Solar farms—just like regular farms—cover large swaths of land, requiring between 3.5 to 16.5 acres per MW of generating capacity. The largest solar plant in the world, the 648 MW Kamuthi facility in Tamil Nadu, India, covers ten square kilometers. But it will be dwarfed by the 3,450 MW facility under construction on China’s Tibetan Plateau, which will span 298 square kilometers when completed. Building these large plants requires fundamentally changing how the land they sit on is used, which—without careful planning—could have negative impacts on the environment and local communities that could potentially lead to conflict. The backlash could not only derail solar projects, but could also fuel resistance to future renewable energy development.

Competing Demands: Water, Energy, and Food

Solar energy is increasingly affordable- in fact the price of utility-scale generation has dropped by 86% since 2009. As costs fall, many countries plan to expand solar generation dramatically to meet international climate commitments; China alone added 52.8 GW of solar generation last year. But there are challenges with integrating solar generation into the grid, since it is dependent on sunlight and is thus an intermittent source. Photovoltaic (PV) panels stop producing when the sun stops shining, while concentrated solar power harnesses thermal energy from the sun’s rays, allowing generation to continue only briefly after sunset. These limitations could impede development or make other power sources more attractive. Some new solar facilities are built on agricultural land, eliminating livelihoods and reducing local food production. This land-use change can stir tensions in rural communities, as happened in Connecticut where farmers who leased land found themselves in competition with clean energy. And especially in poorer and marginalized communities, it could change food production for decades. One state-run solar company in India leases farmland for 28 years, paying farmers much more than they would have made from their harvests.

Often, the land most suitable for solar energy is in dry climates where water is extremely scarce. While solar photovoltaic facilities use little water, solar thermal plants use vast quantities of water for cooling and cleaning. In the North African desert, Morocco’s enormous $9 billion Noor solar thermal complex competes with local agriculture for water from the El Mansour Eddahbi dam, consuming about six million cubic feet of water each year.  As Tunisia and other countries throughout the arid Middle East consider building solar thermal plants, they must figure out where the water will come from.  

Equity, the Environment, and the Exploited

Although solar generation is emissions-free, the construction process can have detrimental effects on the environment. The process of producing raw materials and siting facilities disturbs local ecosystems. PV panels require some rare materials, like silver, whose extraction is energy intensive and polluting. In the “rare earths kingdom” of Ghanzou, China, the 190 million tons of waste from abandoned mines will take 70 years to address. And efforts to recycle inputs for both solar thermal and PV solar facilities are under-developed.

Solar farms can also reinforce inequality. Subsidies and carbon taxes have made cleaner energy cheaper. In Germany, a backlash against renewable energy has mounted in opposition to the high costs these measures impose on poorer consumers who remain dependent on utilities and the grid. Similarly, the poor and even communities where solar energy is produced may not receive the electricity. A massive solar plant proposed for Tunisia was branded “neocolonialist” because it would have delivered electricity straight to Europe through undersea cables.

In the Mojave Desert, the Colorado River Indian Tribes are protesting the development of utility-scale solar facilities, which they argue will disturb archaeological sites and harm biodiversity. The tribes claim that the project developers did not adequately consult with them, as required by federal law.

Other renewable energy projects, such as hydroelectric dams and wind farms, have faced similar opposition from local communities concerned about environmental impacts or land rights. Sometimes the resistance is successful; in the Mexican state of Oaxaca, the federal court blocked a large wind project due to inadequate consultation with indigenous Zapotecs. In other instances, the local communities lost their battles—and even their lives, as in northeast India in 2016, when anti-dam protestors were killed.

The Bright Side

If planned thoughtfully, solar projects can avoid land-use conflict. The built landscape offers major opportunities for siting small-scale solar, including on roofs and walls. New programs like RE-Powering America’s Land have converted abandoned industrial sites and defunct landfills into solar farms. Combining wind and solar generation into one facility can reduce the space and infrastructure required as well as help balance intermittency issues. And solar farms can even co-locate with real farms: Agricultural researchers have found that crops grow beneath solar panels—and the plant can provide cheap electricity to power farm operations.

Solar energy could help alleviate, rather than exacerbate, countries’ water problems. Solar PV, which is more common and less water-intensive than solar thermal, uses water only in manufacturing and periodic cleaning. For some developing countries facing water stress, solar PV’s efficiency is pivotal. A World Resources Institute report found that switching to solar PV and wind energy would significantly reduce India’s water-energy nexus challenges by reducing the need for thirsty fossil fuel plants.

Furthermore, solar facilities could power energy-intensive activities such as crop irrigation or water pumping, reducing their carbon footprint. Solar-powered drip irrigation can be more water-efficient and more cost-effective than traditional methods, as demonstrated by a pioneering project in Benin. Water pumps powered by solar panels, which are widespread in the Asia-Pacific region, make fresh water supply possible for rural developing communities not connected to the main grid. The power of the sun is being harnessed to power street lamps and trash compactors, and even to create drinking water from the air.

Some countries have recognized the importance of participatory planning and democratic management to ensure a sustainable, conflict-free solar strategy. Solar projects are booming in Kenya, where the constitution mandates that energy sector decisions are made at the county level. Two companies plan to invest $23 million in solar-storage micro-grids, using blockchain and micro-funding to further democratize and increase access to Kenya’s energy sector.  

For solar energy to be successful at the scale required by climate change mitigation, solar facilities must be harmonized with the ecosystem, agriculture, and human needs. If local communities are excluded, and knock-on effects are overlooked, the benefits of renewable energy could be outweighed by negative consequences. But if innovative strategies and inclusive approaches continue to gain momentum, the future of solar energy will be bright.