What is clean energy and how does it work?

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Do you hear a lot of discussions on the topic of electricity generation and struggle to keep up with the conversation? Then you might need a crash course in energy production methods and to learn more about clean energy generation. Good thing you’re here, we have all the information you need to understand this forward-looking concept.

So, what is renewable energy?

Renewable energy is often brought up when we talk about climate change. As you might know, historically, the energy produced using fossil fuels, like coal or gas, was one of the highest sources of greenhouse gas emissions. In fact, it represented 28% of EU greenhouse gas emissions in 2018.

In contrast, there are numerous other ways to produce electricity in less or non-polluting ways. Those are known as renewable or clean energy sources. But what are they exactly?

Renewable energy definition

Renewable energy is defined by the Oxford dictionary as “energy that is obtained from sources that are for all practical purposes inexhaustible, which includes moving water (hydroelectric power, tidal power, and wave power), thermal gradients in ocean water, biomass, geothermal energy, solar energy, and wind energy”. In other words, renewable energy is derived from endless sources of energy that are constantly and naturally replenished. 

Clean electricity production has a wide range of advantages. It is good for climate. Good for the economy. Good for the society at large. And since it is produced from naturally occurring, abundant resources, there is no danger of ever depleting our planet’s precious stocks.

Clean energy, the examples of European Union policies

Nowadays there are numerous sources of clean energy (examples: solar, wind, hydroelectricity). You might have heard about them as they’ve been at the centre of attention and discussions of many entities, both private and public, at local or international level. Governments and international organisations, such as the European Union, have been adopting policies to increase the quantity of clean energy sources, given their clear role in curbing CO2 emissions and fighting climate change.

For instance, the EU has set a goal to reduce its greenhouse gas emissions by a minimum of 55% by the year 2030 compared to 1990. In this endeavour, the shift from fossil to renewable energy sources will be instrumental, with the demand for electricity expected to reach 31% by 2030, and 47% to 60% by 2050. By gradually forgoing fossil fuel, the EU is aiming to achieve carbon. neutrality by 2050.

To reach that target, numerous measures have been put in place by the members of the EU. Results are showing as EU power production from wind and solar energy sources surpassed coal’s for the first time in 2019. A good recap of this transformation can be found in Eurelectric's Power Barometer.

The Russian invasion of Ukraine has added to the urgency to shift away from fossil fuels. Electrification, powered by clean and renewable sources of energy, is the solution to increase Europe’s energy independence, while at the same time, fighting climate change.

Types of renewable energy

Producing and using greener, cleaner electricity is key to ensure that climate change does not spiral out of control. The use of renewable energy sources has proven to be increasingly efficient as investment in technologies have been made. The best-known ones are hydropower, solar energy and wind energy. But do you understand how they work and their particularities?

Solar energy

Earth is provided with an incredible and endless source of energy coming from the sun. Light has great potential to create electricity.

To put it simply, solar electricity is created by converting solar energy into electricity, either by using photovoltaic panels or through solar-thermal turbines. Solar photovoltaic panels are composed of 6 different layers of materials: glass, anti-reflection coating, metal grid, 2 types of silicon and a metal plate. When the sun ray reaches the two different silicon layers, each charged with different electrons (negative and positive), these electrons are forced to move, generating electricity.

On the other hand, solar-thermal turbines make use of the sun’s heat to create steam and – as we saw earlier – activate a turbine creating electricity.

Being an endless resource, sunlight has great potential to power up the world. Although the sun may not shine on a constant basis, it remains one of the most dependable sources of clean energy. Because it is inexhaustible, there is no limit to how much we can draw from its power. As the technology to harness it continues to progress, it will gradually become more efficient and cost-effective. Solar energy is not to be taken lightly as 86% of the world’s population live in 150 countries where sunlight seasonality has very low variation.

Wind energy

Another type of electricity production you have surely heard of is wind power. Windmills make use of an endless resource too: the wind. Equipped with gigantic blades set on a very tall base to take advantage of the stronger wind force found in altitude, the electricity is produced through the kinetic motion of a turbine.

Either on land or offshore, where the wind tends to be stronger, this type of electricity is perfectly renewable.

Despite its weather dependability, experts believe it to be highly efficient and estimate that, properly implemented and with good interconnections between countries as well as proper electricity storage facilities, it could provide one third of the world’s electricity needs by 2050.

Other clean energy sources

While the efficiency of solar and wind electricity is highly recognised and has been strongly encouraged by both local and international organisations, other clean energy sources have emerged and show great potential.


Hydroelectricity is a highly effective source of renewable energy. It can be generated in two different ways, either by using the current of a natural water stream to activate the rotation of a turbine, or by diverging a natural stream and building a dam where the water will be pushed through small holes and rotate a turbine thus creating electricity.

Hydropower currently covers 40% of the EU’s renewable energy sources, and ensures 97% of the Union’s storage capacity. It complements the other renewable energy sources, like wind and solar, by making the energy system more resilient and flexible.


Of course, how could we not mention the incredible tidal power? This constant, predictable and powerful source of energy cannot be neglected as it could bring clean electricity to the masses.


While there is a certain level of controversy surrounding nuclear power, it should be counted among the most  reliable solutions currently at our disposal to produce electricity. Nuclear facilities can generate considerable amounts of electricity without any downtime. In Europe, thanks to strict rules on the management of radioactive waste, nuclear power generation is safe, carbon neutral way to produce electricity.

The future of clean energy 

With great potential to create electricity, clean and renewable energy sources have gained in popularity throughout the years. Still limited by the current energy storage capacities, they will become more and more reliable as technology continues to improve.

What is the issue with non-renewable energy?

Before we can begin to understand why renewable energy is a cornerstone in our fight against global warming, we first need to learn why non-renewable energy is so problematic.

Most ways to produce electricity imply the use of kinetic force (power of motion). So, how does it work?

  1. A fuel is used to heat enough water to produce a high level of steam,
  2. The steam moves a turbine,
  3. A magnet in the turbine will start moving in a generator
  4. The magnet’s rotation will cause a rupture in its magnetic field
  5. Moving the magnetic field will pull and push the electrons and generate an electric current.

Highly efficient, easy to control and constant, non-renewable energy sources have their advantages. But they are far from perfect and their numerous impacts on the environment and climate have been proven over the years. But the most dangerous impact is one that we cannot see: the release of carbon dioxide (CO2).

Carbon dioxide is a gas that, once released, rises into the atmosphere where it stays trapped. Naturally present on Earth, and combined with water steam and other elements, the CO2 produces what is known as a greenhouse effect. This natural phenomenon was historically responsible for maintaining a constant temperature average around the globe. But our modern society and its growing release of CO2 have disrupted its natural functioning, causing the rise of temperature average, leading to other environmental problems such as the ice cap melt, the rise of water levels….

To add to that, non-renewable resources have another disadvantage right there in their name: they are non-renewable, meaning that those resources are slowly being used away and cannot be produced again – or at least not in a few lifetimes.

So how can we keep our modern way of living and reduce our impact on the environment?

Can clean energy replace fossil fuels?

As clean energy becomes cheaper and more reliable thanks to new technologies, we will be able to replace non-renewable energy such as fossil fuels with cleaner, renewable one. The European Union’s target, for example, is to increase the shares of clean energy and become carbon neutral by 2050.

How can clean energy be used?

Clean energy can be used the exact same way as non-renewable energy. Electricity travels through the same cables no matter where it comes from and has the same ability to power electrical devices.

Can renewable energy reduce global warming?

By avoiding the release of CO2 through the combustion of fossil fuel, renewable energy could help reduce the greenhouse effect, thus diminishing global warming.

Is nuclear energy renewable?

The answer to this is no. But nuclear energy in itself is a clean, carbon-free source of energy. However, the resources needed to generate electricity are not renewable. In fact, while the uranium used to create the nuclear fission necessary to generate electricity is relatively easy to find, the , an isotope called plutonium 239, is much harder to come by.

Nuclear energy doesn’t release carbon dioxide (CO2) and hence it is not contributing to the greenhouse effect. As hydropower, it plays an important role in ensuring a resilient, reliable and flexible energy system.

Is solar energy renewable?

Yes, solar energy is an inextinguishable source of energy, making it a renewable source of energy.

Is wind energy renewable?

Wind is an endless resource, renewed day after day, making it a renewable energy source.

Is wave energy renewable?

Yes, wave energy is renewable as the tides are a constant cycle, always renewing them.

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