What Are The Most Used Energy Sources?
Energy sources are a crucial part of the global economy and our daily lives. Energy powers our homes, businesses, transportation, manufacturing, and more. Understanding the most commonly used energy sources provides important insight into energy production, security, economics, and environmental impact.
The main purpose of this article is to overview the leading energy sources that countries and citizens depend on worldwide. We will cover the major categories of energy sources such as fossil fuels, renewable sources, nuclear power, and biomass. We will also analyze key differences in energy use between global regions, the economic considerations around energy, and the environmental pros and cons of various energy sources.
This comprehensive look at global energy sources will provide readers with key background, data, analysis, and conclusions to make well-informed decisions about energy use and policy.
Fossil Fuels
Fossil fuels are by far the most heavily used energy source in the world. According to Our World in Data, in 2019 fossil fuels accounted for 84% of global energy consumption (Ritchie, 2022). The three primary fossil fuels are oil, coal, and natural gas.
Oil provides the largest share of energy worldwide. It is refined into various petroleum products like gasoline, diesel, heating oil, and many others. Oil is essential for transportation, whether it be cars, trucks, ships, or planes. The United States gets about 37% of its energy from petroleum (National Academies, n.d.).
Coal is the next leading fossil fuel globally. It is burned in power plants to generate electricity, as well as provide heat and power for industrial facilities. Around 27% of global energy comes from coal (Ritchie, 2022). However, coal use has been declining in recent years due to environmental concerns and the rise of natural gas.
Natural gas rounds out the top three fossil fuels. It is used in power generation, heating, cooking, and as an alternative transportation fuel. Natural gas accounted for 24% of the world’s energy consumption in 2019 (Ritchie, 2022). Its usage has grown rapidly due to the abundance of shale gas resources and the transition away from coal in some countries.
Renewable Energy
Renewable energy comes from natural sources or processes that are constantly replenished. Some of the most common renewable energy sources are solar, wind, hydroelectric, geothermal, and biomass. According to the Energy Information Administration, renewable energy consumption, excluding hydropower, grew by 15% in 2019. The main renewable energy sources in use today include:
Solar Energy
Solar power is one of the fastest-growing renewable energy sources in the world. It harnesses energy from the sun to generate electricity and heat. Solar technologies include photovoltaics that convert sunlight into electricity and solar heating systems that harness energy for water heating, space heating, and industrial processes. The world’s largest producers of solar power include China, Japan, Germany, and the United States.
Wind Energy
Wind power is derived from harnessing the power of wind to generate mechanical energy or electricity. Modern wind turbines convert wind’s kinetic energy into electricity. According to the Global Wind Energy Council, the global wind power capacity increased by 53% between 2014 and 2019. China has the highest installed wind power capacity, followed by the United States and Germany.
Hydroelectric Power
Hydropower is one of the oldest and most widely-used renewable energy sources. It generates power by utilizing the energy of flowing water, usually from dams, to turn turbines and generate electricity. Hydroelectricity supplies 16% of the world’s electricity. The top producers are China, Brazil, Canada, the United States, and Russia.
Geothermal Energy
Geothermal energy taps heat from under the earth’s surface to generate clean power. Technologies like geothermal heat pumps use stable temperatures near the surface for heating and cooling, while traditional geothermal power plants utilize hot water and steam reservoirs deep underground to run electric turbines. The United States, Philippines, and Indonesia lead geothermal power generation worldwide.
Nuclear Energy
Nuclear energy comes from the splitting of uranium atoms in a process called nuclear fission. Uranium is a non-renewable energy source that must be mined. There are 98 known uranium deposits that can be mined (www.eia.gov). Once mined, uranium is processed into fuel rods that are loaded into nuclear reactors. Inside the reactor, uranium atoms split apart, creating a chain reaction that produces heat and generates electricity. Nuclear power plants use the heat to produce steam that spins turbines to generate electricity.
In 2018, nuclear energy provided 10.1% of the world’s electricity from 450 commercial nuclear power reactors (https://world-nuclear.org/information-library/current-and-future-generation/nuclear-power-in-the-world-today.aspx). The USA has the most reactors at 97, providing approximately 20% of total U.S. electricity generation. France gets over 70% of its electricity from nuclear energy. Globally, nuclear generation has stayed relatively constant over the past 20 years as reactor retirements balance new reactor construction.
Nuclear energy is considered a low-carbon energy source, but it does carry risks like radioactive waste and meltdowns. Proper reactor design, construction and maintenance are critical to minimizing these risks and taking full advantage of the benefits of nuclear power.
Biomass & Biofuels
Biomass refers to organic matter that comes from plants and animals, and can be used as an energy source. The most common types of biomass used for energy are wood, ethanol, and biodiesel.
Wood has historically been used by humans to produce energy for heating and cooking through the burning of trees. Today, wood remains an important biomass fuel and accounted for 43% of biomass energy consumption in the United States in 2022 (U.S. Energy Information Administration). Modern biomass power plants burn wood waste or chips to generate electricity.
Ethanol, made from fermenting plant sugars from corn and other crops, is a major renewable transportation fuel. In 2022, ethanol accounted for 49% of biomass energy use as a biofuel blended into gasoline for vehicles (U.S. Energy Information Administration). Ethanol production has rapidly grown in recent decades as countries seek to increase renewable energy usage and reduce greenhouse gas emissions from transportation.
Biodiesel is another common biofuel, produced from oils like soybean oil, canola oil, and recycled cooking oil. Biodiesel can power diesel engines with little or no modification. While biodiesel makes up a small percentage of overall biofuel production today, it offers an renewable diesel alternative as countries aim to decarbonize transportation.
Regional Differences
The energy mix varies significantly by country and region. According to Our World in Data, in 2019, the Middle East had the highest share of energy from oil at nearly 60%. The region is a major oil producer. North America relied heavily on natural gas, which accounted for over 30% of its energy mix. Europe had the most diverse energy portfolio, with the largest share coming from nuclear at 25%. Meanwhile, Africa had the highest share of renewable energy at nearly 50%, mostly from hydroelectric dams.
China relies predominantly on coal, which provided over 60% of its energy in 2019 according to the International Energy Agency (IEA). However, China has been rapidly increasing deployment of renewables. The United States has a more balanced energy mix, with natural gas at 31%, petroleum at 30%, coal at 23%, nuclear at 8%, and renewables at 11% as of 2019 per IEA data. In the European Union, renewables accounted for 19% of energy while fossil fuels supplied over 50%. India still gets about 75% of its energy from coal, although it is aiming to increase its renewable energy capacity to 500GW by 2030.
Overall, developed countries tend to have more diversified energy portfolios and higher contributions from nuclear and renewable sources. Developing nations often rely more heavily on fossil fuels, particularly coal and oil. But renewable energy is growing quickly in some developing regions like Africa and parts of Asia.
Environmental Impact
The environmental impact of different energy sources varies greatly. Fossil fuels like coal, oil, and natural gas produce significant amounts of greenhouse gas emissions like carbon dioxide when burned. These emissions contribute to climate change by trapping heat in the atmosphere. According to the EPA, the electric power sector accounted for 25% of U.S. greenhouse gas emissions in 2020, with a majority coming from burning fossil fuels (The Advantages and Disadvantages of Renewable Energy).
In contrast, most renewable energy sources like solar, wind, and hydropower generate little to no global warming emissions. Switching to renewables can help mitigate climate change and reduce air pollution. However, some renewables do have environmental downsides. For example, large hydropower dams can disrupt river ecosystems, and wind turbines pose a threat to birds and bats (Pros and Cons of Renewable Energy Sources).
Nuclear power generation does not directly produce air pollution or carbon emissions. However, accidents at nuclear plants can result in radioactive contamination. Nuclear waste also remains radioactive for thousands of years and requires safe long-term disposal. Overall, most experts agree renewables and nuclear cause less environmental harm than fossil fuels, but each energy source has unique pros and cons.
Energy Economics
The cost of energy from different sources varies significantly. According to the International Energy Agency, the estimated levelized cost per megawatt hour (MWh) in 2020 for onshore wind was $37, solar PV was $39, gas combined cycle was $47, and nuclear was $68 (Projected Costs of Generating Electricity 2020). Cost factors include capital costs, fuel costs, operating and maintenance costs. Renewable energy sources like solar and wind have become increasingly cost competitive with traditional sources.
Fossil fuels like natural gas and coal have relatively low fuel costs but higher capital costs. The availability and price of fossil fuels fluctuates based on supply and demand. Instability in oil producing regions can cause energy price spikes. Renewable energy production costs have dropped steadily as technology improves. Government incentives and long term contracts have made renewable energy affordable and minimized price volatility (Cost of electricity by source).
Nuclear energy has very low fuel costs but extremely high capital costs. New nuclear plant construction has stalled in part because cheaper energy alternatives exist. Energy storage technology for renewables continues to improve. With greater grid energy storage capacity, intermittent renewable sources can better meet peak energy demands (Types of Energy Ranked by Cost).
Energy Policy
The energy policies of countries vary widely depending on their geographic location, natural resources, economic priorities, and environmental concerns. Policies play an important role in influencing which energy sources are utilized and the pace of transition to cleaner sources.
In the IEA, energy policy is often focused on security of supply, affordability, and sustainability. The IEA Policy Database tracks thousands of energy policies across IEA member countries and many partners.
Some common policy tools used by governments include:
– Regulations like fuel economy standards for vehicles
– Subsidies and tax breaks for renewable energy sources
– Carbon pricing mechanisms like emissions trading systems or carbon taxes
– Initiatives to support clean energy R&D and infrastructure
The mix of policies varies widely between countries. For example, Norway uses its large hydro and oil resources to export energy while promoting EVs domestically. India is focused on expanding energy access with a goal to increase renewable sources. China‘s policies aim to curb air pollution by reducing reliance on coal.
Conclusion
In conclusion, fossil fuels like coal, oil and natural gas remain the dominant energy sources worldwide due to their high energy density and historically low costs (source). However, continued use of fossil fuels is problematic due to pollution, climate change impacts and finite supplies. Renewable energy sources like solar, wind and hydropower are growing rapidly as costs decrease, but most renewables still require government subsidies to compete with fossil fuels (source).
Looking ahead, a mix of energy sources will likely be needed to meet future demand while transitioning to a more sustainable energy system. More investment is needed in renewables, battery storage, grid modernization and energy efficiency to accelerate this transition. Energy policies such as carbon pricing can help account for the external impacts of fossil fuels. Overall, diversifying the energy mix with an increased focus on renewables and nuclear is critical for energy security, affordability and mitigating climate change (source).
