What Is the Carbon Footprint of Renewable Energy? A Life-Cycle Assessment

What Is the Carbon Footprint of Renewable Energy? A Life-Cycle Assessment

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Grace Smoot

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Renewable energy is the generation of energy from infinite sources that can reduce the effects of global warming by limiting global greenhouse gas emissions. But not all renewable energy is equal in this respect. So we had to ask: What is the carbon footprint of renewable energy?

Per kWh produced, renewable energy emits between 11 and 740 gCO2 on a life-cycle basis. Depending on the type (solar, wind, hydropower, geothermal, tidal, wave, biomass), it can combat climate change and have various environmental benefits, but may still produce significant greenhouse gas emissions.

Renewable energies make up an ever-growing amount of total energy consumption and play a vital role in combating climate change. Keep reading to learn about the overall carbon footprint of renewable energy, its carbon footprint throughout its life-cycle, and its environmental impact.  

Here’s How We Assessed the Carbon Footprint of Renewable Energy

The carbon footprint is one of the ways we measure the effects of human-induced global climate change. It primarily focuses on the GHG emissions associated with consumption, but also includes other emissions such as methane (CH4), nitrous oxide, and chlorofluorocarbons.

Carbon footprint: the amount of greenhouse gases and specifically carbon dioxide emitted by something (such as a person’s activities or a product’s manufacture and transport) during a given period”

Merriam Webster

Basically, it is the amount of carbon emitted by an activity or an organization. This includes GHG emissions from fuel that we burn directly (e.g., heating a home, driving a car) and GHG emissions from manufacturing the products that we use (e.g., power plants, factories, and landfills).

Renewable energy is an energy substitute for fossil fuels (e.g., coal, oil, natural gas) that can reduce the effects of global warming by limiting global greenhouse gas emissions (GHGs). It is infinite by definition because the resources naturally replace themselves over time. 

Renewable Energy: energy that is produced using the sun, wind, etc., or from crops, rather than using fuels such as oil or coal | types of energy that can be replaced naturally such as energy produced from wind or water”

Cambridge Dictionary

Renewable energy is mostly non-polluting, low-maintenance, and promotes the decentralization of energy supply. On the flip side, renewable energy can come with lower immediate quantities of energy compared to non-renewable energy sources (e.g., coal, oil, natural gas). 

The 5 most common types of renewable energy are: solar, wind, hydropower, geothermal, tidal, wave, and biomass energy. 

To understand the carbon footprint of all energy types, we must assess their life-cycle and each stage’s carbon footprint. This life-cycle assessment (LCA) is a method to evaluate the environmental impacts of products and materials. Over the years, companies have strategically used LCA to research and create more sustainable products. So, we had a look at the LCA for all of the renewable energy types! (No worries, we’ll link back to each throughout this article.)

This Is the Carbon Footprint of All 5 Types of Renewable Energy

When discussing the carbon footprint of certain energy types, we must take into account carbon emissions across the energy’s building, operating, and building back phases.

On a life-cycle basis, the carbon footprint of renewable energy ranges anywhere from 11 to 740 grams of CO2 equivalent per kWh (gCO2 equivalent per KWh) of electricity produced. 

Type of renewable energyCarbon footprint 
SolarConcentrated: 38 gCO2/KWhPV
Roof: 41 gCO2/KWhPV
Utility: 48 gCO2/KWh
WindOnshore: 11 gCO2/KWh
Offshore: 12 gCO2/KWh
Hydropower24 gCO2/KWh
Geothermal38 gCO2/KWh
Tidal22 gCO2/KWh
WaveRelatively low, but more research is needed
BiomassRegular: 230 gCO2/KWh
Co-firing: 740 gCO2/KWh

Have a look at the illustration below to compare the average life-cycle CO2 equivalent emissions from renewable energies to those of different types of energy.

Illustration of CO2 equivalent per energy source
World Nuclear Association: Average life-cycle CO2 equivalent emissions

Renewable energy accounted for 11% of total energy consumption in the United States in 2019. This was equal to the amount of coal consumption and was nearly three times greater than consumption in 2000. Experts predict renewable resource consumption will continue to increase through 2050 as more and more effort is put into reducing global greenhouse gas emissions. 

Illustration of global renewable energy consumption
Our World in Data: Modern renewable energy consumption

However, only a very few countries have renewables as their primary energy source, while the vast majority of countries still have a long way to go.

Illustration of global renewable energy shares
Our World in Data: Share of primary energy from renewable sources

The 6 countries with the most primary energy coming from renewable energy are: 

  1. Iceland
  2. Norway
  3. Brazil
  4. Sweden
  5. New Zealand
  6. Austria
Illustration of share of renewable energy sources
Our World in Data: Share of primary energy from renewable sources

Driven by decreasing costs and improved technology, renewable energy capacity grew 3.7 fold from 2000-2020, increasing from 754 gigawatts (GW) to 2,799 GW. Because renewable energy is becoming a greater part of our energy mix, it is important to understand what its carbon footprint is. And how its carbon emissions affect the global climate change process.

Solar Energy Emits Between 38 and 48 Grams of CO2/kWh on a Life-Cycle Basis

Solar energy is the conversion of sunlight into electrical energy either through the use of photovoltaic (PV) panels or solar radiation concentrating mirrors. The energy produced is then used to generate electricity or can be stored in batteries or thermal storage for use at a later time. 

Solar Energy: energy that uses the power of the sun to produce electricity”

Cambridge Dictionary

Solar energy has the fifth-lowest carbon footprint. On a life-cycle basis, concentrated solar emits 38, PV roof solar emits 41, and PV utility solar energy emits 48 grams of CO2 equivalent per kWh of electricity produced.

Illustration of global solar energy consumption
Our World in Data: Solar Power Generation

Harnessing the power of the sun falls into two main categories:

  1. Photovoltaic (PV) solar cells: photovoltaic cells in solar panels absorb energy from sunlight, creating an electrical charge. This charge moves in response to an internal electric field in the cell, causing electricity to flow. 
  1. Concentrating solar thermal plants (CSP): mirrors reflect and concentrate sunlight onto receivers that collect and convert solar energy into heat. This is utilized in very large power plants.

Here are the life-cycle stages of solar energy and each stage’s carbon footprint:

  • Building of solar energy: CO2 emissions from the construction of solar power plants and electricity delivery mechanism
  • Operating of solar energy: Little to no CO2 emissions or waste products
  • Building back of solar energy: CO2 emissions from decommissioning the solar farms and land restoration
Related: Check out the full article about solar energy here: What Is the Carbon Footprint of Solar Energy? A Life-Cycle Assessment

Enough sunlight strikes the surface of the earth in an hour and a half to account for the world’s energy consumption in a year. Because solar energy has such a large electricity generation potential, it is important to understand what its carbon footprint is. And how its carbon emissions affect the global climate change process.

Wind Energy Emits 11 to 12 Grams of CO2/kWh on a Life-Cycle Basis

Wind is a form of solar energy that is caused by the uneven heating of the earth’s surface, irregularities of the earth’s surface, and the earth’s rotation. To harness wind energy, the wind turns the turbine blades around a rotor, which spins a generator to create electricity. An average annual wind speed of 9 miles per hour (mph) or 4 meters per second (m/s) for small turbines and 13mph (5.8m/s) for utility-scale turbines is necessary to economically harness wind energy

Wind: a current of air moving approximately horizontally, especially one strong enough to be felt”

Cambridge Dictionary

Wind energy has the lowest carbon footprint of all energy types. On a life-cycle basis, onshore wind emits 11 and offshore wind emits 12 grams of CO2 equivalent per kWh of electricity produced.

Illustration of wind global wind power generation
Our World in Data: Wind power generation

There are two main types of wind energy:

  1. Onshore wind energy: Turbines are located on land. Construction, transportation, maintenance cost, and infrastructure needed to transmit electricity from onshore turbines to consumers is low. However, they may be less efficient because onshore wind speed and direction can be unpredictable. 
  1. Offshore wind energy: Turbines are located in the ocean or freshwater. Construction, transportation, maintenance cost, and infrastructure needed to transmit electricity from offshore turbines to consumers is high. Offshore turbines are considerably larger than onshore turbines and can cost up to 20% more. Because wind speed and direction are more constant, the potential for energy generation is much higher. Noise pollution, land use, and wildlife impact concerns are minimal compared to onshore turbines. 

Here are the life-cycle stages of wind energy and each stage’s carbon footprint:

  • Building of wind energy: CO2 emissions from the construction of wind power plants and electricity delivery mechanism
  • Operating of wind energy: Little to no CO2 emissions or waste products
  • Building back of wind energy: CO2 emissions from decommissioning the wind turbines and land restoration
Related: Check out the full article about wind energy here: What Is the Carbon Footprint of Wind Energy? A Life-Cycle Assessment

The global installed capacity of wind energy increased by a factor of 75 between 1997 and 2018, growing from 7.5 GW to over 564 GW. Because wind energy is one of the cheapest and fastest-growing renewable energy technologies with a low carbon emissions profile, it is important to understand what its carbon footprint is and how its carbon emissions affect the global climate change process.

Hydropower Emits 24 Grams of CO2/kWh on a Life-Cycle Basis

Hydropower contributes to the avoidance of GHG emissions from the burning of fossil fuels (e.g. coal) and is classified as a renewable energy source because the resource (water) naturally replaces itself over time. To harness energy from water, flowing water turns turbines and spins a generator to generate electricity. 

Hydropower: hydroelectric power (= the production of electricity by the force of fast-moving water)”

Cambridge Dictionary

Hydropower energy has the fourth-lowest carbon footprint of all energy types. Per kWh produced, hydropower emits 24 grams of carbon dioxide (CO2) on a life-cycle basis.

Illustration of global hydropower consumption
Our World in Data: Hydropower Generation, 2020

Hydropower can be divided into three main categories depending on how many megawatts (MW) of power are generated.

Category of HydropowerGenerating Capacity
Micro Hydropower100 kilowatts (kW) or less
Low-Impact Hydropower (Low Hydro)Between 100 kW and 10 MW
Large Hydropower (Large Hydro)30 MW or more

And those categories can be defined as one of three types of hydroelectric facility:

  • Run-of-river: A facility that channels flowing water from a river through a canal or penstock to turn a turbine which spins a generator to produce electricity.
  • Storage: A large system that stores water in a reservoir via the use of a dam. Water is released from the reservoir to turn a turbine which spins a generator to produce electricity.
  • Pumped storage: A system that harnesses water that is cycled between upper and lower reservoirs by pumps. Water is released from the upper reservoir into the lower reservoir to turn a turbine which spins a generator to produce electricity.
  • Offshore: A system that uses tides or waves to generate electricity from seawater. This is the least established form of hydropower.

Here are the life-cycle stages of hydropower and each stage’s carbon footprint:

  • Building of hydropower: Construction and transportation of materials, emissions from reservoirs
  • Operating of hydropower: Little to no CO2 emissions or waste products
  • Building back of hydropower: None, if hydropower infrastructure can be maintained indefinitely
Related: Check out the full article about hydropower energy here: What Is the Carbon Footprint of Hydropower? A Life-Cycle Assessment

Hydropower makes up more than 60% of global renewable energy generation. Because the amount of GHG emissions from hydropower depends on the scale, it is important to understand what its carbon footprint is and how its carbon emissions affect the global climate change process.

Geothermal Energy Emits 38 Grams of CO2/kWh on a Life-Cycle Basis

The decay of radioactive materials in the rock and fluid of the earth’s core produces geothermal energy. Drilling down to hot water reservoirs up to a mile below the surface creates steam that rotates a turbine, which spins a generator to generate electricity. Geothermal is found along major tectonic plate boundaries where volcanoes are located. Because the Earth has an almost unlimited supply of heat generated by its core, and the water extracted from the reservoirs can be recycled via re-injection into the ground, it is a renewable energy source. 

Geothermal: involving or produced by the heat that is inside the earth”

Cambridge Dictionary

Geothermal energy has the fifth-lowest carbon footprint of all energy types. Per kWh produced, geothermal energy emits 38 grams of CO2 on a life-cycle basis.

Illustration of installed geothermal energy capacity
Our World in Data: Installed Geothermal Capacity

The three main types of geothermal power plants are: 

  1. Dry steam: Wells are drilled into underground reservoirs of steam. The steam is piped directly from the well to the power plant where it powers turbines and generators.
  1. Flash steam: The most common type of geothermal power plant. Very hot (360 degrees Fahrenheit, 182 degrees Celsius) water flows up through wells towards the surface under its own pressure. As it reaches the surface, some of the water boils into steam. The steam is then separated from the water and is then used to power turbines and generators at the power plant.
  1. Binary steam: Wells are drilled into underground reservoirs of hot water (225-360 degrees Fahrenheit, 107-182 degrees Celsius). The heat from the water is used to boil a working fluid, an organic compound with a low boiling point. This working fluid is vaporized into steam which is then used to power turbines and generators at the power plant. The water is then injected back into the ground where it is reheated and can be used again. 

Here are the life-cycle stages of geothermal energy and each stage’s carbon footprint:

  • Building of geothermal energy: CO2 emissions from drilling geothermal wells and construction of geothermal power plants
  • Operating of geothermal energy: CO2 emissions from the operation of geothermal power plants
  • Building back of geothermal energy: Little to no CO2 emissions or waste products
Related: Check out the full article about geothermal energy here: What Is the Carbon Footprint of Geothermal Energy? A Life-Cycle Assessment

The potential electricity generation for geothermal is 240 GW, with lower and upper limits of 50 GW and 1000-2000 GW, respectively. Because geothermal energy has a large electricity generation potential – and production has steadily increased in the last decade – it is important to understand what its carbon footprint is. And how its carbon emissions affect the global climate change process.

Tidal Energy Emits 22 Grams of CO2/kWh on a Life-Cycle Basis

The gravitational pull of the sun and moon coupled with the rotation of the earth creates tides in the ocean. To produce tidal energy, tidal turbines, barrages, and lagoons use the rise and fall of tides to spin a generator to produce electricity. A minimum tidal range of 10 feet is required to harness tidal energy economically.

Tidal Power: power that comes from the movement of the tide (= the rise and fall of the ocean that happens twice every day) and that can be used especially for producing electricity”

Cambridge Dictionary

Tidal energy has the third-lowest carbon footprint of all energy types. On a life-cycle basis, tidal energy emits 22 grams of CO2 equivalent per kWh of electricity produced.

Illustration of global marine energy capacity
Our World in Data: Installed Global Renewable Energy Capacity by Technology, Marine

There are three types of tidal energy technology:

  • Stream: turbines that spin a generator to create electricity are placed in tidal streams. 
  • Barrage: a barrage (dam) is placed across a river, bay, or estuary. The barrage gates open as the tide rises and close at high tide, creating a lagoon. The water is then released through the turbines which spin a generator to create electricity. 
  • Lagoon: a body of ocean water is partially enclosed by a man-made barrier. Lagoons function in the same manner as a barrage, but they generate continuous power and can also be constructed along a coastline. 

Here are the life-cycle stages of tidal energy and each stage’s carbon footprint:

  • Building of tidal energy: CO2 emissions from construction and transportation of materials
  • Operating of tidal energy: Little to no CO2 emissions or waste products
  • Building back of tidal energy: Theoretically, none as tidal infrastructure can be maintained indefinitely
Related: Check out the full article about tidal energy here: What Is the Carbon Footprint of Tidal and Wave Energy? A Life-Cycle Assessment

There are roughly 3,000 GW of energy stored in the world’s tides. Because the generating potential for tidal energy is so high, it is important to understand what its carbon footprint is. And how its carbon emissions affect the global climate change process.

Wave Energy Has One of the Lowest Carbon Footprints, but More Research Is Needed to Determine Exactly How Low It Is

Waves are formed when the wind blows over the surface of the water on oceans or lakes. 95% of the wave’s energy is stored between the surface of the water and the top 1/4th of the wave’s length. To produce wave energy, float/buoy, oscillating water columns, and tapered channel systems use the rise and fall of waves to produce electricity. 

Wave Power: electrical energy generated by harnessing the up-and-down motion of ocean waves”

Britannica

Wave energy has a low carbon footprint. Wave energy emits similarly low levels of CO2 compared to tidal energy, although more research is still needed.

Illustration of global marine energy capacity
Our World in Data: Installed Global Renewable Energy Capacity by Technology, Marine

There are three types of wave energy technology:

  1. Float or buoy: Anchored buoys use the rise and fall of waves to power hydraulic pumps. The “up” and “down” movement powers a generator to produce electricity, which is transported onshore via underwater power cables. 
  1. Oscillating water column: The “in” and “out” motion of waves at the shore enter columns, forcing air to turn turbines. As the waves enter the column, the air is compressed and heated, creating energy. The energy is then transported onshore via underwater power cables.  
  1. Tapered channel (Tapchan): Shore mounted structures channel and concentrate waves, pushing them into an elevated reservoir. The water is then released from the reservoir, flowing through penstocks and to turbines which power a generator to produce electricity. 

Here are the life-cycle stages of wave energy and each stage’s carbon footprint:

  • Building of wave energy: CO2 emissions from construction and transportation of materials
  • Operating of wave energy: Little to no CO2 emissions or waste products
  • Building back of wave energy: More research is needed
Related: Check out the full article about wave energy here: What Is the Carbon Footprint of Tidal and Wave Energy? A Life-Cycle Assessment

The market for wave energy is expected to reach $141 million by 2027. Because the generating potential for wave energy is so high, it is important to understand what its carbon footprint is. And how its carbon emissions affect the global climate change process.

Biomass Energy Has One of the Highest Carbon Footprints at 740 and 230 Grams of CO2/kWh on a Life-Cycle Basis

Biomass is renewable organic material that comes from plants and animals. It is incredibly versatile and can be used to produce fuel, energy, and everyday products that contain plastics.  Sources of biomass energy include wood and wood processing wastes, agricultural crops and waste materials, municipal solid waste, animal manure, and human sewage. To harvest biomass energy, these sources are burned or are converted to release the stored chemical energy from the sun. 

Biomass: natural materials from living or recently dead plants, trees and animals, used as fuel and in industrial production, especially in the generation of electricity”

Oxford Dictionary

On a life-cycle basis, regular biomass energy emits 230 grams of CO2 equivalent per kWh (gCO2 per KWh), the fourth-highest amount out of all of the fuel types, and the highest amount out of all of the renewable fuel types. However, co-firing biomass energy, where biomass is added as a partial substitute fuel in coal boilers, emits 740 gCO2 per KWh, the second-highest amount out of all fuel types and second only to coal. 

In 2018, 637 Terawatt hours (TWh) of electricity were produced globally from biomass. Solid biomass accounted for 66% (420 TWh), municipal and industrial waste 19% (121 TWh), and biogas 14% (89 TWh) of total biopower. Also in 2018, 160 billion liters (bl) of biofuels were produced globally from biomass. North and South America account for 75% and Europe 14% of global biofuel production. 

Illustration of global biofuel energy production
Our World in Data: Biofuel Energy Production

Here are the life-cycle stages of biomass energy and each stage’s carbon footprint:

  • Building of biomass: CO2 emissions from extracting and processing biomass, transportation of biomass on trucks or by rail, construction of biomass power plants 
  • Operating of biomass: CO2 emissions from biomass combustion, operation of equipment at biomass power plants
  • Building back of biomass: CO2 emissions from utilizing construction equipment to demolish the buildings and construct new buildings in the old power plant’s place
Related: Check out the full article about biomass energy here: What Is the Carbon Footprint of Biomass Energy? A Life-Cycle Assessment

Because biomass is still an important fuel source for the developing world and has become an important transportation fuel in the developed world, it is important to understand what its carbon footprint is and how its carbon emissions affect the global climate change process.

What Role Does Renewable Energy Play in Combating Climate Change

Fossil fuel combustion is the main contributor to atmospheric CO2 levels. Climate Change occurs when CO2 and other air pollutants absorb sunlight and solar radiation in the atmosphere, trapping the heat and acting as an insulator for the planet. Since the Industrial Revolution, Earth’s temperature has risen a little more than 1 degree Celsius (C), or 2 degrees Fahrenheit (F). The current global annual temperature rise is 0.18C, or 0.32F, for every 10 years. 

Using renewable energy (solar, wind, hydropower, tidal, wave, and geothermal), instead of fossil fuel energy helps mitigate the following negative effects of climate change:

  • Melting of sea ice: Since 1979, arctic sea ice has declined by 30%. Sea ice plays a major role in regulating the earth’s climate by reflecting sunlight into space and providing habitat for animal species. If all of the glaciers on Earth melted, sea levels would rise by approximately 70 feet, effectively flooding out every coastal city on the planet. 
  • Changing precipitation patterns: Extreme weather events (e.g., hurricanes, floods, droughts) are becoming more common and more intense. Storm-affected areas will experience increased precipitation and flooding whereas areas located further from storm tracks will experience decreased precipitation and droughts.
  • Ocean acidification: The ocean absorbs 30% of the CO2 released into the atmosphere, which decreases the pH (increases the acidity) of the ocean. In the past 200 years, the pH of oceans has decreased by 0.1 pH units, which translates to a 30% increase in acidity. Aquatic life unable to adjust to this rapid acidification will die off. A prime example of this is coral bleaching, where coral expel the algae (zooxanthellae) living in their tissues as a result of changes in temperature, light, or nutrients. 

Experts claim that to avoid a future plagued by rising sea levels, acidified oceans, loss of biodiversity, more frequent and severe weather events, and other environmental disasters brought on by the hotter temperatures, we must limit global warming to 1.5C by 2040

The more we reduce CO2 emissions, the more we slow the rate of temperature rise, sea-level rise, ice melting, and ocean acidification. When these rates are slowed, the earth’s biodiversity does not have to struggle to adapt to temperature and pH changes. People will not be displaced due to the flooding of coastal areas. And icebergs will continue to provide climate regulation. 

What Role Does Renewable Energy Play in Contributing to Climate Change

Biomass is often portrayed as a sustainable alternative to fossil fuels with CO2 reduction benefits. But every year, per kWh, biomass power plants emit 150% the CO2 of coal and between 300% – 400% the CO2 of natural gas, making them a major contributor to climate change. The carbon found in biomass reacts with oxygen in the air to produce CO2. This warms the earth by acting as a heating blanket, and a warmer earth comes with a host of negative side effects including temperature rise, sea-level rise, ice melting, and ocean acidification.

How Environmentally Friendly Is Renewable Energy

The overall environmental friendliness of renewable energy depends on which specific type of energy is being discussed.

Environmentally friendly: (of products) not harming the environment.”

Cambridge Dictionary

There are collective, as well as unique, benefits and drawbacks to renewable energy. 

What Are Environmental Benefits of Renewable Energy

All 7 renewable energies have the following two benefits:

  • Energy independence: Being able to produce our own electricity in the US without the aid of foreign countries is an important step to help us become more self-sufficient. Former President George W. Bush signed the Energy Independence and Security Act of 2007 to reduce U.S. dependence on oil, expand the production of renewable fuels (and confront global climate change). 
  • Employment opportunities: The renewable energy sector collectively employed 11.5 million people worldwide in 2019. Renewable energy jobs continue to increase as we start to realize just how beneficial renewable energy is for our environment. 

There are also specific benefits unique to each renewable energy type: 

  • Solar: Throughout its life cycle, concentrated solar energy produces 0.04%, PV roof solar energy produces 0.05%, and PV utility solar energy produces 0.06% of the CO2 emissions per unit of electricity than coal produces. 
  • Wind: Throughout its life cycle, wind energy produces 0.02% of the CO2 emissions per unit of electricity than coal produces. And after 3 to 6 months of operation, a wind turbine has effectively offset all emissions from its construction, which means it can operate virtually carbon-free for the rest of its lifetime.
  • Hydropower: Hydropower has the potential to reduce overall GHG emissions by 5.6 gigatons by 2050, which is equivalent to nearly 1.2 billion passenger vehicles driven in a year. This would also save around $209 billion in damages caused by climate change. 
  • Geothermal: Throughout its life cycle, geothermal energy produces 5% of the CO2 emissions per unit of electricity that coal produces. In the US alone, annual geothermal energy resources effectively offset the emission of 4.1 million metric tons (t) of CO2, 200,000 t of SO2, 80,000 t of nitrogen oxides, and 110,000 t of particulate matter when compared to conventional coal-fired plants.
  • Tidal and wave: Tidal energy produces 0.03% of the CO2 emissions per unit of electricity that coal produces, and wave energy also produces low levels of emissions. Tidal and wave energy could help reduce global CO2 emissions from fossil fuel electricity generation by around 500 million tons by the year 2050

Six of the seven renewable energies have climate change mitigation benefits because they have lower average life-cycle CO2 equivalent emission values compared to coal, the dirtiest of all the energies. Although biomass also has a lower value, the environmental drawbacks (listed in the next section below) outweigh the environmental benefits. 

What Are Environmental Drawbacks of Renewable Energy

Each renewable energy type comes with its own set of environmental drawbacks that should be taken into account when discussing its carbon footprints. 

  • Solar: The scale of land degradation and habitat loss depends on the technology, site topography, and intensity of the solar resource. Siting large-scale solar farms on abandoned land and small-scale farms on top of buildings or homes can minimize negative environmental impacts. Water is used for the construction of PV components, and CSPs require water for cooling. Hydrochloric acid, sulfuric acid, nitric acid, hydrogen fluoride, 1,1,1-trichloroethane, and acetone are all used to manufacture PV cells. If not handled and disposed of properly, these hazardous materials could present a serious risk to environmental and public health.
  • Geothermal: Geothermal reservoirs occur deep underground and are not detectable from the surface. Areas where geothermal does come to the surface are only found near tectonic plate boundaries. Also, high-pressure fluid injections close to neighboring fault lines have the potential to trigger earthquakes. 90% of all earthquakes occur in the Ring of Fire, an area that coincides with the highest concentration of geothermal resources. 
  • Tidal and wave: The main environmental concern with tidal and wave energy is the impact on aquatic wildlife. Construction and operation of marine energy technology may negatively impact estuarine ecosystems via underwater noise pollution, habitat changes, and wildlife collisions with turbines. Because tidal and wave energy is a relatively new technology, more research needs to be done to fully understand this environmental impact. 
  • Biomass: Existing biomass power plants emit more CO2 from their smokestacks than coal plants. Developed countries that burn organic matter for heat and cooking release particulate matter (PM), carbon monoxide (CO), hydrocarbons, oxygenated organics, free radicals, and chlorinated organics, all of which are health hazards. Chopping trees to produce wood pellets that are burned for electricity speeds up deforestation and reduces the number of trees that can capture our CO2 emissions (decreases carbon sequestration).

Overall, biomass is not as environmentally friendly as it appears to be at first glance. For biomass to be sustainable, the rate of harvest must not exceed the rate of forest growth. In reality, this rarely happens. Also, it could take anywhere from decades to well over a century before we start receiving the climate benefits provided by biomass, which is well outside the timeframe of averting our current climate crisis.

The easiest way to mitigate the environmental impact of biomass is to simply not rely on it in the first place. Biomass pollutes the air, leads to deforestation, and is not a sustainable energy source. Its combustion also adds to atmospheric CO2 levels and contributes to global warming.

Final Thoughts

Fossil fuels have been the world’s primary energy source for decades, but since 2000 there has been a push towards renewable energy types. Renewables have a lower carbon footprint across their building, operating, and building back phases. 

Renewable energies also combat climate change, create jobs, and promote energy independence, making them environmentally friendly energy sources. Any environmental concerns can all be mitigated by careful siting of power plants and proper disposal of any waste materials. Renewable energies benefit both our atmosphere and Earth’s biota.

Stay impactful,

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