What is Renewable Energy?

What is Renewable Energy? 

Renewable energy (also known as clean energy) is energy from natural sources that are replenished quicker than they are used. Almost 30% of the world’s energy use comes from renewable sources [1]. Examples of renewable energy sources include wind power, solar power and biomass. 

Renewable energy is used as an alternative to fossil fuels, which are non-renewable sources of energy. Fossil fuels are used more quickly than they can be replenished, which makes them unsustainable for long-term use. They are also polluting to the environment and produce harmful greenhouse gas emissions. Examples of fossil fuels include coal, oil and gas, which all take hundreds of millions of years to form. 

Diversifying the global energy supply to reduce the reliance on fossil fuels is important. In doing so, we can create more jobs and development in the industry. There are a huge variety of jobs in the renewable energy sector, from engineers to consultants and managers. 

With renewable energy projects growing around the world, renewable energy is becoming cheaper and faster. Let’s take a look at some of the key sources of renewable energy:

Solar Power

In simple terms, solar power is energy taken from the sun and converted into power via solar panels. We can generate both heat and electrical power from the sun using solar. 

Solar is a renewable energy source because the sun’s radiation is infinite – as long as the sun shines, we can harness energy from it. Around 173,000 terawatts (TW) of solar energy radiates to the Earth at any point, which is over 10,000 times the planet’s energy use in the same period. 

Jobs in solar energy are increasing rapidly as the cost of solar power goes down. In Europe alone in 2020, the solar sector created over 350,000 jobs, up from 81,000 in 2016. This number is expected to double to just under 750,000 by 2030 with current targets [2].

Solar power

Wind Power

Wind power is wind energy being converted to electricity through large turbines. Modern wind turbines use the wind to generate over 12% of the world’s electricity, with just over 743GW of wind power capacity worldwide. This helps the world to avoid over 1.1 billion tonnes of CO2 annually – equivalent to the annual carbon emissions of South America [3].

Wind power generation depends on average wind speeds, which vary across the world, but the good news is that the world’s wind energy potential exceeds global electricity production [4]. This means that there is potential for most areas of the planet to produce ample wind power, which is sustainable and clean. 

The wind energy sector employs over 1.1 million people worldwide, and this number is set to increase to over 3.3 million in the next five years [5]. Jobs are available for every stage of the wind power process, from manufacturing and installing turbines, to wind energy consultancy.


Biomass involves using plant and animal-based materials, like wood, crops and household waste, to create heat, electricity or biofuel [6]. We can consider biomass to be a renewable energy source as the organic materials involved remove greenhouse gases from the atmosphere (for example with plants photosynthesising). The energy can be made via processing or direct combustion. 

Biomass, together with technologies that can capture carbon emitted from the combustion process, has an important part to play in meeting global net-zero goals.

In 2021, the bioenergy sector employed over 3.5 million individuals, with this number set to grow in the coming years [7]. 


Wave & Hydro Power

Hydropower works by harnessing energy from the movement of water. A dam or structure creates an elevation difference within the body of water. When the water flows from one area to the next, this movement creates energy which is captured as electricity. 

Hydropower reservoirs are not only used for electricity, they can also be used as irrigation systems and drinking water, making them an extremely useful renewable energy source.

Wave and hydropower is the largest source of renewable energy on the planet, supplying 17% of global electricity generation [8]. According to the latest figures, the hydropower sector employed over 2.2 million people last year. IRENA predicts that this number will grow to 3.7 million by 2050 [9].

Geothermal Power

Geothermal power is energy generated from reservoirs of hot water found below the earth’s surface. The steam from the reservoirs rotates a turbine attached to a generator that produces electricity. 

Electricity generation from geothermal power stations sits at around 13 GW. The global potential for geothermal power is around 70 to 80 GW, meaning plenty of opportunity for growth in this sector [10].

In 2020, there were around 96,000 geothermal energy jobs globally. This number has since increased to over 100,000 and is growing year on year [11].

Geothermal power

“Despite obvious setbacks caused by the COVID-19 pandemic, the Global Renewable Energy Industry grew at the fastest rate since 1999 last year. Worldwide delivery of renewable energy projects, including wind farms and solar projects, grew by 45%, due to the increasing demand for clean energy by governments and corporations. Green Energy already accounts for 1/3 of the total installed electricity capacity in the world. This global upward trend has translated into increasing demand for trained Renewable Energy personnel.”

To start your career in this fast-growing industry, check out our training page.

Renewable Energy Institute - Wave and Hydro Power Training