What Are The Major Nonrenewable And Renewable Sources Of Energy?
Nonrenewable Energy Sources
Nonrenewable energy sources come from finite resources that will eventually dwindle, becoming too expensive or too environmentally damaging to retrieve. The most significant sources of nonrenewable energy are fossil fuels (oil, natural gas, and coal) and nuclear power.
Fossil fuels formed when prehistoric plants and animals died and were gradually buried by layers of rock over millions of years. Their remains were converted into crude oil, natural gas, and coal. Fossil fuels are currently the world’s dominant energy source, providing around 80% of all energy consumed globally. However, reserves are limited and non-renewable.
Oil, often referred to as “black gold,” is a liquid fossil fuel that can be refined into fuels like gasoline, diesel, and jet fuel. It has thousands of uses and is a raw material for many chemical products like pharmaceuticals, plastics, and solvents. Global oil consumption has steadily increased over time as economies have expanded and transport systems have developed and modernized. However, oil reserves are finite and concentrated in a few regions around the world.
Natural gas is a mixture of hydrocarbon gases formed alongside oil underground. It can be burned for heating, cooking, electricity generation, and fuel for vehicles. Natural gas emits 50% less CO2 than coal to produce the same amount of energy. It has become popular as a “bridge fuel” while renewable energy capacity grows. But natural gas reserves are also finite and face supply constraints.
Coal is a solid fossil fuel formed from plant matter buried underground and subjected to high heat and pressure over millions of years. It fueled the Industrial Revolution and today generates roughly 30% of the world’s electricity. However, coal is the most carbon-intensive conventional fuel and a major contributor to air pollution and climate change. Coal mining also causes environmental damage. Global coal reserves may run out within the next century as consumption continues rising.
Nuclear energy comes from splitting uranium atoms in a controlled chain reaction to produce heat, which is used to generate electricity. Nuclear provides around 10% of the world’s electricity. It produces negligible greenhouse gas emissions and can ensure energy security by relying on domestically sourced uranium. However, uranium is a nonrenewable resource that will eventually be depleted. Nuclear also faces challenges with safety, radioactive waste storage, and high costs.
Oil
Oil is a nonrenewable fossil fuel that is found underground and drilled from wells and offshore rigs. It is one of the world’s leading sources of energy and the most used fuel for powering various modes of transportation including cars, trucks, ships, and airplanes. Oil is also commonly used for heating homes and businesses as well as generating electricity.
Oil is formed over millions of years from the remains of tiny plants and animals (microorganisms) that lived in ancient seas. As these microorganisms died, they sank to the bottom of the sea and were buried by sediment and sand. Over very long periods of time, the increase in heat and pressure transformed the organic matter into oil and natural gas.
Oil can be extracted by drilling down through layers of sedimentary rock until an oil reservoir is reached. Modern drilling methods allow wells to be drilled that are over 30,000 feet deep both on land and underwater in oceans. Pumps are then used to bring the crude oil to the surface. Once extracted, crude oil is transported via pipeline, oil tankers, trucks and trains to refineries where it is processed and refined into various fuels like gasoline, diesel, and heating oils.
Oil powers the vast majority of vehicles globally and is critical for transportation and trade. It also remains an important fuel for heating and electricity generation. However, oil is a finite resource and reserves are being depleted faster than new ones are being discovered. Conservation efforts and a transition to renewable energy sources will be needed to reduce our dependence on oil in the coming decades.
Natural Gas
Natural gas is a fossil fuel that forms deep beneath the earth’s surface. It is extracted from underground deposits and wells by drilling. Natural gas is a nonrenewable energy source because it takes millions of years to form.
Natural gas is composed mainly of methane, but also contains other hydrocarbons like ethane, propane, and butane. It can exist on its own or be associated with crude oil deposits.
Natural gas has become an important source of energy in the United States and around the world. After extraction, it goes through a purification process to remove impurities and separate the methane. The gas is then piped through transmission pipelines to its end destinations.
The primary uses of natural gas include heating, cooking, and electricity generation. Over half of American homes use natural gas for space and water heating. It is also used as a cooking fuel for stoves and ovens. For electricity generation, natural gas is burned in turbines to spin generators.
Natural gas emits fewer emissions than other fossil fuel sources when burned. However, there are concerns around methane leaks during its production and transportation. Overall, natural gas is a flexible, abundant, and relatively clean burning fossil fuel, but supplies are limited.
Coal
Coal is a nonrenewable energy source that is mined from underground reserves around the world. It is one of the most abundantly available fossil fuels globally. Coal has played an important role in the development of modern societies, providing an efficient and relatively inexpensive energy source for electricity generation, steel production, and other industrial processes.
Coal is formed from decomposed plant material that was buried underground and exposed to heat and pressure over millions of years. The energy we get from coal today originally came from the energy of the sun that was absorbed by plants during photosynthesis long ago. There are different types of coal, depending on the length of time and types of conditions they were exposed to during formation. The harder the coal, the more energy it contains.
Most coal today is used for electricity generation in power plants. Coal-fired power plants burn coal to make steam. The steam then turns turbines which generate electricity. Coal has been a major energy source for electricity because it is relatively inexpensive, abundant, and has a high energy density. Coal also plays an essential role in steel production, providing the carbon required during the smelting process.
While coal has been an important energy resource, it also has some environmental challenges. Coal mining can impact land and water resources. Burning coal produces air emissions including carbon dioxide, a greenhouse gas linked to climate change. Coal also contains impurities like sulfur and mercury that are released when it combusts. Technologies to capture these pollutants have been developed but are not widely deployed. Overall coal remains a controversial energy source due to its environmental impacts.
Nuclear
Nuclear power plants use uranium as a fuel source for nuclear fission to generate electricity. Uranium atoms are bombarded with neutrons, causing them to split apart into lighter atoms and release energy in the form of heat. This heat is used to boil water into steam that spins a turbine to activate an electric generator.
Nuclear fission produces a great amount of energy from a small amount of fuel, making it a very dense source of power. Uranium is considered a nonrenewable resource because it cannot be readily replenished on a human timescale. Uranium ore is mined from the ground, then goes through an enrichment process to increase the uranium-235 isotope used in reactors. There is an abundant supply of uranium in the earth’s crust, but extraction becomes more challenging over time as high-grade ore deposits diminish.
Nuclear energy accounts for about 10% of electricity generation worldwide. Advocates argue it produces reliable baseload power with zero emissions. Critics counter that safety concerns, radioactive waste, and proliferation risks limit its expansion. Nuclear disasters like Chernobyl and Fukushima have undermined public support in some countries. Overall the future use of nuclear power remains debated and varies greatly by nation.
Renewable Energy Sources
Renewable energy comes from natural sources that are constantly replenished. Some of the main renewable energy sources are:
Solar Energy
Solar energy comes directly from the sun. It can be harnessed through solar panels that convert sunlight into electricity. Solar energy is increasingly being used for powering homes, businesses, and the electric grid.
Wind Energy
Wind turbines convert the kinetic energy of wind into mechanical power. Wind farms with many turbines are being used to generate clean electricity. Wind power is one of the fastest growing renewable energy sources.
Hydroelectric Power
Hydropower harnesses the energy of flowing water to generate electricity. Dams on rivers or water reservoirs can be used to control water flow for electricity production.
Geothermal Energy
Geothermal energy taps into the natural heat inside the earth to produce steam to drive turbines and generate power. It provides clean, renewable energy from the earth’s vast thermal resources.
Biomass Energy
Biomass refers to organic material from plants and animals. It can be used to produce transportation fuels, generate electricity, and provide heat. Common examples are wood, crops, landfill gas, and alcohol fuels.
Solar
Solar energy is harnessed from the sun and converted into thermal or electrical energy. The most common way to capture solar energy is through the use of photovoltaic solar panels. These panels contain solar cells made from semiconducting materials that convert sunlight directly into electricity via the photovoltaic effect.
Solar panels can be installed on residential and commercial buildings, either on rooftops or integrated into facades and windows. This allows buildings to generate some or all of their own electricity from the sun. Larger utility-scale solar power plants also use vast arrays of solar panels to generate electricity at scale that is fed into the electric grid.
Solar energy offers a clean and renewable way to provide electricity with zero emissions. The amount of sunlight that reaches the Earth’s surface in one hour is enough to power human civilization for an entire year. While sunlight is free and unlimited, the initial investment required for solar panels can be cost prohibitive. However, solar costs have dropped dramatically in recent decades making it an increasingly affordable clean energy source.
Wind
Wind power harnesses the kinetic energy generated by air flow to produce electricity without emitting greenhouse gases. Wind turbines convert the kinetic energy of wind into mechanical power that runs a generator to produce electricity. The amount of energy generated depends on the turbine’s size and the wind’s speed through the rotor. Utility-scale wind farms consist of many individual wind turbines that are connected to the electrical grid. With turbines getting larger and more efficient, wind has become one of the fastest growing renewable energy sources worldwide.
Wind turbines consist of blades attached to a rotor that spins a shaft connected to a generator. The turbine is mounted on a tall tower to take advantage of faster wind speeds at higher altitudes. The blades are aerodynamically designed to capture the maximum energy from the wind. As wind pushes the blades, the rotor spins, converting the kinetic energy of the wind into rotational kinetic energy. This rotational motion turns an electrical generator to produce electricity.
Hydroelectric
Hydroelectric power captures the energy from flowing water to generate electricity. It relies on dams built across rivers to create reservoirs and control water flow. As water in the reservoir flows through the dam, it turns turbines connected to generators that convert the kinetic energy of the moving water into electrical energy. Hydroelectric power provides around 16% of the world’s electricity from facilities located across the globe, however it does have some environmental impacts due to the damming of rivers. Overall, hydroelectricity is considered a renewable and sustainable energy source that will continue playing a major role in the global renewable energy mix.
Geothermal
Geothermal energy harnesses the heat within the earth to generate sustainable energy. Deep beneath the surface, radioactive decay in the planet’s core produces tremendous amounts of heat. This geothermal energy can be accessed by drilling wells into reservoirs of hot water and steam that exist naturally in underground rock. The steam rising to the surface from these geothermal reservoirs can be tapped and used to drive turbines attached to power generators, producing electricity.
In particular, geothermal power plants rely on steam from deep underground reservoirs to run their generators. Wells are drilled 1 or 2 miles deep into geothermal reservoirs to provide access to hot pressurized water and steam. The steam is piped up to drive the turbine, which activates a generator to produce electricity. The steam is cycled through the plant and any remaining water is returned down an injection well into the reservoir to be reheated, continuing the cycle. Geothermal power plants run steadily 24/7, as the steam flow is constantly replenished from the earth’s heat below. This makes geothermal a reliable and sustainable source of renewable energy.
