energy demand of 4,89,395 MU by 2050 (Auroville Consulting 2022) the need to decarbonize the state’s power sector and the fact that solar is among the most cost -efficient energy sources today, the potential land-impact of solar is substantial. Meeting 50% of the projected electricity demand for 2050 would require 133 GW of solar capacity, and 2,691 km2 of land resources, which equals the total geographical area of Chengalpattu District or 2.07% of the state’s geographical area.
There are competing and often conflicting demands for land for economic, ecological, and social needs in the development sector. It will be critical to limit the conversion of agricultural lands for solar energy development.
In this context land-neutral and low land-impact solar energy developments need to be prioritized. The concept of land-neutral solar project refers to the integration of solar project into existing building and infrastructure assets such as building- integrated or infrastructure-integrated solar energy systems. Floating solar energy on water bodies, can be considered as a land-neutral solar energy option as well. Low land-impact solar energy also includes agrovoltaic projects that facilitate the co-location of agriculture and solar energy generation or wind-solar hybrids. Developing energy on lands degraded by human activities is another option to reduce cumulative impacts and minimize land use conflicts. Integrated spatial land use planning can facilitate sustainable development that finds the right balance between socio-economic aspirations and environmental considerations. Policy guidelines that address the solar energy – land nexus and provide an effective hierarchical spatial planning framework for solar energy, could ensure the judicious use of land while meeting the state’s solar energy needs.