Is Renewable Energy Clean Energy

Introduction

Renewable energy is energy generated from natural resources that are continuously replenished such as sunlight, wind, rain, tides, and geothermal heat (https://www.nationalgeographic.org/article/renewable-energy-explained/). The key aspect that makes renewable energy clean is that it comes from natural sources that are constantly renewed and do not emit greenhouse gases or toxic byproducts when generating power. In contrast, non-renewable energy like fossil fuels draw on finite resources that will eventually be depleted and produce carbon emissions and pollution when burned (https://www.prysmiangroup.com/en/insight/sustainability/renewable-energy-definition-and-types-of-clean-energy). This article will examine why renewable energy is considered clean energy in comparison to fossil fuels and other non-renewables.

Types of Renewable Energy

There are several major types of renewable energy sources that are used to generate electricity:

• Solar – Solar panels convert energy from the sun into electricity. Solar energy can be used at both large utility-scale solar farms and on rooftops of homes and businesses.
• Wind – Wind turbines harness the wind’s kinetic energy and convert it into mechanical power to spin a generator. Wind farms can consist of hundreds of individual wind turbines.
• Geothermal – Geothermal energy taps heat from under the earth’s surface to generate steam to spin turbines. This heat can come from hot water reservoirs near the surface or deeper rock at high temperatures.
• Hydropower – Flowing water spins large turbines to generate electricity at hydroelectric dams and power plants. Water’s kinetic energy is captured and turned into usable power.
• Biomass – Organic matter like plants, wood, and waste are used to generate electricity. As biomass decomposes, methane gas is captured and burned to spin generators.

According to the U.S. Energy Information Administration, the major renewable energy sources used for electricity generation are hydropower, wind, solar, geothermal and biomass (EIA).

Renewable Energy is Considered Clean Energy

Renewable energy sources like solar, wind, hydroelectric, geothermal and biomass are generally considered “clean” energy. This is because they produce little to no greenhouse gas emissions or air pollutants when generating electricity (Solstice.us, 2023 https://solstice.us/solstice-blog/renewable-energy-faq/). The environmental benefits of renewable energy include:

• Reduced air pollution and smog
• Lower carbon emissions that contribute less to climate change
• Less waste and pollution compared to fossil fuels
• Greater sustainability for future generations

Fossil fuels like coal, oil and natural gas emit high levels of carbon when burned to produce electricity. Renewable sources provide a much cleaner alternative that does not pollute the air or release toxic byproducts (Canyons.edu, 2023 https://www.canyons.edu/administration/committees/sceec/resources/information/renewable-energy.php). This makes renewable energy critical for reducing greenhouse gases and environmental damage.

Fossil Fuels are Not Clean

Fossil fuels like coal, oil and natural gas produce large amounts of greenhouse gases like carbon dioxide and methane when burned to generate energy. Greenhouse gases trap heat in the atmosphere, causing global warming and climate change. According to the Environmental and Energy Study Institute, fossil fuel combustion accounted for over 75% of global greenhouse gas emissions in 2010 [1]. Fossil fuels also emit air pollutants like sulfur dioxide, nitrogen oxides and particulate matter that are harmful to human health. The World Health Organization estimates that air pollution from fossil fuel combustion contributes to 7 million premature deaths per year globally [2].

Extracting and transporting fossil fuels can also damage the environment. Oil spills from offshore drilling and pipelines contaminate waterways and coastal areas. Fracking to extract natural gas consumes large amounts of water and has been linked to groundwater pollution and even earthquakes. Coal mining techniques like mountaintop removal devastate landscapes and habitats. The environmental and health damages from fossil fuels make them a far cry from clean energy sources.

Carbon Emissions Comparison

Renewable energy sources like wind, solar, and hydro produce significantly less carbon emissions over their lifetime compared to fossil fuels. According to one study, renewable energy sources typically emit around 50g or less of CO2 per kWh over their lifetime, whereas coal emits around 820g CO2 per kWh and natural gas emits around 490g per kWh (https://www.wri.org/insights/setting-record-straight-about-renewable-energy).

Fossil fuels are responsible for over 75% of global greenhouse gas emissions, making them the largest contributor to climate change by far (https://www.un.org/en/climatechange/raising-ambition/renewable-energy). While renewable energy comes predominantly from natural sources like sunlight, wind, and water movement, fossil fuels release ancient carbon stored beneath the earth’s surface into the atmosphere when burned.

Even as grids transition to 100% renewable electricity, work still needs to be done to eliminate carbon emissions completely. Some renewable sources like biomass and geothermal can still produce carbon emissions, though at much lower levels than fossil fuels (https://sustainability.stanford.edu/news/when-100-renewable-energy-doesnt-mean-zero-carbon). Overall, the evidence clearly shows renewable energy produces significantly fewer carbon emissions than fossil fuels.

Other Environmental Benefits

Renewable energy provides significant environmental benefits beyond reducing greenhouse gas emissions. By generating electricity from clean sources like wind, solar, and hydropower, renewable energy helps conserve wildlife habitats, ecosystems, and natural landscapes. For example, a large solar or wind farm requires much less land than coal mining or oil drilling (UN, 2023). Renewable energy projects can therefore help preserve biodiversity by avoiding deforestation and land disturbance.

Additionally, renewable energy saves tremendous amounts of water compared to fossil fuels. Thermal power plants require water for cooling, accounting for over 40% of water withdrawals in the U.S. (Nova, 2023). In contrast, most renewables like solar PV and wind turbines require little to no water for electricity generation. Hydropower generation itself consumes some water through evaporation, but overall renewable energy sources greatly reduce water consumption and aquatic impacts.

Over the long-term, transitioning to renewable energy is necessary for environmental sustainability. Fossil fuels are non-renewable and will eventually run out if not replaced by renewable alternatives. The renewable energy sources – solar, wind, geothermal, etc. – will not be depleted, supporting energy production indefinitely. Widespread renewable energy adoption leaves a much smaller environmental footprint, helping protect wildlife, natural resources, and ecosystems for current and future generations.

Limitations of Renewable Energy

While renewable energy has many benefits, it also comes with some limitations and challenges. One key limitation is intermittency – many renewable energy sources like solar and wind are variable and weather-dependent. They only generate energy when the sun is shining or the wind is blowing. This can make integrating large amounts of renewable energy difficult for energy grids that need steady and reliable power.

The intermittency also means that energy storage is crucial for renewable energy. Effective storage solutions like batteries and pumped hydro can store renewable energy for when it is needed most. However, at scale, energy storage also poses complex technical challenges and can be costly.[1]

Integrating renewable sources into existing transmission grids can also be challenging. Grid operators have to balance electricity supply and demand. With variable sources like solar and wind, advanced power electronics and control systems are needed to maintain reliability and stability on the grid.

Overcoming Limitations

While renewable energy has many benefits, it also comes with some limitations that need to be addressed. Two of the biggest limitations are intermittency and location constraints. The sun doesn’t always shine and the wind doesn’t always blow when energy is needed most. Additionally, the best solar and wind resources are often located far from major population centers. However, researchers and industry experts are working on innovative solutions to overcome these obstacles.

Improved forecasting methods and next-generation storage technologies like batteries, pumped hydro, and thermal storage are key to dealing with intermittency issues. Forecasting tools can better predict energy supply and demand mismatches, while storage provides a buffer between generation and usage. With sufficient storage capacity, excess renewable energy can be captured and discharged when needed. Storage also facilitates microgrids, which are self-contained energy systems that can disconnect from the main grid and operate autonomously during power outages or periods of instability.

Modernizing and expanding transmission infrastructure can help address location constraints. High voltage DC power lines are extremely efficient for moving large amounts of electricity over long distances. Smarter inverters and grid operating systems also enable greater integration of renewables without compromising reliability. Building out transmission will open up abundant wind and solar resources in remote areas to population centers needing clean energy.

While overcoming these limitations requires substantial investment, ongoing innovations are making reliable 100% renewable electric grids an increasingly feasible reality (Solutions to renewable energy problems, page 5).

Growth of Renewable Energy

The growth of renewable energy capacity and generation has accelerated rapidly over the past decade. According to the International Energy Agency (IEA), renewable electricity capacity is projected to increase globally by over 60% between 2022 and 2027 to over 5,000 GW (IEA). The share of renewables in global electricity generation is expected to reach 38% by 2027, up from 29% in 2020.

Several key factors are driving the growth of renewable energy globally:

• Falling costs – The costs of renewable energy technologies like solar PV and onshore wind have declined dramatically in the last decade, making them increasingly cost-competitive with fossil fuel generation (McKinsey).
• Increasing capacity – Renewable capacity additions have exceeded 280 GW per year since 2018 and are expected to reach 320 GW in 2023 as more projects come online (IEA).
• Policy support – Government policies like renewable portfolio standards, carbon pricing, and tax incentives have encouraged the deployment of renewable energy in many countries.

With renewables becoming ever more cost-competitive and increased policy support, their rapid growth is expected to continue in the coming decades.

Conclusion

In conclusion, renewable energy is widely considered to be clean energy. Renewable energy sources like solar, wind, hydroelectric, geothermal and biomass produce much fewer greenhouse gas emissions compared to fossil fuels. The expansion of renewable energy plays a vital role in climate change mitigation by displacing carbon-intensive coal, oil and natural gas.

While renewable energy technologies have some limitations like intermittency and higher upfront costs, these challenges can be addressed through a combination of technology improvements, grid modernization, energy storage, and financial incentives. With continued innovation and policy support, renewable energy capacity is expected to grow substantially in the coming decades.

The transition to renewable energy is critical for building a sustainable future. The environmental and climate benefits of clean, renewable energy highlight the importance of its ongoing expansion in electricity generation, transportation, heating, and industrial processes. Tapping into renewable resources can provide power while drastically reducing air and water pollution and carbon emissions. Renewable energy is indeed clean energy.