Environmental impact




The ability of biomass and biofuels to contribute to a reduction in CO
2 emissions is limited because both biomass and biofuels emit large amounts of air pollution when burned and in some cases compete with food supply. Furthermore, biomass and biofuels consume large amounts of water. Other renewable sources such as wind power, photovoltaics, and hydroelectricity have the advantage of being able to conserve water, lower pollution and reduce CO
2 emissions. The installations used to produce wind, solar and hydro power are an increasing threat to key conservation areas, with facilities built in areas set aside for nature conservation and other environmentally sensitive areas. They are often much larger than fossil fuel power plants, needing areas of land up to 10 times greater than coal or gas to produce equivalent energy amounts. More than 2000 renewable energy facilities are built, and more are under construction, in areas of environmental importance and threaten the habitats of plant and animal species across the globe. The authors' team emphazised that their work should not be interpreted as anti-renewables because renewable energy is crucial for reducing carbon emissions. The key is ensuring that renewable energy facilities are built in places where they do not damage biodiversity.

Renewable energy devices depend on non-renewable resources such as mined metals and use vast amounts of land due to their small surface power density. Manufacturing of photovoltaic panels, wind turbines and batteries requires significant amounts of rare-earth elements and increases mining operations, which have significant social and environmental impact. Due to co-occurrence of rare-earth and radioactive elements (thorium, uranium and radium), rare-earth mining results in production of low-level radioactive waste.

Solar panels change the albedo of the surface what increases their contribution to global warming.

Mining for materials needed for renewable energy production is expected to increase threats to biodiversity. In September 2020 scientists published a world map of areas that contain renewable energy materials as well as estimations of their overlaps with "Key Biodiversity Areas", "Remaining Wilderness" and "Protected Areas". The authors assessed that careful strategic planning is needed.

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