What Resource Produces The Most Energy?

Energy resources are natural resources that provide usable energy in one form or another. Access to affordable and reliable energy resources is crucial for modern civilization. This article will examine the major energy resources used around the world and do a comparison to determine which one produces the most energy. The key resources that will be covered are fossil fuels (coal, oil, natural gas), nuclear power, hydropower, solar power, wind power, geothermal energy, and biomass/biofuels. By looking at the total global energy production numbers for each resource, we can identify which one generates the largest quantity of energy. Understanding the scale of different energy sources allows us to make informed decisions about investing in renewable energy infrastructure and transitioning away from fossil fuel dependence. The goal is to provide a substantive overview of energy generation worldwide.

Fossil Fuels

Fossil fuels like coal, oil, and natural gas currently make up the largest share of global energy production. These energy sources come from the remains of ancient plants and animals that lived millions of years ago and were compressed under intense heat and pressure over time.

Coal is a combustible black or brownish-black sedimentary rock that is mined and burned to generate electricity. Coal-fired power plants account for about 24% of energy production worldwide. Coal is abundant and inexpensive but also highly polluting. Burning coal produces carbon dioxide, sulfur dioxide, nitrogen oxides, mercury, and ash waste that contributes to smog, acid rain, respiratory illnesses, and climate change.

Petroleum and natural gas are extracted by drilling and pumped out of the ground. Petroleum is refined into transportation fuels like gasoline, diesel, and jet fuel as well as heating oil. Natural gas is used to generate electricity, heat buildings, produce chemicals, and power vehicles. Together, petroleum and natural gas account for over 60% of global energy consumption. However, reserves are limited and production is projected to peak in the coming decades.

While fossil fuels currently dominate energy supply, they are nonrenewable and their combustion produces significant air pollution and greenhouse gases. Many countries are seeking to transition away from fossil fuel dependence given these environmental and supply constraints.

Nuclear

Nuclear energy comes from the splitting of uranium atoms in a process called nuclear fission. Uranium is a nonrenewable energy source that must be mined. Nuclear power plants use uranium fuel to produce electricity through a controlled chain reaction, where neutrons split uranium atoms which releases energy in the form of heat. This heat is used to boil water into steam that spins turbines to generate electricity.

Nuclear energy currently provides about 20% of the electricity in the United States from nearly 100 active plants. Compared to other energy sources, nuclear is one of the largest sources of carbon-free electricity. The major downsides are high upfront construction costs, the risk of accidents, and radioactive waste that needs proper long-term disposal. Overall, nuclear fission is an established energy source that provides consistent, low-carbon baseload power.

Hydroelectric

Hydroelectric power comes from dammed rivers, where the force of flowing water spins turbines connected to generators that produce electricity. Large dams are built across rivers to create reservoirs, and water flowing from the reservoir through the dam tunnels powers turbines within the dam. The amount of electricity that can be generated depends on both the volume of water flow and the height of the fall. The greater the flow and height, the more potential energy is available to convert into electricity.

Hydroelectric dams provide centralized and controllable electricity generation close to load centers. Once a hydroelectric complex is constructed, the project produces no direct waste and has low operating and maintenance costs. However, hydroelectricity has some major drawbacks and limitations. Dams and reservoirs substantially alter the natural environment and ecology of the river, which can have detrimental effects. Large dams require significant investment and take many years to construct. Suitable dam sites with sufficient flow and height are geographically limited. In addition, droughts and seasonal variations affect the amount of electricity that existing hydroelectric dams can provide.

Overall, hydroelectricity currently meets about 16% of worldwide electricity demand and is a major renewable energy source. However, most sites in developed countries with suitable hydroelectric potential have already been utilized. The future growth of hydroelectricity is expected to occur mostly in developing countries through large dam projects.

Solar

Solar energy comes from the radiation emitted by the sun. There are two main technologies for harnessing solar energy: photovoltaics (PV) and solar thermal systems.

Photovoltaic systems use solar panels made up of solar cells containing photovoltaic materials that convert sunlight directly into electricity. Large utility-scale PV systems have thousands of panels spread across acres of land. Rooftop PV systems on homes and businesses produce solar energy where it’s used, often feeding surplus power back to the grid. The cost of PV panels has declined dramatically over the last decade, leading to rapid growth in solar installations worldwide.

Solar thermal systems use mirrors or lenses to concentrate the sun’s energy to heat fluids to high temperatures. This thermal energy can then produce steam to drive turbines and generate electricity. Solar thermal plants include parabolic troughs, power towers, and dish/engines. Solar thermal accounts for a smaller share of solar generation compared to PV but offers the ability to store thermal energy to produce power when the sun isn’t shining.

Solar energy offers a clean, renewable energy source with minimal greenhouse gas emissions and water use during operation. The intermittent nature of solar power can be balanced by energy storage and interconnection over large geographic regions. With solar costs continuing to fall, PV and solar thermal have the potential to generate a substantial share of global electricity needs if deployed at massive scale.

Wind

Wind power harnesses the wind to generate mechanical power through wind turbines. Wind turbines convert the kinetic energy in wind into electrical energy that can be used for power. Wind power is considered a renewable energy source since wind is continuously replenished through natural processes and will never run out.

There are two main types of wind turbines used in wind farms – onshore wind turbines and offshore wind turbines. Onshore wind turbines are located on land and make up most of the wind power capacity installed globally today. Offshore wind turbines are located in bodies of water, usually oceans or lakes. Offshore wind farms have the advantage of stronger and more consistent winds compared to onshore, allowing offshore turbines to generate more electricity. However, constructing offshore wind farms is more expensive than onshore.

The height of onshore wind turbines ranges from about 30 meters up to 140 meters tall. The blades can be over 60 meters long. Bigger wind turbines are able to capture more wind energy. Offshore wind turbines are even larger – with towers over 100 meters tall and blades over 75 meters long. The largest offshore wind turbines today have capacities of around 12 megawatts.

Wind power capacity and generation has grown rapidly in recent decades. By the end of 2021, global wind power capacity was over 837 gigawatts. In the last decade alone, global wind power capacity increased by over 600%. Many experts project wind power to continue expanding and supplying an increasing share of the world’s electricity.

Geothermal

Geothermal power stations utilize heat energy from the earth’s core to generate electricity. This energy comes from hot water or steam reservoirs found a couple of miles or more underground. Wells can be drilled into underground reservoirs to tap steam and very hot water that drive a turbine generator to produce electricity. Geothermal power generation is comparable to other renewable resources like solar and wind.

There are three types of geothermal power plants: dry steam, flash, and binary. Dry steam plants use steam from a geothermal reservoir to directly drive turbine generators. Flash plants take high-pressure hot water, usually above 360°F, from deep inside the earth and convert it to steam to drive the turbines. Binary plants pass moderately hot geothermal water through heat exchangers, which transfer heat to a working fluid that boiled at a lower temperature than water. This causes the working fluid to flash to vapor, which then drives the turbines.

An advantage of geothermal energy is that it provides constant base-load power unaffected by weather variations. In addition, geothermal power plants release very little emissions. However, a disadvantage is that viable geothermal energy sources are only available in certain locations around the world.

Biomass

Biomass refers to organic matter that comes from plants and animals that can be used as an energy source. The most common examples of biomass used for energy include:

– Plant Materials – This includes wood, crops, grass clippings, and tree trimmings. Wood is the largest source of energy from biomass in the United States. Crops like corn and sugarcane can be fermented to produce biofuels like ethanol.

– Animal Waste – Manure from cows, pigs, and other livestock can be converted to biogas through anaerobic digestion. This biogas can be used directly for heating and cooking, or can be converted to electricity.

The carbon dioxide released when biomass is burned is offset by the carbon dioxide absorbed when the plants are growing. This makes biomass a renewable and carbon-neutral energy source. Using biomass for energy also reduces methane emissions from materials like manure by converting the methane to biogas. Overall, biomass can provide a clean and sustainable source of energy from waste materials.

Overall Comparison

When looking at total energy production from each resource worldwide, fossil fuels produce the most energy by far. In 2018, fossil fuels accounted for over 80% of total global energy production. The next largest contributor was hydroelectric at around 7%.

However, when looking at growth trends over the past decade, renewables like solar and wind have seen rapid expansion. From 2008 to 2018, solar energy production increased over 2000% and wind increased over 500%. Meanwhile, fossil fuel production grew less than 50% over the same period.

So while fossil fuels dominate current energy production, renewable sources are growing at a much faster rate and are expected to make up an increasing share of global energy in the coming decades. This is driven by concerns about climate change and fossil fuel emissions, as well as improving renewable technology and costs.

Conclusion

Fossil fuels like coal, oil and natural gas remain the dominant global energy source today due to their high energy density and historical infrastructure investments. However, their future prospects are more limited due to finite supplies and the need to dramatically reduce carbon emissions. Renewables like solar, wind and hydro offer virtually unlimited clean energy potential, but most require transmission upgrades and storage advances to overcome intermittency. Nuclear has virtually zero emissions but faces cost/safety concerns. Overall, an “all of the above” strategy utilizing each energy source’s comparative strengths will likely be needed to meet growing global energy demand in a sustainable manner.

Looking ahead, the global energy mix will continue shifting toward renewable sources as their costs fall further and supporting technologies improve. However, existing fossil fuels and nuclear will maintain roles providing dispatchable baseload power and balancing variable renewables. Energy efficiency gains will also be crucial for reducing overall demand growth. While the transition brings challenges, the potential environmental and economic benefits make pursuit of a diverse, low-carbon energy system a critical long-term goal.