What are renewable resources?

Updated

illustration of the various renewable energy resources, including solar power, biofuel, nuclear power, wind power
Renewable resources can be used as an alternative to fossil fuels for electricity generation.

The term “renewable resources” can be thrown around and used incorrectly to describe many types of energy systems, but the most basic definition is that it is energy created using natural resources that are completely inexhaustible.

Utilizing renewable energy is extremely important for our society, as we switch to a less fossil fuel-dependent world to reduce the effects of climate change. 

What are renewable resources? 

Renewable energy takes various forms, including one of the best-known examples: solar power. It is power that is derived from the sun, whose energy will not be exhausted in our lifetimes. Alternatively, a non-renewable energy source like oil takes millions of years to form and once it’s all dug up, we won’t have any more of it for millions of years.

The use of renewable energy is expanding year after year as the world continues to realize its benefits in combating global warming. Additionally, the cost of renewable resources continues to decrease - making it more feasible now than ever before.

In fact, since 2010, the cost of solar has reduced by 80% and wind power has decreased by 40% - making both options cheaper than coal

Top five examples of renewable resources 

Solar and large-scale wind farms are probably the most well-known renewable resources, but there are other types within the U.S. energy mix. 

Examples of renewable energy resources include: 

  • Solar energy
  • Wind energy
  • Geothermal energy
  • Hydropower
  • Bioenergy

Most of the above options are impractical for homes, but can be successfully used in utility and other large-scale operations. For instance, it is more practical for you to power your home with solar panels than a wind turbine, whereas a wind farm is a great way to bring energy to an entire neighborhood. 

It’s important to note that each renewable energy source comes with its own unique set of challenges. But with each energy source, there are ways to improve their production, which we discuss below.

Solar energy 

Solar power falls into the ”renewable” category because panels can generate energy for many years by simply absorbing sunlight. Once solar panels are manufactured and installed, all they do is sit there and create energy. 

Going solar is the most practical renewable energy option for homeowners. You can connect photovoltaic solar panels to your roof and adjust the size of your system depending on the amount of energy your home needs.

One challenge with solar panels is that at the end of their lifecycle, which is typically 25-30 years, they need to be recycled - and there is currently no effective way to do this.

Learn more: Solar energy pros and cons

Wind energy

Wind power is practical if you have a farm and generate enough wind power that can then be sold to utility companies. You’ll need a large plot of land, substantial wind in your area, and the ability to pay for the high cost of installation.

Wind farms are a great way to utilize clean energy but they need to be very well-thought out. The main environmental disadvantage is the fact that they can harm animal migration patterns, especially in the water; turbines emit a low electrical current that can confuse fish and other animals that swim by them. The good news is, however, once introduced to the environment, animals should be able to adapt. 

Learn more: Wind energy pros and cons

Geothermal energy

Geothermal energy is perhaps the most untapped renewable resource. Geothermal power works by using geothermal heat pumps to use the heat from the earth’s core to generate electricity. 

Geothermal energy can most easily be used in areas with very active tectonic plates and volcano activity, such as Iceland or the west coast of the U.S. In these areas, there is a lot of movement underground and the earth’s heat makes its way to the surface. You can see examples of this with geysers as they shoot steam into the air, which is the heat building up from the earth's core. That heat is utilized to generate geothermal energy. 

One downside of geothermal is the cost - it is not yet able to compete with cheaper sources of renewable energy like solar and wind. It is very expensive to create geothermal plants and to dig deep enough to get to the hottest part of the earth.

Learn more: Geothermal energy pros and cons

Hydropower 

You can think of hydropower by imagining old water wheels that were used to power flour mills. Now, they are much larger and more sophisticated hydroelectric power generators. 

Think of the Hoover Dam in Nevada: hydropower works by harnessing the water’s energy as it rushes through the plant, powering turbines to create energy. 

Building hydropower plants has been known to displace local human populations, hinder fish population migration patterns, and exacerbate drought by keeping more water upstream so downstream populations get less

But when done in an environmentally-friendly, properly managed way, hydropower is a great source of energy. Unless there is a drought, water will always flow and is completely renewable. 

Learn more: Hydropower pros and cons

Bioenergy 

Bioenergy is a blanket term for energy sources that are derived from plant material. For example, corn can be used to create ethanol, a type of biofuel, which is then used for car or airplane fuel. 

Another application of bioenergy is wood pellets, also referred to as biomass energy or energy made from organic material. Wood pellets are derived from trees which are then burned in power plants. Because the fuel is made from plants, it is technically renewable - since the plants can be replanted and grown year after year. 

Bioenergy has the potential to be unsustainable if trees are cut down too quickly before they can regenerate. Biomass is based on the assumption that the plants that are grown to be turned into energy will also remove the carbon that they emit into the atmosphere when being burned. 

In order to make sure this process is sustainable, more trees need to be planted than are cut down to make sure that CO2 is removed at a faster rate that it is being emitted. 

Learn more: Biomass energy pros and cons

What are non-renewable resources? 

Non-renewable energy sources are usually referred to as ‘fossil fuels’ because they are, in fact, made from animal and plant fossils which have been decaying for millions of years. What makes these resources non-renewable is the fact that once they are used up, new reserves will not be created for millions of years. Hence, they will not be renewed.

The most common non-renewable resources are:

  • Natural gas
  • Oil/petroleum
  • Coal
  • Nuclear power  

Natural gas 

Often touted as a cleaner-burning fuel, natural gas still emits carbon dioxide. Carbon dioxide is an extremely harmful byproduct because it traps earth warming heat in the atmosphere. It is also getting more challenging to dig up, pushing it further away from being a cheap, “clean” resource. 

Oil

Oil is used for many things, ranging from airplane fuel to providing heat for homes. While oil and coal helped propel the industrial revolution, it might also send us to a whole new world of stress if climate change remains unchecked. 

Coal

The world's favorite heavily-polluting energy source, coal, is used globally because it historically has been reliably cheap and easy to dig up. Fortunately, renewable energy is starting to become cheaper than coal.

Nuclear power 

Many times, nuclear power is purported to be a renewable resource. But technically, it is just a zero-carbon source of energy. While it is true that the nuclear reaction that occurs to create energy can exist for years before a plant becomes too old, it produces massive amounts of radioactive waste along the way. 

Additionally, nuclear power needs a water source to constantly cool down the reactors, which then creates radioactive waste water. Radioactive wastewater contaminates water sources which can lead to unsafe drinking water or fish that cannot be eaten because they have too much radiation in them. 

High levels of radiation can lead to cancer in humans. 

Learn more: Nuclear energy pros and cons

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Why should we use renewable resources? 

Non-renewable resources like gas, oil, and coal are the main drivers of climate change. When fossil fuels are burned to use as energy sources, they expel a number of pollutants into the atmosphere, ranging from particulate matter to carbon dioxide (CO2), a heat-trapping greenhouse gas. 

CO2 does occur naturally in the atmosphere and, in fact, it is what keeps the earth at a hospitable temperature. But, when there is too much CO2 in the atmosphere, too much heat from the sun is trapped in the atmosphere and sets off cascading effects on the climate. 

There are many changes society as a whole needs to make to avert the worst effects of climate change, but one of the first steps is switching to completely renewable resources.

Renewable energy use is increasing

Slowly but surely, the U.S. is starting to adopt more renewable energy sources, partly due to its decreasing cost.

US primary energy consumption by energy source, 2019 EIA pie chart

Source: EIA

Currently, all renewable energy sources account for only 12% of U.S. energy consumption, but this figure is projected to grow to 42% by 2050, and according to the U.S. Energy Information Administration (EIA), solar is projected to be the largest renewable source in 2050.

The future of renewable resources 

Even though the world hasn’t quite figured out the best way to make renewable energy perfect, it is the best option we have for reducing the carbon footprint of humanity. Transitioning to renewable energy is imperative to reducing the amount of CO2 in the atmosphere and for reducing air pollution.

The great news is that the cost for renewable energy is decreasing and more utility companies and homeowners are choosing renewable energy options. For utility companies, there are many ways to incorporate renewable resources like solar farms, wind farms, geothermal plants, hydropower, and bioenergy. 

But if you are a homeowner and want to be in charge of your own renewable energy generation, rooftop panels can provide you that option. Rooftop solar is the most effective way to save you money and allow you to live a greener lifestyle. 

See how much solar panels will cost for your home
Looking for lists of pros and cons for other types of energy sources?

Key takeaways

  • Renewable resources are naturally replenishing and can be utilized for energy in the form of wind power and solar power.
  • Non-renewable resources like fossil fuels are still the most dominant energy sources but it is becoming cheaper to build and run renewable energy plants.
  • Along with being cheaper, renewable energy is better for the environment because they do not produce heat-trapping, climate change-causing CO2 like fossil fuels do.
 - Author of Solar Reviews

Ana Almerini

Web Content Specialist

Ana is a content specialist at SolarReviews. She uses her experience in marketing and knowledge from her master's in climate communications to research and review the solar industry.

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