What Is A Renewable Or Inexhaustible Energy Resource And How Is It Used?

Table of Contents

What are renewable energy resources?

Renewable energy resources are those that are replenished naturally over time and do not run out. They include solar, wind, biomass, hydropower, and geothermal sources. According to Penn State University, renewable energy relies on fuel sources that restore themselves over short periods of time and do not diminish [1].

Some key examples of renewable resources include:

Solar energy from the sun that can be harnessed through solar panels and concentrated solar plants
Wind energy captured through wind turbines and wind farms
Hydropower from flowing water like rivers that can spin turbines in dams

Geothermal energy from heat stored underground that can provide heating or generate electricity
Biomass from plants and organic waste that can be used to create biofuels

Unlike fossil fuels like coal, oil, and natural gas, renewable resources do not require extraction and are not finite in supply. They are considered “clean” sources of energy with lower emissions compared to traditional nonrenewable sources when generating electricity.

[1] https://www.e-education.psu.edu/emsc240/node/506

How do renewable resources differ from nonrenewable resources?

The key difference between renewable and nonrenewable energy sources is that renewable sources can be replenished in a short period of time, while nonrenewable sources take thousands to millions of years to form and cannot be replaced as quickly as they are used up. Fossil fuels like coal, oil and natural gas are nonrenewable resources that formed when ancient plants and organisms were exposed to heat and pressure over millions of years. Once these fossil fuels are extracted and burned, they cannot be replaced in a reasonable timeframe to meet our energy demands. In contrast, renewable resources like solar, wind and hydropower are constantly replenished and will not run out. The sun shines, the wind blows, and the water cycle continually renews hydropower resources. While renewable sources can be depleted if overused, they are inexhaustible over the long term if properly managed. Unlike finite fossil fuels, renewable resources are sustainable for future generations if we transition from our reliance on nonrenewable fuels.

Why are renewable resources important?

Renewable energy resources are important because they provide sustainable and clean energy alternatives to fossil fuels. Unlike fossil fuels, renewable resources like solar, wind, and hydropower don’t deplete with use and will be available for generations to come. Transitioning to renewable energy provides many benefits for the environment and public health.

According to the UCSUSA, renewable energy results in less pollution and global warming compared to fossil fuels. Burning fossil fuels like coal and gas releases greenhouse gases like carbon dioxide into the atmosphere, which trap heat and cause climate change. In contrast, renewable resources don’t release any greenhouse gases. Increasing renewable energy would significantly reduce greenhouse gas emissions and slow the rate of global warming.

The EPA also highlights that renewable energy improves public health by reducing air pollution. Fossil fuel emissions contain particulate matter and other pollutants that have been linked to asthma, heart disease, and other health problems. Renewable resources don’t emit these harmful pollutants, which would lead to cleaner air and lower rates of pollution-related illnesses.

Overall, transitioning to renewable energy is critical for creating a sustainable future and reducing the impacts of climate change and fossil fuel pollution. Renewable resources will provide clean, inexhaustible energy for generations while also benefiting the environment and public health.

Types of renewable energy resources

There are several major types of renewable energy resources that are commonly used today:

Solar energy

Solar energy comes directly from the sun and is captured using solar panels. Solar panels convert sunlight into electricity that can be used to power homes, businesses, and the electric grid (https://www.carboncollective.co/sustainable-investing/renewable-energy-resources). Solar energy does not create any pollution and is renewable. The amount of solar energy that reaches the Earth’s surface every hour is greater than the amount of energy used by the entire world’s population in a year (https://www.renewableenergyworld.com/types-of-renewable-energy/).

Wind energy

Wind energy utilizes the kinetic energy generated by wind to spin large wind turbines that power generators. Wind power is a rapidly growing renewable energy source since wind is free and abundant. Wind turbines can be built on land or offshore in large wind farms that provide energy to the electric grid (https://www.aps.edu/energy-conservation/energy-lessons-and-games/energy-lessons-and-games/26_HS-IssueOfRenewableEnergy.pdf).

Geothermal energy

Geothermal energy harnesses the natural heat inside the earth to generate steam or hot water that can drive turbines to produce electricity. Geothermal energy can also be used directly to heat buildings. While geothermal energy production emits some greenhouse gases, it is considered a renewable and sustainable energy source (https://www.renewableenergyworld.com/types-of-renewable-energy/).

Hydroelectric power

Hydropower utilizes the energy of flowing water to generate electricity. Hydropower plants capture the kinetic energy of flowing water by channeling it through turbines connected to generators. Hydropower is one of the oldest and largest sources of renewable energy (https://www.carboncollective.co/sustainable-investing/renewable-energy-resources).

Biomass energy

Biomass energy uses organic matter like plants, wood, and waste to produce electricity, heat, fuels, and products. Biomass can be burned directly or converted to liquid biofuels. Biomass is renewable as long as we grow plants and trees as fast as we use them (https://www.renewableenergyworld.com/types-of-renewable-energy/).

Solar Energy

Solar energy is harnessed from the sun and converted into electricity or heat using photovoltaic cells. When sunlight hits the photovoltaic cells, it generates an electrical current that can power devices or be fed into the electrical grid for later use. Solar energy is considered a renewable resource because the sun will continue radiating sunlight for billions of years, making it an inexhaustible source of energy on human timescales (https://planetsave.com/articles/floridians-solar-choice-ballot-effort-launched-tea-partiers-conservative-liberals/).

Some of the main applications of solar energy include generating electricity using solar panels, heating water through solar thermal collectors, and concentrating sunlight to melt salts that retain heat and generate steam to produce electricity. Solar energy can power anything from small electronics like calculators and watches to large installations like solar farms.

Solar energy is one of the fastest growing renewable energy sources due to improving technologies and decreasing costs of solar panels and components. The amount of installed solar capacity has grown an average of 50% per year over the past decade. With supportive policies and subsidies, solar power is becoming cost competitive with fossil fuels in many parts of the world. The future looks bright for expanded use of solar electricity, heat, and fuel cells to help supply the world’s energy needs.

Wind Energy

Wind energy is one of the fastest growing renewable energy sources in the United States and globally. Wind power harnesses the wind using large wind turbines, usually grouped together in wind farms, and converts the wind’s kinetic energy into electricity. The principles behind wind power have been used for centuries with technologies like windmills and sailing ships.

Most of the growth in wind power capacity is from large-scale onshore wind farms located in rural areas, but offshore wind farms are also gaining popularity. According to the U.S. Department of Energy, the average capacity of newly installed wind turbines grew 7% from 2021 to 2022, to 3.2 megawatts (MW). The total installed wind power capacity is expected to grow from 122 gigawatts (GW) in 2021 to 404 GW in 2050.

The advantages of wind power include its abundance, renewability, low operating costs and declining prices. Wind power produces no air pollution or greenhouse gases. The main limitations are intermittency, land use and impacts on wildlife. However, technological advances are helping address these drawbacks. Overall, wind energy is poised for robust growth in the coming decades as countries transition to low-carbon energy systems.

Hydropower

Hydropower refers to the generation of electricity using the energy from flowing water. The most common hydropower facilities use dams on rivers to store water in reservoirs. Water released from the reservoir flows through a turbine, spinning it, which activates a generator to produce electricity. Hydropower is a renewable energy resource because it relies on the water cycle – evaporation and precipitation – to replenish the water in the reservoir.

There are three main types of hydropower facilities:

Hydroelectric dams – These facilities use dams to control river flows and store water in reservoirs.

Pumped storage – Water can be pumped from a lower reservoir to a higher reservoir and then released to generate electricity when needed.
Microhydro – Small hydropower systems that produce up to 100 kW of electricity by harnessing small waterfalls or conduits.

Global growth in hydropower has slowed in recent years but it still accounts for over 16% of worldwide electricity generation. Most growth potential exists in developing countries in Asia, South America, and Africa that have untapped hydro resources. Existing facilities can also be upgraded and expanded to increase output. Pumped storage capacity is increasing globally to provide grid flexibility and storage capabilities.

Geothermal Energy

Geothermal energy utilizes heat from the earth and converts it into a useful form of energy like electricity. The heat within the earth’s core is very high (up to 7,000 degrees Fahrenheit) and can be harnessed in a few ways.¹

One way is through geothermal power plants, which use steam or hot water from geothermal reservoirs to turn turbines and generate electricity. There are three types of geothermal power plants – dry steam, flash steam, and binary cycle. Dry steam plants use steam directly from a reservoir to turn the turbines. Flash steam plants take hot water above 300 F from the reservoirs, convert it to steam to drive the turbines, and reuse the condensed steam. Binary cycle plants transfer the heat from the hot water to another liquid which has a lower boiling point. This causes the second liquid to vaporize, which then drives the turbines.²

Geothermal energy can also be used directly for heating homes, buildings, greenhouses, fish farms and industrial processes. This direct use of geothermal energy involved piping hot water directly from the underground reservoirs. Direct heating uses lower temperature water (100-150 F), is more efficient, and currently has a greater installed capacity worldwide than geothermal power plants.²

The use of geothermal energy has been growing at a rate of 3-4% per year over the past decade. With its ability to provide constant baseline power and advancements in enhanced geothermal systems, geothermal electricity generation has significant potential for continued strong growth in the future.¹

Biomass

Biomass refers to organic matter that comes from plants and animals. Biomass resources can be used to generate energy in several ways:

Biofuels – These include ethanol and biodiesel that are produced from crops like corn, sugarcane, soybeans etc. The biofuels can directly replace gasoline and diesel for transportation.

Biogas – Organic wastes like animal manure, crop residues, and wood wastes can decompose in anaerobic digesters to generate a mixture of gases called biogas. Biogas is comprised mainly of methane and carbon dioxide.

Wood – Wood can be burned directly for heating and energy production. Wood pellets are a concentrated form of wood that allows for more efficient transportation and burning.

Plant Growth – As plants grow, they absorb carbon dioxide from the atmosphere and release oxygen. The carbon is stored in the plant tissues and can be harvested as an energy resource.

Biomass is considered a renewable resource because plants and trees can be regrown over relatively short time periods as compared to fossil fuels that take millions of years to form.

Future of renewable energy

The future looks bright for renewable energy. Projections show massive growth in renewable energy capacity in the coming decades. According to Earth.org, solar energy capacity is expected to increase by 57% and onshore wind capacity by 47% by 2024. The International Renewable Energy Agency predicts that renewables will supply 65% of global electricity by 2030. Overcoming challenges like intermittency, storage, and transmission will be key. Widespread adoption of renewable energy will also play a crucial role in mitigating climate change and reducing carbon emissions.

Renewables face challenges like the intermittent nature of wind and solar and the need for storage and transmission infrastructure. But technological advances, policy support, and falling costs are expected to enable large-scale growth. The modular and distributed nature of renewables will also support scaling. With the right investments and policies, renewables can realistically meet a significant portion of global energy demand within the next few decades.

The growth of renewable energy is critical for combating climate change. According to the IPCC, the world must reach net zero emissions by 2050 to limit global warming. Widespread electrification paired with clean renewables will be essential to decarbonizing large sectors like transportation and buildings. Renewables’ falling costs make them increasingly competitive with fossil fuels economically. The renewable energy transition is well underway and will play a defining role in our climate future.