What is renewable energy?

Renewable energy is key to tackling climate change. But what exactly is it?

Renewable energy is energy that is generated from a source that is either limitless — like the sun, wind or water — or one that can be regenerated in a human timescale: such as sustainably managed forests.

Non-renewable energy comes from finite resources — like coal, oil and natural gas. These can only be used until there is no more of them left.

What’s the difference between renewable, low-carbon and carbon neutral energy?

Some renewables can generate power without producing any carbon dioxide (CO2). Solar, wind and hydropower fall into this category.

Other low-carbon energy sources tend to produce some CO2 — but at much lower levels than fossil fuels such as coal.

Bioenergy generated from woody biomass that is sourced from sustainably managed forests is carbon neutral. This is because the forests absorb CO2 while they are growing. This means that there is no increase in the amount of CO2 in the atmosphere.

Of course, getting bioenergy to power stations requires processing and transport. And that means some fossil fuels are used. This means that woody biomass is considered a low-carbon fuel across its whole

Supply chains that bring bioenergy to power stations commonly use some fossil fuels in manufacturing and transportation. Therefore woody biomass is considered a low carbon fuel, when its whole lifecycle is taken into account.

Is nuclear power renewable?

No, nuclear power requires uranium or plutonium to function. There is a finite supply of these, so it cannot be considered as renewable. It is however zero carbon.

Is renewable energy growing?

Yes, it’s growing fast. At the turn of the millennium, the International Energy Agency calculated that renewable energy was responsible for 18% of global electricity generation. In 2019, that figure accounted for 27% of the world’s electrical power. That’s a 50% increase in the space of a single generation.

Why do we need renewable energy to prevent catastrophic climate change?

Emissions of greenhouse gases — including CO2 — into the atmosphere constitute the largest contribution to climate change that is caused by humans.

These gases create a layer that works like a ‘blanket’ surrounding the Earth, making temperatures rise.

Renewable energy can give us the power we need, without producing CO2.

Can renewable energy help remove CO2 from the atmosphere?

We can use bioenergy to remove CO2 at the same time as producing renewable electricity through bioenergy with carbon capture and storage (BECCS).

The way it works is simple. Forests absorb CO2 from the atmosphere as they grow. And when the biomass they produce is used to generate electricity, that the CO2 is captured and stored safely and permanently before it is released into the atmosphere. This helps reduce the total amount of CO2 in the atmosphere.

Renewable energy — the facts:

• There has been a sixfold increase in renewable power in the UK in the last decade.
• Between 2010 and 2019, the cost of producing energy from solar powers was reduced by 82%. At the same time, there was a fall of 40% in the cost of onshore wind and of 29% in the cost of offshore wind.
• Total renewable electricity generation around the world is forecast to hit 3,978 GW by 2025 — almost five times 2000’s total of 849 GW.