Alternative Energy Sources: Our Top 15 to Know

Do you want to learn about alternative energy sources? Consider some of the more well-known and some less popular options.

All of these energy sources have unique benefits that we can use now and in the future. As we run out of non-renewable resources, these alternative sources will keep the world alive.

Keep reading to learn about these alternative sources of energy and why renewable energy matters.

1. Airborne Energy

Airborne energy, what is it?

Airborne energy or airborne wind energy uses wind to generate energy. There are two principles to understand this alternative energy source. The first principle is the most popularly known. It involves a propeller turbine, which has a generator typically in its flying wing. The second one involves a kite – yes, a kite! (1)

Both principles are also beneficial because they involve less material and leave less carbon dioxide footprint. Furthermore, AWE can operate in high full load hours, meaning it can constantly produce electricity, day or night. Basically, airborne energy is an excellent way to harvest energy at higher altitudes. Winds can be more powerful up high, and they can be steadier and more efficient than wind turbines on the ground.

2. Biofuels

Biofuels are a type of biomass energy, and they are cheaper while netting more energy. Using biofuels is an excellent alternative to traditional transportation energy, such as gasoline. Biofuels are even being used in the airline industry:

In addition, the discovery of glycerol may prove useful, especially in overcoming difficulties in the manufacturing process (2).

In 2024, a commercial biofuel plant is projected to open using their licensed technology. To learn more about the future of biomass energy and its most important pros and cons, you can check out this article.

3. Floating Turbines

Alternative energy sources like floating turbines are also useful. So, how How does it work?

Floating turbines work exactly as it sounds – turbines floating on the water! Conventional wind farms take a lot of space and can eat up the whole coastline. And, what place on earth has a vast, wide-open space? Yup, that’s the ocean. Fun fact, 71% of the earth’s surface are oceans (3).

For locations with limited land space but has access to the ocean and have wind rates can take advantage of floating turbines. However, there is a drawback – this alternative source of energy is expensive! Many countries don’t have the means to invest and maintain a floating turbine system.

4. Geothermal Energy

Geothermal is one of a few alternative sources of energy that you can always use. You don’t have to worry about weather patterns, such as with wind and solar energy; geothermal energy taps the heat inside the Earth and generates steam that Geothermal power plants will convert to clean and ready-to-use electricity.

Many countries that are near the tectonically active regions have or use geothermal energy. In fact, Iceland gets about 90% of its heating from geothermal energy (2). Just like floating turbines, harnessing geothermal energy requires a high upfront cost. To learn more about the pros and cons of geothermal energy, you can read more here.

5. Hydroelectric

Hydroelectric is another thing to consider when looking at alternative energy sources.

While other alternative energy sources rely on wind, sun, and heat, hydroelectric relies on hydro (aka water), particularly the water movement or flow to generate power. It’s not a new form of energy source – it’s been around for millennia! (3). So, how does water movement transformed into electricity?

A typical hydropower plant or facility pushes the water through a pipe or opening with built-in blades. As the water flows through, the blades turn, creating a turbine that spin’s the generator for electricity production. Interesting, right? Hydroelectric technology is common in water reservoirs and dams, but can also be applied to open, run-of-the-river systems.

There are many benefits of using hydroelectric, one of which is we don’t have to worry about losing that energy in the future. With clever innovations in this field, the reasons why renewable energy is important will only continue to grow.

6. Hydrogen

Another energy source to consider is hydrogen, which offers many benefits like no carbon dioxide emissions.

Hydrogen may not come to mind when talking about alternative energy sources. But, it can become a top energy choice for the future (4). This is partly because we can produce hydrogen by using sustainable and renewable sources. And, hydrogen has different applications, ranging from car fuel to heating.

As a matter of fact, rockets use hydrogen for fuel because of the element’s high energy content (5).

7. Solar PV

Solar photovoltaic (PV) energy is what you think of when you think of solar panels. Many ask, “Why is solar energy important?” Well, put simply, these panels can collect and store energy from the sun. If you live somewhere with a lot of sun, this energy source could be an excellent option.

If you live in a region that doesn’t experience much sunlight, unfortunately, solar may not be viable for you. While there are many positives with this alternative energy source, there are several disadvantages of solar energy to keep in mind.

8. Solar Roads

Capturing the sun’s power is no longer limited to installing solar panels on the roof because countries such as the Netherlands have developed roads that can harness solar energy.

Yup, you read that right. Instead of asphalt, these roads have solar PV panels. These roads can be a great energy source for cities and towns with many streets. Unfortunately, dirt and dust can reduce 0.5% of energy efficiency for every degree (6). There is also a huge debate on its durability for long-term use as the panels are subjected to high volume of weight on a daily basis.

Plus, there are heating concerns. Solar panels require air circulation. That’s why most residential solar-powered homes have significant clearance between the panels and roof.

9. Solar Thermal

Another energy source that harnesses the power of the sun is solar thermal energy. Just like solar PV, it captures the sun’s radiation. The difference is, as this alternative source of energy’s name suggests, use heat for electricity production.

Solar thermal systems don’t use solar PV panels. They have reflectors or mirrors, receivers, and heat-transfer fluid. Reflectors are responsible for redirecting the sunlight to the receiver. The receiver will then heat up the liquid in high temperatures. The fluid will then move to a tank and generate steam (7).

During low solar radiation, some solar thermal power plants have a hybrid system, wherein they use natural gas to supplement the heat scarcity.

10. Solid Biomass

Bioenergy is another alternative to fossil fuels. But, rather than relying on water, sun, or heat, bioenergy uses what they call “biomass.” It is derived from food waste, microalgae, crop wastes, woody energy crops, forest residues, and purpose-grown grasses (8).

Many power plants convert biomass into biofuel like ethanol and biodiesel, which is commonly used to power aircraft and vehicles. Some use biomass for heat and electricity. To harvest energy, power plants usually subject biomass to burning or bacterial decay. Others transform the biomass into a liquid fuel first.

11. Space Solar

If you live in a place without much direct sunlight, you may benefit from space solar energy. This type of energy could help compensate for growing demands and a growing population (9).

But, how does space solar energy even work?

Space solar systems use satellites that are equipped with solar panels and giant mirrors. And, just like a sci-fi movie, the satellite will wirelessly beam the collected solar radiation back to earth. The reason why space solar energy is a better choice is, well, there is no uninterrupted access to solar radiation – no clouds to worry about!

With technology increasing rapidly, the ability to leverage space for our energy needs is no longer out of the question.

12. Tidal

Similar to hydroelectric, tidal energy is derived from the movement of water. But there’s an external factor, the moon and the sun’s gravitational effect on earth, AKA tides.

There are different ways to capture and convert tides to energy, but the three most common are tidal barrages, tidal turbines, and tidal fences. All three take the advantage of the rise and fall of the tides. The reason why tides are utilized as a renewable energy source is that ocean current is denser than air, meaning it applies more force to the turbine (10).

What sets tidal energy apart from other renewable energy sources like solar energy is predictability – scientists monitor the tide on a daily basis!

13. Waves

Similar to tidal energy and hydroelectric, we can also harness energy from waves. Although relatively new, this renewable energy source is making waves and shows huge tremendous potential because waves contain a lot of energy. In the United States alone, waves can generate a theoretical annual energy output of 2.64 trillion kilowatt-hours (11). That’s 64% of the 2019 electricity generation from other energy sources!

But unlike tidal power, a WaveSub can sit under the water and collect energy from the waves. This differs from tidal energy, which uses small turbines.

14. Wind Turbines

Wind turbines are one of the most well-known alternative energy sources. A wind farm can collect a lot of energy given the right circumstances, but some turbines can be quite tall. While they do take space, they’re a great source of energy in areas with a lot of wind.

If you’re interested in learning more, our guide on wind energy pros and cons can help you discover the potential of this exciting industry.

15. Wood

As we’ve mentioned, wood is a type of biomass, which can be used in making biofuels like ethanol. Plus, using wood for energy has been around for years. A few types of wood that can be used for energy production are firewood, pellets, and chips. Even as other alternative energy sources appear, wood will remain a standard choice.

Moreover, turning wood waste into a more economically friendly energy source also means more electricity access for many people, and we can finally clear landfills.

FAQs

• Which Industry Invests the Most in Alternative Clean Energy Sources?

  The industry that invests the most in alternative clean energy is now big oil companies.

  For example, BP announced that they plan to produce net-zero carbon emissions by 2050 (12). This can only be done with significant investments in clean alternative energies, but in many cases, investors meet these changes with resistance.

• Why is it Important to Develop Alternative Energy Sources?

  It’s important to develop alternative energy sources because it means that there will always be energy available, even in inclement weather or due to other problems. From driving your car to taking a shower, and everything in between, the current way most of us operate in the U.S. requires the daily use of regularly available energy.

• Why Would the Use of Alternative Sources of Energy be Beneficial to the Earth and its People?

  The use of alternative sources of energy is beneficial to the Earth and its people because their use has less of a negative impact than the burning of fossil fuels on our planet, and for us Earth dwellers, they provide an avenue to a sustainable future. As non-renewable resources deplete, alternative sources will become more popular and essential to life.