I think the cost of energy will come down when we make this transition to renewable energy.”

Al Gore, Politician

What are Alternative Energies?

Alternative energies can be defined as power that can be generated without the use of fossil fuels.

In our current global state of the world, the advancement of alternative energies is crucial in order to mitigate global warming and to save the human species from vast destructive events in the future.

While these alternative energies have significant upsides compared to conventional fossil fuels, they also have some important weaknesses.

In this article, the most important alternative energy opportunities and their respective strengths and weaknesses are examined.

Why are Alternative Energy Sources important?

Currently, as at 2020, the biggest sources for worldwide energy production are oil, coal and gas.

The burning of fossil fuels implies the emission of harmful greenhouse gases, which in turn contributes to climate change and its severe adverse consequences.

Therefore, switching from conventional to alternative energy sources is crucial to advance as mankind and to secure a livable future for the next generations.

What is the Difference between Alternative Energies and Renewable Energies?

Although alternative energies and renewable energies are often mentioned in the same context, they are actually not the same.

While renewable energies fully replenish themselves naturally without the interference of humanity, alternative energies might replenish themselves but it is not a necessary requirement.

Thus, alternative energies are focused on the reduction of carbon dioxide emissions as main goal in order to mitigate global warming.

For instance, while nuclear power can be regarded as alternative energy since it does not produce much carbon dioxide, it cannot be considered a renewable energy source since it does not replenish itself and therefore can be depleted over time.

In the following, the most important alternative energy sources are examined.

12 most promising Alternative Energy Sources

  1. Nuclear power
  2. Wind energy
  3. Solar power
  4. Hydroelectricity
  5. Biofuels
  6. Biomass power
  7. Natural gas
  8. Geothermal energy
  9. Ocean energy
  10. Wave & tidal energy
  11. Hydrogen power
  12. Future power sources

Nuclear power

Nuclear power is the power that is generated through the use of radioactive material.

By using nuclear material, water is heated which in turn is then usually used to propel steam turbines in order to produce energy.

The earliest research on nuclear power had been carried out by the physicist Ernest Rutherford in 1932.

The first nuclear reactor was finished in 1942.

However, it was not only used for energy purposes but also for the development of nuclear weapons.

Although nuclear energy is regarded as quite efficient energy source, it is also one of the most dangerous in terms of accidents.

Nuclear accidents can have tremendous adverse effects and can pollute large areas of land.

Prominent examples for this are the accidents of Chernobyl or Fukushima.

There is also a problem regarding radioactive energy when it comes to the disposal and processing of nuclear waste.

In our current times, it is quite common that nuclear waste is stored in mines or other places deep inside the ground where it is meant to decay.

However, it is hard to assess the long-term consequences of this disposal behavior since our groundwater as well as the soil may be contaminated in the long run.

Advantages of nuclear energy:

  • Relatively cheap
  • Quite efficient
  • Extensive research has been done to optimize processes
  • Relatively clean in terms of greenhouse gas emissions

Downsides to nuclear power:

  • Non-renewable
  • Dangerous in terms of accidents
  • Unclear long-term consequences of radioactive waste

Wind energy

Wind energy has become quite popular over the past few decades.

It can be regarded as renewable energy since wind cannot be depleted.

Through mechanical power, wind is used to propel wind turbines which turn electric generators in order to produce energy.

The first windmill for electric power generation was built in 1887 in Glasgow, Scotland.

Since then, extensive research has been done on the topic of wind energy, making it much more efficient over time.

Windmills are regarded as a main pillar of energy production in the future since they have not too many long-term issues and can produce significant amounts of clean energy.

Although there are many upsides to wind energy since it can be regarded as a renewable energy source, there are also some issues related to it.

Some people complain that windmills lead to visual pollution in the environment.

This makes it hard to expand the use of wind energy since many people do not agree to build windmills in their near surroundings and therefore try to prevent building these windmills.

Upsides of wind energy:

  • Renewable energy
  • Easy to operate
  • No great dangers for accidents
  • Relatively quiet
  • Low levels of emissions

Disadvantages of wind power:

  • Visual pollution
  • Relies on wind in order to work

Solar power

Solar power is a quite interesting source of energy since it is considered a renewable energy and also will become even stronger in the future due to climate change and the ozone depletion issue.

Solar power can be regarded as the conversion of sunlight into electricity that can be in turn used for several purposes.

For the production of solar power, photovoltaic systems are used to store sun energy and convert it into electricity.

The first conventional solar power plants have been invented around 1980.

Since then, the technology behind solar energy has been developed further and be made more efficient.

Solar energy can be regarded as one of the most promising energy sources when it comes to future worldwide energy supply.

Although solar power is quite important with regard to the transition to renewable energies, it also has some disadvantages.

The solar panels have to be initially produced which may also imply some level of pollution regarding this production process.

Moreover, solar panels can be quite expensive.

Thus, many private persons may refrain from buying these panels.

Since sunlight is crucial for the production of solar energy, regions with low levels of sunlight will not be able to operate solar panel modules in an efficient manner.

Advantages of solar power:

  • Renewable energy sources
  • Important for long-term energy supply
  • Quite efficient, especially in sunny regions

Disadvantages of solar power:

  • High upfront costs for private households
  • Dependent on the weather
  • Some pollution through the production of solar panels


Hydroelectric power is a quite common source of power that uses the power of water to create electricity.

It is one of the most important electricity sources worldwide when it comes to renewable energies.

Hydroelectric power will continue to be one of the most important energy sources in the future.

There are several different types of hydroelectric power, depending on the geographic features of a region.

The biggest hydroelectric power facilities are able to produce significantly more energy than the currently largest nuclear power plants.

The biggest hydroelectric power facilities in the world are the Three Gorges Dam in China, the Itaipu Dam in Brazil and Paraguay and the Xiluodu Dam in China.

Hydroelectric power has a variety of advantages.

It is quite flexible and power can be produced at a relatively low cost.

It can also significantly reduce carbon dioxide emissions compared to conventional energy sources.

However, hydroelectric power also has some downsides.

The building of large dams to install hydroelectric power plants can harm the local flora and fauna and may also lead to significant visual pollution.

It may also lead to water shortages for nearby regions since for energy production, large amounts of water have to be stored.

If these dams break, there is also a big danger for flooding of large areas of land.

There may also be some methane emissions related to hydroelectric energy from the reservoirs that are used for energy production.

Moreover, for the construction of big hydroelectric power facilities, many people living in nearby areas may have to be relocated and may therefore lose their homes.

Advantages of hydropower:

  • Relatively low cost for energy production
  • Quite flexible
  • Low level of greenhouse gas emissions
  • Important in the transition process from conventional to alternative energies

Downsides of hydroelectricity:

  • Water loss due to evaporation
  • Methane emissions
  • Relocation of the local population
  • Visual pollution
  • Potential accidents may be quite deadly


Biofuels are produced by using biomass of many different sorts.

There are many different types of biofuels.

First-generation biofuels are generated by using food crops that are intentionally grown for the sole purpose of energy production.

These include sugar or vegetable oil which are then processed into ethanol or biodiesel.

Second-generation biofuels include agricultural residues or plant material waste that can be used for the production of energy.

Further generations try to be even less material consuming, using algae or even abstract from the destruction of biomass and rather strive for total carbon neutrality.

Depending on the generation of biofuels, they can be an effective measure for the transition process from conventional to alternative and renewable energies.

First-generation biofuels are the most ineffective since they consume large amounts of biomass which could be used to provide food for people otherwise.

Thus, this generation of biofuels had been banned by the EU in 2020.

The future goal is to transit to sustainable biofuels which may be also greenhouse gas neutral in the long run.

Upsides of biofuels:

  • Good supporting measure in the energy transition process
  • Greenhouse gas neutral if advanced enough generations are used
  • Currently significant share in alternative worldwide energy mix

Downsides of biofuels:

  • First-generation biofuels can be regarded as inefficient use of resources
  • Currently not greenhouse gas neutral on a broad scale

Biomass power

Biomass energy can be produced from burning wood or other plant material.

Compared to biofuels, biomass consists of all non-fossil organic materials that contain intrinsic chemical energy.

However, since biomass is often used for the production of biofuels, both of them have similar strengths and weaknesses as a source of energy.

Strengths of biomass:

  • Valid supplementary energy source in the energy transition process
  • Carbon dioxide neutral if advanced enough methods are used
  • Currently big share in alternative worldwide energy mix

Weaknesses of biomass:

  • Currently mainly not greenhouse gas neutral
  • Often inefficient use of resources

Natural gas

Natural gas, sometimes also referred to as fossil gas, is a gas mixture that naturally occurs in nature.

It consists of large amounts of methane and may also include some other greenhouse gases like carbon dioxide.

It is naturally produced when plant material or other organic material is decomposed and exposed to high levels of pressure and heat under the earth’s surface.

Although natural gas can be considered as an alternative source of energy, it is non-renewable since it usually takes millions of years to form.

Natural gas is used on several occasions in our daily life, including cooking and heating purposes.

It is also used for electricity generation.

Even though natural gas is considered to be the less damaging fossil fuel regarding the emission of carbon dioxide, it still leads to the emission of significant amounts of greenhouse gases.

Therefore, natural gas can be regarded as a suitable substitute for other fossil fuels in the short term, but will not be a suitable energy source in the long run compared to other alternative energies.

Advantages of natural gas:

  • Easy to process
  • Mature technology
  • Relatively safe

Disadvantages of natural gas:

  • Non-renewable energy source
  • Significant greenhouse gas emissions
  • Not suitable as long-term solution

Geothermal energy

Geothermal energy is a quite common form of electricity generation.

It uses the thermal energy that is stored in the earth.

The use of geothermal energy had been quite popular throughout the history of mankind.

Geothermal energy in the form of hot springs has been used millions of years ago.

For commercial heating purposes, the first geothermic district heating system had been used in Boise in America in 1892.

Over the years, the technology behind geothermal energy has been improved and developed further on a steady basis.

Since geothermal energy does not require the use of fuel, it can be considered as quite clean since it only emits low amounts of greenhouse gases.

It is also a renewable energy source that cannot be depleted and therefore might be a promising alternative industry source regarding the energy transition process.

However, it also has some downsides.

The costs of setting up geothermal facilities can be enormous.

Therefore, energy from these facilities can be quite costly.

Moreover, for the construction of geothermal power plants, large areas of land have to be used and local flora and fauna may be harmed.

In addition, in the energy production process, significant amounts of heavy metals can reach the surface, which in turn may lead to enormous soil pollution with harmful substances.

Advantages of geothermal energy:

  • Renewable energy
  • Doesn’t depend on weather conditions
  • Low levels of greenhouse gas emissions

Disadvantages of geothermal power:

  • Relatively high costs
  • Destruction of local flora and fauna
  • Contamination of local environment with heavy metals like mercury or arsenic

Ocean energy

Ocean energy, often also referred to as marine power or hydrokinetic energy, can be defined as energy that can be produced with the help of tides and ocean temperature differences.

Although there is a huge potential of ocean energy due to the vast amounts of energy that are stored in the water of our oceans, it is still not a main source of energy production since our technologies are not ready yet to use it in an efficient manner.

Ocean energy can be regarded as renewable energy source since there is no reason why ocean energy should vanish from our planet.

Ocean energy is converted into power that can be used by humans mainly in the form of turbines that are placed in the water and which in turn produce energy.

The share of ocean energy in the total alternative energy mix is currently quite low.

Plenty of research has to be done if we want to bring ocean energy to a state where it is able to produce enough energy to become an important energy source in the future.

Advantages of ocean energy:

  • Renewable energy
  • Low level of carbon dioxide emissions
  • Vast potential due to enormous amounts of energy stored in the oceans

Disadvantages of ocean energy:

  • Currently rather small source of energy
  • Likely not scalable enough to be a reliable energy source in the future

Wave & tidal energy

Wave power can be defined as the capture of the energy of wind waves in order to produce energy for industrial purposes.

Wave energy is not well-known to the public and it is a rather small energy source, at least at our current state of technology.

The first commercial wave power facility had been installed in 2000 at the coast of Scotland.

Although some research is done on wave energy, scientists estimate that the share of wave energy compared to other alternative energies will be quite low since it is not a technology that will be able to offer enough advantages.

Wave energy is also dependent on geographic conditions.

There may also be adverse impacts on marine life through noise pollution and other forms of contamination related to the production of wave energy.

Moreover, local fishermen may be displaced since fishes may relocate due to the facilities that are necessary for wave energy production.

Thus, these fishermen may lose their livelihood due to the expansion of wave energy.

Advantages of wave energy:

  • Renewable energy
  • Relatively small adverse environmental effect
  • Low levels of carbon dioxide emissions

Disadvantages of wave energy:

  • Not sophisticated enough yet to produce large amounts of energy
  • Adverse effects on marine life
  • Destruction of livelihood for local fishermen
  • Potential for energy production quite low compared to other alternative energies

Hydrogen power

Hydrogen power, sometimes also referred to as hydrogen fuel, is often used in internal combustion engines or fuel cells.

Hydrogen power has a huge potential to become a quite important energy source in the future since it is regarded as a zero-emission fuel and can therefore regarded to be the cleanest and the most sustainable way to produce energy.

Hydrogen fuel can be produced by the electrolysis of water or also from methane.

However, hydrogen energy could potentially be won out of water if we are able to develop advanced enough technology to do so efficiently.

Imagine a world where all of our energy could be produced just out of water without any emissions.

Wouldn’t that be great?!

Unfortunately, it will take plenty of time to be able to develop technologies to be able to do so.

However, in a few decades, hydrogen power may become the main source to meet our energy demands.

Upsides of hydrogen fuels:

  • Renewable energy
  • Energy production with zero-emissions theoretically possible
  • Promising technology to provide humanity with clean energy in the medium and long term

Disadvantages of hydrogen power:

  • Not yet fully explored yet
  • Currently not sophisticated enough to provide large amounts of energy

Future power sources

Apart from the energy sources mentioned before, there might be some sources of energy that have not been explored yet.

For instance, maybe humanity will find an even better energy source due to sophisticated research in the near future, which may become the gold standard for future energy production in the next century.

Since the progress in technology is such big, it is hard to imagine how our energy supply will look like in the future.

Distribution and Share of Energy Sources worldwide

Around 17% of all energy that is produced worldwide came from renewable energies in 2019.

Fossil fuels still made up the huge majority of energy supply worldwide.

The distribution and the shares of the respective energies are displayed below.

Source: Data from the Statistical Review of World Energy 2019

Source: Data from the Statistical Review of World Energy 2019

How could a Future Energy Mix look like?

It is quite hard to predict how the future energy mix could look like since technological advancement is such rapid.

However, below, I tried to picture what the future energy mix could look like in 2050 to give an impression on the changes many scientists expect.

Source: Own estimation based on past trends

Upfront Research Costs vs. Social Long-Term Benefits

In the discussion of the transition to alternative energy sources, it is crucial to evaluate the upfront research and development costs against the long-term benefits of these energy sources.

In the following, a graphical illustration is given in this regard.

From this illustration, you can see that solar energy and hydrogen power may be the most promising technologies in the medium and long run while natural gas as an alternative energy source will lose its importance since it is a source of greenhouse gas emission.


The transition from fossil fuels to alternative energies is crucial in order to ensure a livable future for the next generations.

We will only be able to slow down global warming if we stop using energy sources that imply the emission of large amounts of greenhouse gases and instead switch to green energies like solar power.

In the long run, hydrogen power may be the most promising energy source since it implies almost zero emissions and is fully renewable.





About the author

My name is Andreas and my mission is to educate people of all ages about our environmental problems and how everyone can make a contribution to mitigate these issues.

As I went to university and got my Master’s degree in Economics, I did plenty of research in the field of Development Economics.

After finishing university, I traveled around the world. From this time on, I wanted to make a contribution to ensure a livable future for the next generations in every part of our beautiful planet.

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