Types of renewable energy

What is renewable energy and how does it work?

Renewable energy is a type of energy that comes from renewable resources.

Renewable energy goes by many different names – green energy, sustainable energy, alternative energy and clean energy.

What are the different types of renewable energy sources?

There are five major renewable energy sources:

• Wind energy
• Solar energy
• Hydro energy
• Biomass energy
• Geothermal energy

What are renewable resources?

A renewable energy resource is energy that is sustainable - something that can’t run out, like the sun, wind and water.

What is the difference between renewable and non-renewable resources?

A non-renewable resource for example would be fossil fuels. These take millions of years to develop, and they’re a limited resource because we’re using them much faster than they’re being produced.

Burning fossil fuels produces the greenhouse gas, carbon dioxide (CO2). So we’re increasingly turning to renewable energy sources to generate more environmentally-friendly power.

We source more renewable energy than other suppliers

Find out which energy sources we use to produce our energy – our fuel mix - and where the UK’s energy comes from.

We’re helping the UK hit zero carbon emissions by 2050 with home-grown, greener technologies key to supporting the transition away from fossil fuels.

Check out Our Journey to Net Zero for more information.

What renewable energy sources do we use in Great Britain?

There are five major renewable energy sources, all of which are used to a lesser or greater extent to help power our homes and businesses across Britain and the UK. 

Zero-carbon power sources in Britain’s electricity mix outperformed traditional fossil fuel generation in 2023 by providing 51% of the electricity used, compared to 32% from gas and 1% from coal.¹

Below we explain more about each of the renewable energy sources.

Wind power

Wind is a plentiful source of clean energy and wind farms are an increasingly familiar sight in the UK with wind power making an increasing contribution to the National Grid. To harness electricity from wind energy – on land or at sea - turbines are used to drive generators which then feed electricity into the National Grid. 

Offshore and onshore wind farms

The UK is a world leader in offshore wind farms and boasts the world's largest offshore wind farm in the North Sea. Offshore and onshore wind power accounted for 29.4% of total UK electricity generation in 20231. This is expected to grow with investment and is important to the UK reaching net zero greenhouse gas emissions by 2050.

Wind power – advantages and disadvantages

Offshore wind turbines rotate at faster, more consistent speeds so they can produce significantly more electricity than turbines on land.

High capacity, high cost

The downside is they’re more expensive to develop and to maintain. Onshore wind turbines are cheaper to build and to install, but they’re often unpopular with local communities.

Solar power

It might seem like sunny days are in short supply, but the UK gets nearly 5% of its electricity from solar energy¹. After wind and bioenergy, solar power is the third most generated renewable source in the UK.

How sunlight creates electricity

Solar technologies convert sunlight into electrical energy that can be used to generate electricity or be stored in batteries or thermal storage.

A solar PV (photovoltaic) panel consists of many cells made from layers of semi-conducting material, most commonly silicon. When light shines on this material, a flow of electricity is created.

Solar power – advantages and disadvantages

Over the past decade solar energy has emerged as a viable, mainstream solution to climate change. However, the amount of solar energy we can use varies according to the time of day, time of year and geographical location. In the UK, solar energy is an increasingly popular way to supplement energy usage. PV installations rose by nearly 30% in 2023 to just under 1.42 million – more than 5% of all UK households². In addition, there are currently around 1,000 solar farms in the UK providing clean energy to the grid.

Reduce your bills and carbon footprint with solar panels

If you’re a homeowner with solar panels, you’re already enjoying the benefit of lower energy bills by generating your own. Better still, you can earn money when you export any excess electricity back to the grid through the Smart Export Guarantee.

Power your home with solar energy – our solar solutions.

What is hydro energy?

Hydro energy or hydroelectric energy is a form of renewable energy that uses the power of moving water to generate electricity by using a dam or diversion structure to alter the natural flow. It’s one of the oldest sources of renewable energy dating back thousands of years. Hydro energy accounted for around 1.8% of the UK’s total electricity generation in 2023, mostly from large scale schemes in the Scottish Highlands 1.

Advantages and disadvantages of hydro energy

With its mountainous terrain and high reservoirs, the UK is a great place for building hydroelectric power stations and it’s a readily available domestic source of energy, but future development is likely to be limited by concerns over its environmental impact on the land and wildlife. Plus, the cost of large-scale construction is prohibitive.

What is tidal energy?

Tidal energy is another form of hydro energy that uses tidal currents to drive turbine generators to produce electricity. Tidal flow, unlike other hydro energy sources, isn’t constant but it is plentiful and highly predictable. The main barrier to investment in tidal power is high construction costs when compared to wind and solar.

Biomass energy

Biomass energy is generated from burning wood, plants and other organic matter like manure or household waste to produce electricity. It releases carbon dioxide (Co2) when burned, but substantially less than fossil fuels.

Is biomass renewable?

We consider biomass a renewable energy source, if the plants or other organic materials being burned come from a sustainable source and are replaced.

There are currently around 78 biomass power stations operating in the UK. Biomass only contributed around 5% of Britain's electricity mix in 2023. 1 This is expected to rise by as much as three times that in the coming years and will be an important renewable resource for the UK to help reach its Net Zero ambitions.

Biomass energy – advantages and disadvantages

Biomass is considered a renewable source because it’s generated from plant and organic material that can re-grow in a relatively short time – compared to the millions of years it takes to form coal and natural gas.

Climate change concerns

Burning biomass produces greenhouses gas, so there are questions about its sustainability.

Some say that burning wood is carbon-neutral. That’s because trees take in carbon dioxide when they’re alive, and release it back into the atmosphere when they die.

Could biomass be carbon-neutral?

Whether they’re burned or decompose naturally, the amount of CO₂ released is about the same. So in theory, if trees are replanted as quickly as they’re harvested, the new trees will absorb and store the same amount of CO₂ that burning wood produces. Which makes the whole process carbon neutral.

Other renewables are greener

Biomass energy is certainly ‘greener’ than fossil fuels – where none of the released carbon is offset. But the greenhouse gas savings are much less than other forms of renewable energy like wind or wave power, which create almost no CO₂ emissions.

What is geothermal energy and how is it generated?

Geothermal energy is a renewable energy source extracted as heat from the earth’s crust which comes from the slow decay of radioactive particles, a process that happens in all rocks. It’s a reliable and constant source of low-carbon, renewable heat that is not dependent on weather conditions.

People use geothermal heat for bathing, for heating buildings, and for generating electricity through for example ground source heat pumps (GSHP).

Advantages and disadvantages of geothermal energy

Geothermal energy is a reliable source of power with a small land footprint and can be used for large and small-scale installations. However, it’s location dependent – geothermal power plants can only be built in certain locations - set up costs are high and can lead to surface instability.

While we use very little geothermal energy in the UK, the industry is growing worldwide and it’s a significant source of renewable energy for countries like Iceland, New Zealand and Kenya. 

British Gas and renewable energy

We’re at the forefront of cleaner, greener energy. For years we’ve been investing in the development of offshore wind farms. And in ‘green’ gas – biomethane produced from biomass.

We’re greener than you may think

As a uniquely integrated energy and services company, we’re committed to helping decarbonise the UK’s electricity system and reaching net zero.

Learn more about Our Journey to Net Zero.

And we're rewarding customers for being greener too

If your electricity is with British Gas and you have a smart meter, join the hundreds of thousands of customers who’ve signed up to our PeakSave scheme.

PeakSavers can earn credit towards their bills by helping to the grid to better balance demand for electricity when it’s particularly high, or low.

When demand for electricity is at its highest, it’s often necessary to generate more electricity by burning fossil fuels. And when its low, a greater proportion of energy is more likely to come from renewable sources.

Already generate your own renewable energy?

Take a look at our smart export guarantee scheme and get paid for excess electricity you export to the grid.