What Is a Renewable Resource?

What Is a Renewable Resource?

A renewable resource is a resource that can be replenished naturally over time. As a result, it is sustainable despite its consumption by humankind.

Renewable resources are considered especially important for their potential to replace non-renewable, or finite, resources in the production of energy. Additionally, renewable resources can offer cleaner energy solutions than those provided by non-renewable resources such as coal and fossil fuels.

Examples of renewable resources include the sun, wind, water, the earth’s heat (geothermal), and biomass.

Understanding Renewable Resources

A renewable resource is a resource of which there is an endless supply because it can be replenished. The sun, the wind, and geothermal heat are considered inexhaustible and therefore are examples of renewable resources.

Water is also considered a renewable natural resource, as long as there is precipitation. Changing climate patterns have shown the need for conservation efforts to protect water supplies.

Other natural resources are considered renewable even though some time and effort must go into their renewal. In addition, most precious metals are considered renewable because they’re reusable. Since they are not destroyed during their extraction and use, they can be recycled.

Unlike renewable resources, once a non-renewable resource is depleted, it cannot be recovered. As the human population continues to grow and finite resources become increasingly scarce, the demand for renewable resources increases.

Renewable Resources Used for Energy

Fossil fuels have been used since the late 1880s to produce the energy we use. Renewable resources such as hydropower and wood have been used much longer. In fact, they were the two primary renewable energy resources up to the 1990s.

In the years since, renewable energy production has come increasingly from biomass, geothermal, solar, water, and wind resources.

Renewable resources that can replace fossil fuels in the production of energy are a major focus of nations around the world. The challenges for successful renewable energy production include reliability and expense.

A great deal of research is taking place to determine the viability and best implementation of renewable energy on a mass scale.

Types of Renewable Resources

Sun

Sunlight is a widely recognized renewable resource. In fact, it’s been used throughout human history to warm shelters, dry and cook foods, and heat water. Different technologies exist and continue to be developed to collect and convert solar radiation into heat energy that can be used for various purposes.

For example solar photovoltaic (PV) devices, or solar cells, change sunlight into electricity. Depending on the number of solar cells in use, they can power small appliances or provide the electricity for many homes

The challenge with using sunlight for our energy needs is that it can vary and, at times, be unreliable. The availability of sunlight depends on time of day, existing weather conditions, season of the year, and geographic location.

Wind

Wind has a direct relationship to the sun. Daily winds result when the sun’s heat is captured unevenly by the varying surfaces on the earth, including oceans and other water masses. Air above land heats up faster than air above water during the day when the sun is shining. That warm air expands and rises. Cooler air takes its place. This creates wind.

In earlier years, windmills were used across the U.S. to capture energy and pump water from wells. They still exist in some farming areas to provide livestock with water.

Today, wind is harnessed to produce electricity. Wind flows over blades in wind turbines. The blades turn and that drives an electric generator. In turn, that generates electricity.

Typically, wind turbines don’t produce emissions capable of polluting the air or water. Also, they don’t need to be cooled by water. Though rare, they can have some negative effects on the environment if they leak lubricating fluids or catch fire. They can also impact bird life and species.

In 2021, wind turbines provided about 9.2% of total U.S. utility-scale electricity generation.

Water

Hydropower is the energy produced by water. It was an early renewable source of energy even before it was used to generate electricity. For example, hydropower turned paddle wheels on rivers to mill grain and lumber. Changes in precipitation and lack of water due to droughts can affect hydropower production.

Hydropower was used to generate electricity in the U.S. beginning in 1880. Today most of the nation’s hydroelectricity is produced in facilities located at large dams built in the 1970s.

Until 2019, hydropower was the largest source of total annual renewable electricity generation in the U.S.

In 2021, hydroelectricity accounted for 31.5% of total utility-scale renewable electricity generation.

Geothermal

Geothermal is a renewable resource that uses the earth’s heat to generate power. Hot springs heated by the earth have been used for centuries for bathing. Geothermal energy has also been used, and still is, for district heating systems.

Geothermal energy is used to generate electricity, as well. Power plants for this purpose are built below ground, within approximately a mile of the earth’s surface.

Seven U.S. states have geothermal power plants. In 2021, they produced approximately 16 billion kilowatthours (kWh) of electricity. That equals about 0.4% of total U.S. utility-scale electricity generation. Those states are California, Oregon, Nevada, Idaho, Utah, New Mexico, and Hawaii.

Geothermal heat pumps are another way to use the earth’s heat. They transfer heat from the ground (or water) into buildings during the winter and reverse the process in the summer to aide in heating and cooling.

Biomass

Renewable organic products that produce energy are referred to as biomass. The process of photosynthesis uses energy from the sun to convert biomass resources into chemical energy.

In 2021, biomass provided nearly five quadrillion British thermal units (Btu) and about 5% of total primary energy use in the United States.

Biomass renewable resources include wood and wood waste, agricultural crops and waste (which are mainly used for biofuel), municipal waste including paper, cotton, food, and yard waste, and animal manure and sewage.

Biofuel refers to liquid fuels and blending components produced from feedstock biomass materials. Most biofuels are used as transportation fuels, but they may also be used for heating and electricity generation. This renewable resource has become more prevalent in recent years as an alternative to non-renewable resources such as coal, oil, and natural gas.

In 2021, the U.S. produced about 17.5 billion gallons of biofuels. It used about 16.8 billion gallons. In addition, the U.S. was a net exporter of about 0.8 billion gallons of biofuels. The fuel ethanol accounted for the largest part of those exports.

Although prices are still high for biofuel, some experts project that as the prices of fossil fuels increase, the price of biofuel will become more competitive.

Renewable Resources vs. Non-Renewable Resources

Renewable Resources

Renewable resources are those resources that continue to exist despite being consumed or can replenish themselves over a period of time even as they are used. They include the sun, wind, water, geothermal, and biomass.

The disadvantage of renewable resources is that they may not be available for use when needed.

For example, the ability to collect and use solar energy is limited at night and when the sky is overcast. The continued availability of water depends on ongoing precipitation and weather conditions.

Renewable resources are considered to have less of a negative impact on the environment.

Non-Renewable Resources

Non-renewable resources are those resources that are considered finite due to the extremely long time it takes for nature to create them. Once depleted, they become unavailable. They include coal, natural gas, and oil.

The advantage of non-renewable resources is that they’re readily available now and the infrastructure for their use exists to produce power on demand.

However, they have a greater, negative environmental impact than renewable resources. The heat trapped by carbon dioxide gas when coal and oil are burned contributes to the atmosphere’s rising temperature and global climate change.

Activists, consumers, and government leaders promote renewable energy as a way to generate needed power without the emissions that are warming the planet and threatening life on earth.

Special Considerations

A Global Trend Toward Renewable Resources

Renewable resources have become a focal point of the environmental movement, both politically and economically. Energy obtained from renewable resources puts much less strain on the limited supply of fossil fuels, which are non-renewable resources.

The problem with using renewable resources on a large scale is that they are costly and, in most cases, more research is needed to determine how to use them most cost-effectively.

Beyond their limited supply, energy sources such as fossil fuels damage the environment when produced and consumed and contribute to global warming. The first major international accord to curb carbon dioxide emissions and global warming was the Kyoto Protocol, signed in 1997. More recently, global powers met in Paris in 2015 to pledge emissions reductions and focus on higher reliance on renewable resources for energy.

Incentives for Use

Incentives can encourage the use of alternative energy. For example, energy taxes place a surcharge on fossil fuels. This can make prices of renewable resources more competitive and attractive. As a result, people may be more inclined to use renewable energy.

Green funds, which are investment vehicles such as mutual funds, support eco-friendly and sustainable companies by investing in them. This also helps to promote environmental awareness.

These incentives seem to be having an effect. According to the U.S. Energy Information Administration (EIA), in 2021, renewable energy provided approximately 12.6 quadrillion British thermal units (Btu). This represented 12% of total U.S. energy consumption.

The electric power sector consumed around 59% of U.S. renewable energy in 2021, and approximately 20% of U.S. electricity generation came from renewable energy sources.

State and federal governments have encouraged more biofuel consumption with requirements and incentives for the use of renewable energy. The EIA anticipates that U.S. renewable energy consumption will continue to increase through 2050.

The Bottom Line

Renewable resources include the sun, the wind, water, the earth’s heat (geothermal), and biomass.

Renewable resources are natural resources that replenish themselves over time or exist on a continual basis. In recent years, they’ve been of special interest for the vital role they can play in replacing non-renewable resources such as fossil fuels in the production of energy. They’re also seen as having less of a negative impact on the environment.

Of course, renewable resources were used for thousands of years before non-renewable resources such as coal and oil began to be used used extensively in the late 19th century.

Due to the finite nature of coal and oil, plus the threat from climate change, the world community is focusing on the greater use of renewable resources to meet energy needs.