Is Clean Energy Really Clean?

The use of clean energy sources like solar, wind, and hydropower has grown rapidly in recent years as countries and companies work to reduce their carbon footprints and shift to more sustainable practices. While renewable energy is widely seen as better for the environment than burning fossil fuels, it does still have some negative impacts that are important to consider. This article examines the main environmental benefits of clean energy as well as the potential downsides, to provide a balanced look at its overall impacts.

The thesis is that clean energy has clear environmental advantages over fossil fuels when it comes to air pollution, greenhouse gas emissions, and water use. However, all energy sources have effects on habitats and require materials that must be sourced and disposed of responsibly. There are also reliability challenges to integrating high levels of renewables onto the grid. Overall, the message is that clean energy has major benefits but its drawbacks should not be ignored as we transition our energy systems.

Table of Contents

Types of Clean Energy

There are several main types of clean and renewable energy sources that are commonly used today. These include:

Solar – Solar panels and solar thermal systems harness energy from the sun to generate electricity or heat, usually converting sunlight into electricity using photovoltaics or concentrating solar power (National Grid).
Wind – Wind turbines use airflow to spin large blades connected to a generator that converts the rotation into electricity (NRDC).

Hydro – Hydropower systems use flowing water from rivers or streams to spin turbines and produce electricity (Department of Energy).
Geothermal – Geothermal energy harnesses heat from under the earth’s surface to provide heating/cooling or generate electricity.
Biomass – Bioenergy and biofuels utilize organic matter like plants, organic waste, and other biological materials as an energy source.

These clean energy sources offer renewable alternatives to burning fossil fuels like coal, natural gas, and oil. They do not require extracting and burning finite resources that emit greenhouse gases.

Reduced Air Pollution

Switching to clean energy sources like wind and solar power can significantly reduce air pollution compared to fossil fuels like coal and gas. Burning fossil fuels releases pollutants like nitrogen oxides, sulfur dioxide, particulate matter, and mercury into the atmosphere. These pollutants contribute to smog, acid rain, and poor air quality which can lead to respiratory illnesses. According to a recent study, replacing fossil fuel electricity sources with renewable energy could reduce premature deaths in the U.S. from air pollution by over 60,000 per year. Renewable energy results in major reductions of fine particulate matter, which is among the most dangerous forms of air pollution.

Lower Greenhouse Gas Emissions

Clean energy from renewable sources like wind, solar, hydro, and geothermal emit significantly fewer greenhouse gases than fossil fuels like coal, oil, and natural gas. According to the UN, renewable energy sources emit little to no greenhouse gases and are a key part of “powering a safer future” (https://www.un.org/en/climatechange/raising-ambition/renewable-energy). The International Renewable Energy Agency (IRENA) states that electricity from renewables can “immediately and significantly reduce global carbon emissions” (https://www.irena.org/Digital-content/Digital-Story/2019/Apr/How-To-Transform-Energy-System-And-Reduce-Carbon-Emissions). The EPA also notes that renewable energy helps reduce greenhouse gas emissions associated with energy production (https://www.epa.gov/greeningepa/carbon-pollution-free-electricity-epa). Transitioning to renewable sources is a key step in mitigating climate change and meeting emissions targets.

Less Water Use

Many clean energy sources use significantly less water than fossil fuels. According to the International Energy Agency, solar PV and wind energy use over 90% less water than coal power plants. Hydropower is unique in its reliance on water, but still uses less water than fossil fuel plants. The US Department of Energy states hydropower turbines only consume 1-10 gallons per megawatt hour, whereas coal plants may consume 500-600 gallons per megawatt hour.

Widespread adoption of wind and solar energy could greatly reduce water usage in the energy sector. According to McKinsey & Company, a 5% increase in renewable energy use in water-stressed countries could reduce water consumption by 6% for power generation. As climate change increases droughts, utilizing low-water energy sources will be crucial.

Habitat Disturbance

While renewable energy is often promoted as being eco-friendly, some clean energy projects can disrupt wildlife habitats. Large-scale wind and solar facilities take up significant land areas, leading to habitat loss and fragmentation. For example, one study found that utility-scale solar facilities occupied a median land area of 10 acres per megawatt of power generated (1).

The construction of renewable energy plants and associated infrastructure like access roads can destroy or degrade natural habitats. Species may abandon areas that have been altered. The displacement of wildlife can also increase competition in remaining habitat areas (2).

Marine habitats face disruption from offshore wind farms. The introduction of turbines and underwater structures can change seabed conditions and hydrodynamics. This may negatively impact marine organisms. For instance, important fishing grounds could be lost (3).

While renewable energy decreases emissions, projects must be sited and operated responsibly to minimize biodiversity impacts. Promoting distributed renewable energy generation could help reduce land requirements. Proper siting, project review processes and habitat restoration measures are also needed.

Sources:

(1) https://www.endangered.org/how-renewable-energy-impacts-biodiversity/

(2) https://energy5.com/the-impacts-of-renewable-energy-on-wildlife-and-biodiversity

(3) https://tethys.pnnl.gov/stressor/habitat-change

Materials Sourcing

Clean energy technologies like solar panels, wind turbines, and electric vehicle batteries require materials like rare earth metals, lithium, and cobalt to function. Mining these materials has concerning environmental impacts. For example, lithium mining uses large amounts of water in arid regions and can pollute underground aquifers (https://climate.mit.edu/ask-mit/how-does-environmental-impact-mining-clean-energy-metals-compare-mining-coal-oil-and-gas). Cobalt mining in the Congo often relies on child labor and unsafe working conditions. While fossil fuel extraction also has high environmental costs, the material demands of clean tech at scale could exacerbate habitat loss, water scarcity, and human rights abuses in mining areas. More recycling and ethical sourcing of these materials is needed to make their use truly sustainable.

Waste Disposal

While solar energy and batteries help reduce air and water pollution, they create new waste disposal challenges. Solar panels typically last around 20-30 years before needing replacement. Lithium-ion batteries in energy storage systems may need replacement after 10-15 years. Recycling these technologies is important to limit environmental impacts. According to Altestore, solar panels are 80-90% recyclable, but cells are incased in ethylene vinyl acetate making recycling tricky.^[1] Proper solar panel recycling recovers aluminum, glass, and semiconductor materials for reuse. Battery recycling recovers lithium, cobalt and nickel. However, not all areas have accessible solar panel and battery recycling options, so waste may end up in landfills. Sinovoltaics notes that some solar battery chemicals are toxic if mishandled.^[2] While recycling systems are developing, policies and infrastructure need improvement to handle growing solar technology waste streams.

[1] https://www.altestore.com/blog/2021/12/recycling-solar-panels-batteries-solar-equipment/

[2] https://sinovoltaics.com/learning-center/storage/solar-battery-disposal-solar-battery-recycling/

Reliability Challenges

While renewable energy sources like solar and wind are clean and emission-free, they can present grid reliability challenges compared to consistent power sources like fossil fuels. Many types of clean energy rely on favorable weather conditions to generate electricity. Solar power needs sunny skies and wind turbines require adequate wind. According to a study by the National Renewable Energy Laboratory, an electricity grid that relies heavily on wind and solar can have stability issues without proper planning and infrastructure upgrades (Clean and Reliable Power).

For example, California has aggressively expanded its use of renewables but has faced occasional rolling blackouts during heat waves when solar production drops in the evening. Upgrading transmission lines, using grid-scale storage, and having backup power supplies can help compensate when renewable resources are unavailable. While transitioning to clean energy is crucial for reducing emissions, it requires thoughtful planning and investment to ensure grid resilience and reliability (It’s time to rethink grid reliability). With the right strategies, clean energy can provide affordable and dependable electricity while also fighting climate change.

Conclusion

Clean energy sources like solar and wind power have major benefits over fossil fuels. They produce much less air pollution during operation and generate minimal greenhouse gas emissions. The fuel for renewable energy is generally free and unlimited, unlike coal or natural gas. Clean energy can help conserve water resources since thermal power plants require vast amounts for cooling. There are also challenges with implementing renewable energy on a large scale. The power output can fluctuate based on weather conditions. More transmission infrastructure is needed to distribute electricity from utility-scale solar or wind farms. While renewable energy facilities require less land than coal, they still disturb wildlife habitats during construction. Manufacturing solar panels and wind turbines consumes energy and resources. Decommissioning clean energy projects produces some waste as well. Overall, renewable energy has significant advantages for human health and the environment compared to fossil fuels. But the transition to clean energy is complex with pros and cons to consider.