Everything You Need to Know About Alternative Energy Sources (Ultimate Guide)

The different types of alternative energy sources and their advantages and challenges

Reviewed by
Kunsulu Nurekeyeva

The fast-paced, continuously developing and always changing world we live in has higher and higher energy demands. Given the catastrophic effect that our reliance on fossil fuels has on the very environment we live in, a quest for alternative energy sources has been the top priority on the agenda of the century. We will go through the most developed energy sources one by one, highlighting the operating principles and advantages and disadvantages of each.

Natural gas

Natural gas is a fossil fuel that has been used as a source of energy for heating, cooking, electricity generation and vehicle fuel for hundreds of years. It is a non-renewable source of energy, which is formed by layers and layers of decomposing animal and plant matter being exposed to the heat and pressure under the surface of the Earth over billions of years. Compared with coal and oil, it’s a relatively cleaner alternative. The advantages of using natural gas include its abundance and wide use worldwide, existing technology infrastructure and end use appliances. It can also be used as a chemical feedstock to produce plastics, chemicals, and fertilizers. Moreover, the natural gas industry is a big employer. On the other hand, natural gas is harmful for the environment, as it emits carbon dioxide, and is mostly made up of methane, which is a potent greenhouse gas. There are also substantial environmental concerns associated with fracking, which is a drilling technology, used for extracting natural gas. Fracking requires large amounts of water, and there are concerns regarding the chemicals used during fracking, as they contribute to groundwater pollution and contamination. Natural gas is also difficult to store and and transport, as it needs to be stored and distributed under high pressure, and requires extensive pipelines in order to be disseminated over land.

Hydrogen gas

Contrary to natural gas, hydrogen is a completely clean fuel, with water and warm air being the by-products of energy generation. Hydrogen is the most abundant element on Earth but it doesn’t occur naturally on its own, so it has to be extracted from compounds that contain it, such as hydrocarbons and water. There are many advantages to hydrogen gas: it is a renewable, abundant, sustainable, and clean source of energy. It doesn’t produce any harmful emissions and it is non-toxic, which means it doesn’t harm the environment and has no effect on human health. It is also an extremely efficient fuel, which unravels a huge potential for hydrogen gas use in the automotive industry. Nevertheless, the extortionate costs and emissions associated with hydrogen extraction remain the main barrier for hydrogen energy use and implementation. Hydrogen gas can be extracted from water via electrolysis, which involves high energy expenditure, or steam reforming, which is accompanied by greenhouse gases emissions. In addition to the extraction expenditures, building the infrastructure will also add to the bill significantly. Moreover, it is extremely tricky to transport or store hydrogen, as it has very low density, so high pressure systems needed. Hydrogen is also extremely flammable and explosive.

Wind power

Harvesting power from wind is a popular sustainable and renewable energy source. Wind supplies mechanical power to wind turbines, which rotate and send this power to electric generators. When compared to other renewable energy sources, wind energy provides a more efficient power source than solar energy. Compared to hydroelectric power, where damming water to build reservoirs leads to destructive land use, as the surrounding ecosystems damage and valleys flood, wind energy preserves land. Wind energy is a very promising energy source with great potential and many advantages, however, there are definitely noteworthy drawbacks that need to be addressed. Wind is a clean, renewable and sustainable energy source, as we will never deplete our wind sources and harvesting energy from wind is pollution free. Wind energy is space-economical, as wind farms can be installed on already existing farms with minimal effect on the surrounding environment and livestock, or in rural areas. Wind turbines and farms also don’t require water for cooling. Even though there are greenhouse gas emissions associated with manufacturing and putting in wind turbines, once installed, they do not emit any harmful gases during operation. The costs of operating are also pretty low and stable. Switching to wind energy contributes to energy independence and jobs creation as well. Nevertheless, wind is an intermittent energy source and additional energy storage devices are required to compensate for downtime. The blades of wind turbines rotating at high speed also pose a threat to wildlife and even ground-level fauna can be affected by noise pollution. Extensive construction is required to build wind farms, together with high upfront costs. In addition, noise and visual pollution are also wind energy pros to be considered.

Solar power

Solar energy has gained a lot of traction in the past few decades and has become a very popular energy technology within residential, commercial, industrial, and agricultural sectors. Solar energy offers a renewable and sustainable solution to our ever-growing energy needs. It is an abundant resource and the sun energy can be harvested from anywhere in the world, in any weather, as long as there is a little sunlight coming through. For homeowners, going solar allows to make significant saving on the monthly electricity bills, with return on investment. Solar panels require very little maintenance and have a long lifetime. On the other hand, as many other energy sources, solar energy requires high upfront costs. Similarly to wind energy, solar power has an intermittent nature due to the inconsistency of sun coverage throughout a day or at a certain geographical location. Not every roof fits for a solar panel installation, and once installed, those panels are hard and pricey to move. Manufacturing solar panels has a negative environmental impact, including carbon and greenhouse gases production, reliance on fossil fuels, plastic waste generation, and use of toxic materials.

Geothermal energy

Geothermal energy is a sustainable and renewable energy source in form of the heat, that emerges from the sub-surface of the Earth. This thermal energy originates from the radioactive decay of matter. The geothermal power is produced from utilizing steam and hot water from underground and feeding it to turbines, which are in turn connected to electricity generators. As with any other alternative energy source, there is a good amount of pros and cons that need to be considered, when it comes to this fairly unexploited energy source. On a positive side, geothermal energy is environmentally friendly and has a low carbon footprint. There is some pollution that gets released during geothermal energy harvesting, but it is relatively insignificant, when compared to fossil fuels. Geothermal energy is renewable and sustainable, as the hot reservoirs are naturally replenished. When compared to wind or solar energy, geothermal energy is more reliable, as it doesn’t depend on weather conditions or fluctuate significantly. The largest disadvantage of geothermal energy, however, is that it is location specific, and lion share of geothermal energy is limited to countries, such as US, Iceland, Kenya and Indonesia. The upfront costs for building a geothermal plant are also quite high. Furthermore, even though there is minimal carbon emissions, other harmful gases, such as sulfur dioxide and hydrogen sulphide can be released. Geothermal energy harvesting also runs the risk of triggering earthquakes.

Hydroelectric energy

Hydroelectric power is one of the oldest and cheapest ways to produce energy, and is also the most commonly used renewable energy source. According to a 2020 Hydropower Status Report, hydroelectricity provided us a record 4.306 terawatt hours, representing about 17% of total electricity production. Hydroelectric energy is based on a principle of harnessing power from water in motion, for example, from a waterfall or a fast-moving river. It has many attractive qualities: hydropower is completely renewable and emission free, it is the most reliable source of renewable energy available, and provides energy and price stability. Hydropower plants can also be adjusted to meet the energy needs on a given day, producing more or less energy on demand. Hydroelectric energy production also contributes to flood control. Hydropower can be used in combination with other renewable sources, such as wind and solar energy, as a back-up during down times, due to its flexibility and energy storage capacity. The disadvantages of hydropower are definitely worth-mentioning, as they entail significant environmental concerns. in order to create a hydro plant, there needs to be a dam, which prevents fish from feeding, which in turn affects other animals, that rely on fish. Due to transportation and logistics challenges, hydropower plants can be incredibly expensive to build. They also can lead to droughts and ecosystem damage in the areas, where they are installed. It has also been shown that over the course of a lifetime of a hydropower plant, plants at the bottom of reservoir rot and decompose, releasing vast amounts of carbon dioxide and methane, contributing to pollution.

Biomass energy

Biomass is a renewable source of energy, which is derived form burning animal and plant waste. It is a great and sustainable way of recycling waste into energy. Biomass fuels can be made up of scrap lumber, forest debris, manure, certain crops and other waste. There are many advantages to using biomass energy. Biomass has wide availability and unlimited supply, since waste is constantly being produced. Biomass technology is also very cheap, without the need for heavy machinery or advanced materials. Another big advantage of using biomass energy is that it contributes greatly to better waste management, which is a growing problem globally. There are few shortcoming as well, though. First off, biomass is less energy efficient than fossil fuels. Just like fossil fuels, it releases carbon dioxide upon combustion. Whether there is carbon balancing due to the fact that trees and plants absorb carbon dioxide throughout their lifetime is questionable. Burning biomass releases methane gas, which is damaging to the environment. Biomass plants also occupy a lot of space, and seasonality of biomass supply can be problematic as well.

Nuclear power

Nuclear power relies on nuclear reactions to produce electricity. Enriched uranium is used as a fuel, and atoms are split in a reactor, which releases energy, that heats water and transforms it into steam, which then turns turbines that generate electricity. Nuclear power is one of the most debated and heavily politicized alternative energy sources. Let’s take a look at the advantages. Nuclear power does not produce greenhouse gases, such as methane or carbon dioxide. Nuclear power is exceptionally efficient, stable and reliable. Very little of inexpensive processed uranium is needed to produce vast amounts of electricity, together with operating costs being low as well. Nuclear power also creates jobs and drives scientific and technological progress. On the other side of the coin, safety is a huge concern, with Chernobyl and Fukushima accidents tragic effects spanning generations. There are a lot of environmental issues with mining, processing and transporting uranium. In addition, the waste from a nuclear power plant can not be handled in a traditional way, as it is radioactive and dangerous. Moreover, initial costs for building a nuclear plant are astronomical, as one would imagine. Nuclear energy is not renewable, as the resources of uranium are finite. Given the fact that nuclear energy can be used to make nuclear weapons and the existing geopolitical tensions, associated with the uranium resources being limited to a few countries, nuclear power is a very tricky subject.


There are many alternative energy sources available to us, ranging from harvesting energy from natural occurring phenomena, such as wind, sun and water, to producing power from waste and uranium chain reactions. While some energy sources are location-specific, such as geothermal and hydroelectric power, other alternative energy sources, such as solar, wind and biomass can be accessed anywhere on our planet. Many of these energy solutions have a lot to offer in terms of decreasing our reliance on fossil fuels and switching to a renewable, sustainable and clean energy. However, there are usually high initial costs associated, along with other environmental or societal challenges.


Why do we need alternative energy sources?

We need to decrease our reliance on fossil fuels, that are harmful to the environment and lead to climate change. In order to do so, a shift to alternative energy sources, that are clean, renewable, and sustainable is necessary.

What kind of alternative energy sources are out there?

There are many alternative energy sources that exist, including wind, solar, hydroelectric, biomass, nuclear, geothermal, wave, tidal energies and natural and hydrogen gases.

What renewable energy is the most widely used?

Hydroelectric power is the most commonly used renewable energy source. According to a 2020 Hydropower Status Report, hydroelectricity provided us a record 4.306 terawatt hours, representing about 17% of total electricity production.

Why are we still using fossil fuels?

They are efficient, convenient and familiar technology. The calamitous effect that it has on our planet and our lives is not immediate, even though indisputable.

Kunsulu Nurekeyeva

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Author Bio

Kunsulu Nurekeyeva's photo

Kunsulu Nurekeyeva

Kunsulu Nurekeyeva is a writer and an academic researcher with expertise in Chemistry and Sustainability. She holds a Bachelor’s in Liberal Arts and Sciences from Maastricht University and an Erasmus Mundus Joint Master’s Degree in Energy Storage and Conversion.

Her multidisciplinary research background and rich academic experience translate to a unique perspective on renewable energy and solutions.

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