• Wind and solar are the most trending types of alternative energy sources that harness sunlight and wind power to generate thermal or electrical energy.
  • Geothermal energy is the utilization of heat energy that comes from the earth’s core.
  • Hydro energy is the second-largest renewable energy source for electricity in the US and produces 6.6% of total energy.
  • Biomass is organic materials that come from plants and animals such as waste woods, crops, excreta, and even corpses.

If you look into a clean energy revolution, Wind and Solar energy come first. Renewable energy is found in sunlight, oceans, deep underground, and in the air. These sources are much less harmful to the environment, and there are quite a few types of alternative energy sources for more accessible, cleaner power.

Since they are a part of our planet’s physical structure, they are renewed naturally. You will never run out of renewable energy. These sustainable energy sources are referred to as “alternative energy” because they are an alternative to traditional fossil fuels. The advantages and disadvantages of alternative energy are to be considered.

Table of Contents

What is renewable energy?

solar energy as a types of alternative energy sources

The energy derived from the Earth’s natural resources is alternative or renewable. They are infinite and can work as an alternative energy source to fossil fuels. Even though the availability of alternative energy depends on time and weather, they provide enough power, and you can never use it all up.

The idea of utilizing alternative energy sources seems to be a new concept. But, there has been a history of alternative energy and fossil fuels going on for a while now. Renewable energy has been used for transportation, lighting, heating, and many more purposes. The wind has powered boats, windmills help grind grain, and the sun has helped to kindle fires.

Over time, we turned to cheaper and dirtier energy sources like coal and fracked gas. However, with the increased innovation of new technologies, we can capture renewable sources and use them as the primary power source.

Types of Alternative Energy Sources

1. Solar Energy

For thousands of years, we have harnessed solar energy, be it for staying warm, cultivating crops, or even drying clothes to the least. Even a study by the National Renewable Energy Laboratory concluded that in an hour, more energy falls on the Earth than what is used by the entire population of inhabitants in one year.

Today, solar energy has multiple scopes than traditional usages, such as heating homes, powering mechanics, warm water, lighting, and many more.

We can utilize solar energy through the photovoltaic effect, i.e., converting solar energy into electrical energy. Photovoltaic (PV) systems use solar cells that store energy as Direct Current (DC) in the battery. Later, this DC electricity can be used for various commercial purposes.

Solar energy can be a lifesaver with a rising crisis of petroleum products and fossil fuels. Many parts of the world have started making huge investments in solar projects. In the US alone, solar supplied almost 2% of electricity needs in 2019.

Solar energy, considering the benefits to the environment and cost-efficiency in the long term, is worth the attention.

Sunlight is functionally endless. Thus the solar energy supply is limitless.Although it is cost-effective and will save you money in the long run, the establishment cost can be high for most households.
Produces no GreenHouse Gases or other pollutants as byproductsIt needs ample sunlight and space; this can be challenging in places with little daytime or tropical climate.
Reduces electricity billsThe energy efficiency is not adequate.

2. Wind Energy

The wind breeze you feel on your hair has much more potential than you could suppose. Did you know that wind accounts for slightly more than 7% of energy generation in the US?

The Kinetic Energy from the wind can rotate turbine blades, which feed an electric generator to produce electricity.

The top wind power states in the US are Texas, California, Oklahoma, Lowa, and Kansas. These states have utilized wind energy better than others due to high wind speeds.

The wind has become the cheapest energy source since 2018 in the US. According to a report by NRDC, wind energy is responsible for 75% of cost reduction.

Image Source: https://www.nrdc.org/revolution-now
Cheapest energy sourceTransition lines are needed to carry the Wind energy, which leads to expensive installation costs.
No emission of harmful gases that degrades the environmentThe turbines generate noise and dominate the skylines.
Increment in job placements for maintaining the turbinesThe wind turbines are also a threat to birds and sometimes might even kill them from the strike while flying.

3. Geothermal Energy

The Earth’s deep core is as hot as the sun’s surface as it releases heat from radioactive decay. In simple terms, Geothermal Energy is the utilization of heat energy that comes from beneath the Earth.

Shallow ground, hot water, hot rock buried deep under the Earth, and molten rock called magma are geothermal energy resources.

Drilling deep wells through the Earth brings hot underground water along with its steam, which is then pumped through the turbine to generate electricity.

Over 20 countries use geothermal energy. The US remains the world’s largest geothermal energy producer and hosts the largest geothermal field known as “The Geysers” in California. This field spreads over 117 square km and comprises 22 power plants to produce over 1.5GW of energy.

Benefits Limitations
Since the power plant can be built underground, it leaves minimal byproducts and other footprints on the land.Extremely costly to establish power plants and drill deep wells
Geothermal energy is renewed naturally, so there is no risk of depletion on a human timescale.May increase the risk of an earthquake.

4. Biomass Energy

Image Source: https://www.eia.gov/energyexplained/biomass/

Biomass is the organic substance that comes from plants and animals such as waste woods, crops, excreta, and even corpses. Burning off that biomass or utilizing the methane gas produced by the decomposition can generate electricity with a steam turbine. The energy thus produced is known as biomass energy.

Although biomass is considered a clean and renewable fuel, recent science shows that burning biomass emits higher carbon emissions than fossil fuels. However, under the right circumstances and needs, biomass energy can also serve as a low-carbon option.

Benefits Limitations
According to the EIA report, biomass provided 5% of total energy in the US in 2017, which shows the potential of biomass if used responsibly.The burning of biomass produces carbon dioxide that is put into the air.

5. Hydroelectric Power

Hydro energy is the second-largest renewable energy source for electricity in the US and produces 6.6% of total energy.

Hydroelectric power relies on fast-flowing river water or rapidly descending water to spin the turbine blades and generate electricity. Dams are used as a funnel to guide the flowing water into the turbine blades.

Concerns are dams divert and reduce natural flows and cause environmental damage. However, the risks can be significantly reduced if planned and managed carefully.

Benefits Limitations 
It does not generate any byproducts; thus, it is a much more environment-friendly option.It disrupts natural waterways, which can affect the ecosystem that lives on them.
Hydroelectric power can be installed on even small rivers and streams.Changes in water levels or the falling of dams result in heavy flooding.

6. Ocean

The ocean can generate two types of energy – Thermal energy and Mechanical Energy. We can use the tides and flows of the ocean to generate electricity through the turbine. These tides are created by Earth’s rotation and the gravity of the Moon, so we know this energy source is here to stay.

Note that producing tidal energy requires a tidal height of at least 10 feet. People of Europe have used this method to operate grain mills for over 1,000 years. Today, this energy is used to power heavy industries and businesses.

It is estimated that tidal energy can produce 2,640 TWh per year and is enough to supply up to 93,850 US homes annually.

Benefits Limitations 
Unlike solar and wind energy, tidal energy is much more consistent.Not suitable for landlocked countries.
May disturb the ocean ecosystem.
During rough weather, the inconsistency of the tides may fluctuate the energy production rate.

7. Hydrogen

Hydrogen gas does not occur independently and is attached to other elements such as oxygen. Hydrogen fuel cells can be made by combining these two elements. As a result, it produces an electrical current. We can use the current to treat metals, produce fertilizers, refine gases, or even fuel the machinery.

It can be used as a clean energy source.It is inefficient as it needs energy for the manufacturing process.
It can be used to fuel cells similar to batteries to power vehicles.

Global Renewable Energy Consumption

The following chart shows the long-term consumption of renewable energy.

From the trend, we can see that solar energy and wind energy have been the two significant sources of energy since the year 2000.

Renewable Energy: Your Part?

As a consumer and a responsible human being, you must play a role in improving the environment through your choices. Using greener energy solutions from renewable resources is the primary step towards environmental sustainability.

Advocating for renewable energy or even using them in your home can accelerate the transition toward a clean energy future. If you are a homeowner, you have the choice to install solar panels, which will not only be beneficial for the environment but will also save you a considerable sum on electricity bills.

Switching to alternative energy sources effectively combats the global energy crisis, climate change, global warming, and pollution. By combining various types of alternative energy sources that we have mentioned above, we may be able to sustain the environment and its ecosystem for a better future.

(Last Updated on July 14, 2022 by Sadrish Dabadi)

Nina Howell is a Rewenable Energy researcher and consultant based out of Houston, Texas Area. She earned her Master's Degree in Energy and Earth Resources from Austin Jackson School of Geosciences in 2010, and a Bachelor's Degree in Environmental Science from State University of New York College of Environmental Science and Forestry in 2008. Nina has been working in the energy sector since 2011. She worked as an Energy Supply Analyst from 2011 to 2017 in Bounce Energy and then as a Research and Energy Consultant at GE Renewable Energy from March 2017 to February 2020 . Nina is a mom of 2 beautiful children who are joy to her life. She strongly believes in eco-friendly living and is vocal about renewable energy, environmental issues, water crisis, and sustainable living.