Energy is essential for all life and all processes that occur across the whole universe. Energy requirements in early humans were modes, they only needed fuel for fires to get warm or to cook some food. Today, humans consume a lot more energy. So they will need way more energy than the people in the past. Human energy consumption has grown steadily throughout human history. On Earth, the sun is the ultimate source of all energy that is available and used by people, animals, plants, and microorganisms. But is the sun the only energy source? Even it is most important, there are some other energy resources too.
In this lesson, we are going to learn about ENERGY RESOURCES. We will try to understand:
- What is energy?
- What are energy resources?
- Renewable vs non-renewable energy resources.
- Primary VS secondary energy resources.
- Environmental impacts of energy resources.
What is energy?
Energy is the capacity to do work and is required for life processes. It may exist in potential, kinetic, thermal, electrical, chemical, nuclear, or other various forms. The law of conservation of energy states that energy can neither be created nor destroyed - only converted from one form of energy to another.
What are energy resources?
An energy resource is something that can produce heat, power life, move objects, or produce electricity. The matter that stores energy is called fuel. Energy resources are all forms of fuels used in the modern world, either for heating, generation of electrical energy, or for other forms of energy conversion processes. Solar energy, wind energy, biomass, coal are only a few examples of energy resources. Can you think of more?
Renewable vs non-renewable energy resources
Each of the energy resources that exist can belong to one or another group, called renewable resources and non-renewable resources. What is the difference?
Renewable are those resources that will naturally replenish themselves over time, like solar, wind, plants, trees, etc. Non-renewable are those resources that will be gone forever once used, like coal, fuel, etc.
Let's discuss them and get to know more about the two groups.
Renewable energy resources
Renewable energy resources will naturally replenish themselves over time. These are:
- Solar energy
Solar energy is a renewable source of energy, comes from the sun, and is sustainable and totally inexhaustible. Solar power is converted into thermal or electrical energy. Solar energy is used for heating water for domestic use, heating space in buildings, and generating electrical energy. Solar technologies convert sunlight into electrical energy either through photovoltaic (PV) panels or through mirrors that concentrate solar radiation. This energy can be used to generate electricity or be stored in batteries or thermal storage. It is considered an environmentally friendly, the cleanest, and the most abundant source of energy because it comes directly from the Sun.
- Geothermal energy
Geothermal energy is the thermal energy in the Earth's crust that originates from the formation of the planet and from the radioactive decay of materials. Geothermal energy is simply the heat within the earth. This energy is a renewable energy source because its source is the almost unlimited amount of heat generated by the Earth's core. Geysers, hot springs, lava, and are some natural examples of geothermal energy. The environmental impact of geothermal energy is minimal.
- Wind energy
Wind power or wind energy is the use of wind to provide mechanical power through wind turbines. Wind energy, like solar energy, is a renewable energy source and will never run out. Wind power is one of the fastest-growing renewable energy technologies. The wind is used to produce electricity using the kinetic energy created by air in motion. How much energy will be extracted from the wind, depends on its speed. The higher the wind speed, the more energy. Overall, using wind to produce energy has fewer effects on the environment than many other energy sources. Wind turbines do not release emissions that can pollute the air or water (with rare exceptions), and they do not require water for cooling.
- Biomass
Biomass is a plant or animal material used as fuel to produce electricity or heat. Examples are wood, energy crops, waste from forests, yards, or farms. Biomass is a renewable energy source. Its initial energy comes from the sun, and plants or algae biomass can regrow in a relatively short amount of time. Trees, crops, and municipal solid waste are consistently available and can be managed sustainably. Biomass is a renewable energy source because trees and crops grow, and waste will always exist. It releases carbon dioxide (CO2) when burned, but considerably less than fossil fuels.
- Hydropower
Hydropower, also known as water power, is the use of falling or fast-running water to produce electricity or to power machines. This is achieved by converting the gravitational potential or kinetic energy of a water source to produce power. Hydropower is a method of sustainable energy production. Hydropower relies on the endless, constantly recharging system of the water cycle to produce electricity. Hydropower is a climate-friendly energy source, generating power without producing air pollution or toxic by-products.
Non-renewable energy resources
Nonrenewable energy resources are limited in supply and cannot be used sustainably. Once these resources are used up, they cannot be replaced, which is a major problem for humanity as we are currently dependent on them to supply most of our energy needs.
These include fossil fuels and nuclear energy. Oil, natural gas, and coal are collectively called fossil fuels. Fossil fuels were formed within the Earth from dead plants and animals over millions of years.
- Coal
Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. It is mostly carbon but also contains hydrogen, sulfur, oxygen, and nitrogen. As we said, coal is a fossil fuel. It comes from the remains of plants that died about 100 to 400 million years ago. Coal is classified as a nonrenewable energy source because it takes millions of years to form. Coal is the most abundant source of electricity worldwide, currently providing more than 36% of global electricity.
- Natural gas
Natural gas is a fossil energy source that formed deep beneath the earth's surface. It is a mixture of gases that are rich in hydrocarbons. Natural gas is mainly used as fuel for generating electricity and heat. It is not used in its pure form, it is processed and converted into cleaner fuel for consumption.
- Oil
Pressure and heat worked together to transform the plant and animal remains into crude oil. Crude oil is also known as petroleum. Oil is a non-renewable energy resource. It is the world's primary fuel source for transportation. Crude oil is a liquid fuel fossil fuel that is used mostly to produce gasoline and diesel fuel for vehicles.
- Nuclear energy
Nuclear energy is a non-renewable energy source that comes from the nucleus of atoms. Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from nuclear fission, nuclear decay, and nuclear fusion reactions. It comes from radioactive elements (mainly uranium), which are extracted from mined ore and then refined into fuel.
Primary Vs secondary resources
Primary energy resources are those found in nature. Secondary energy resources are those forms that must be produced by the conversion of primary resources.
The energy of fossil fuels, solar radiation, wind, flowing water, which are all primary, can be converted into other energy forms such as electricity and heat. That way there will be more useful to us. All energy that has been subjected to human-made transformation is considered secondary energy. Apart from electricity and heat; petroleum products, manufactured solid fuels and gases and biofuels are also secondary.
Environmental impacts of energy resources
All energy resources have an impact on the environment, but not at the same rate. They all can cause air and water pollution, damage to public health, wildlife and habitat loss, water use, land use, and global warming emissions. Non-renewable resources cause significantly more harm than renewable energy resources.
Out of all energy resources, solar, wind, biomass, and geothermal energy are considered the cleanest form of energy.
The emission of air pollutants from fossil fuel combustion is the major cause of urban air pollution. Burning fossil fuels is also the main contributor to the emission of greenhouse gases. Coal produces more pollution than any other energy source.
Summary
- Energy is essential for all life and all processes that occur across the whole universe.
- On Earth, the sun is the ultimate source of all energy.
- An energy resource is something that can produce heat, power life, move objects, or produce electricity.
- Sources of energy include solar energy, wind energy, geothermal energy, fossil fuels, nuclear energy, etc.
- Energy resources can be renewable or nonrenewable.
- Renewable resources can replenish themselves over time, and they include solar energy, geothermal energy, wind energy, biomass, hydropower.
- Non-renewable energy resources once used, can not be replaced, and they include fossil fuels and nuclear energy.
- Energy resources found in nature are primary resources.
- Primary resources are converted into secondary resources.
- All energy resources have an impact on the environment, but not at the same rate.
- Solar, wind, biomass, and geothermal energy are considered the cleanest form of energy.
- Coal produces more pollution than any other energy source.
