When it comes to generating electricity, it’s a given that renewable energy sources produce lower amounts of global warming emissions than fossil fuels This, of course, has made renewables a popular alternative. But are some harmful aspects of renewable energy production being overlooked?
The Union of Concerned Scientists notes that renewable energy sources (solar energy, wind energy, geothermal energy and hydroelectric power) do have environmental impacts, some of which can be particularly damaging. Various environmental damages from renewable sources can be traced to their specific source, as types of environmental damages correspond to specific renewable sources.
Solar energy
The U.S. Energy Information Administration claims construction of large solar power plants can impact and displace native plant and animal habitats. Some solar power plant water intakes affect nearby ecosystems (namely, aquatic ecosystems). In addition to displacing animal habitats, the light from solar plant power towers can kill birds and insects that fly nearby.
In 2015, Hawaii’s SolarCity signed a 20-year contract to place a 52-megawatt hour battery system beside the Kapai power plant in Kaua’i. The battery system allows for energy to be stored to use at night and acts as the first fully dispatchable solar energy storage project in the United States.
Bob Rudd, SolarCity’s director of energy storage project development, told the audience at the international IDTechEx Energy Harvesting and Storage conference about SolarCity’s new project. “We’re really excited about [this project] because it’s effectively, as far as we know, the first-utility-scale solar-plus-storage project done on a purely commercial basis that is affecting the shift of the cast portion of PV production to the nighttime peak,” Rudd said. “So what we’ve done here is taken a 13-megawatt-AC PV system, and coupled it with a 13-megawatt/52-megawatt-hour battery bank, and effectively shifted … at least the vast majority of that midday solar production to the evening hours when they have their true peak even on the island.”
Wind energy
In regards to wind energy, the EIA notes that wind turbines, the source of wind energy, have caused thousands of bat and bird deaths, and they have occasionally caught on fire or have leaked oil.
Although the U.S. government and the American Wind Energy Association do not have a permanent solution to prevent bat and bird deaths by wind turbines, they are making large efforts to reduce bat and bird mortality. According to John Anderson, senior director of the American Wind Energy Association, the AWEA in 2015 began programing turbines to pivot parallel to the wind on windless autumn nights (during bats’ fall migration period), which keeps the turbines’ blades still.
Dr. Michael Hutchins, director of the American Bird Conservancy’s Bird-Smart Wind Energy Campaign, argues that the location of wind farms is a critical issue. Hutchins told National Geographic in an interview that “[wind farms] should be kept away from major bird and bat migratory routes, hilltops, or other sensitive habitats where birds and bats gather in large numbers to breed nest, or roost.”
The Bats and Wind Energy Cooperative was founded in 2003 in efforts to reduce bat deaths. BWEC has conducted various experiments to determine how wind energy can become more bat-friendly, and it continues to research methods to minimize wind energy’s impact on the environment.
Geothermal energy
Geothermal energy is energy sourced from the Earth’s heat. Hydrothermal plants create geothermal energy by drilling into geologic hot spots on the planet’s surfaces. Though geothermal energy is more sustainable and environmentally friendly than coal-generated energy, it still impacts the quality of water, air emissions and contributes to global warming. In fact, according to the Union of Concerned Scientists, approximately 10 percent of air emissions from open-loop geothermal systems are carbon dioxide – which is still significantly less than coal-generated energy’s carbon dioxide emissions.
Since geothermal power plants typically require wells, the Office of Energy Efficiency and Renewable Energy proposed that using slant-drilling technologies minimalize well impact on land and allow multiple wells in one location.
Hydroelectric energy
Hydroelectric power is produced through dams and river plants. All dams that create reservoirs can impact water temperatures, obstruct and injure fish migration, influence river flow characteristics and affect the overall ecology of a body of water. Additionally, greenhouse gases are able to form in reservoirs and are consequently emitted into the atmosphere.
Global warming emissions are much higher in tropical areas with hydroelectric plants – once the area floods vegetation decomposes and releases greenhouse gases. Though the amount of emissions varies depending on the area and its characteristics, the Union of Concerned Scientists notes that an estimated 0.5 pounds of carbon dioxide equivalent per kilowatt-hour are released in a life-cycle emission (still considerably less than coal-generated electricity estimated at 1.4 to 3.6 pounds of carbon dioxide equivalent per kilowatt-hour).
Fish and aquatic organisms can be injured or killed by hydropower turbine blades. In hopes to find a solution for reducing fish deaths in turbines, the U.S. Department of Energy has sponsored research to lower fish deaths from 5-10 percent to less than 2 percent. Fish ladders and in-take screens act as solutions to prevent the obstruction of fish migration, and assist fish trying to move over or around damns.
Make no mistake: Renewable energy sources improve public health, decrease global warming emissions and provide jobs that benefit the economy. They are indisputably more efficient and environmentally friendly than fossil fuels, but renewable energy sources still impact the environment. As more people recognize these environmental impacts, more solutions will be presented to strengthen these renewable energy sources and lessen those negative impacts.
Elizabeth Chen is a freelance journalist and senior at the University of North Carolina at Chapel Hill. She is currently an intern for INDY Week and The Reading List editorial. Connect with her on Twitter.