Renewable energy: Types, forms and sources

18 May 2020 | OVO Energy

What is renewable energy?

A renewable energy source means energy that is generated from sustainable, 100% renewable sources like wind, sun, and water. 

It’s called renewable, or sometimes infinite energy because it can renew itself quickly - time and time again.

We're focusing on renewable electricity in this blog. And, as the cleaner, greener way to power our homes, it's got a big part to play in building a sustainable energy system of the future.

And the opposite of renewable energy is...

You've got it: dirty fossil fuels. These are coal, oil and gas, which take hundreds of millions of years to form (they’re fossils, as you might have guessed). They can never be replaced, before we use them all up. So burning them is completely unsustainable. Plus, they release carbon emissions when they’re burned, making the climate crisis worse. Yikes.

Renewable energy sources

There are many great sources of renewable energy. And, these days, lots more companies (like us) are embracing the tech that’s needed to make renewables popular. The good news: it’s predicted that renewables will power 40% of the world’s demand by 2040.

At OVO, renewable electricity comes from a range of green sources, including:

  1. Geothermal energy.
  2. Hydroelectric power.
  3. Solar power.
  4. Wind power.

To find out 20 fascinating renewable energy facts to inspire you, just read our blog post! 

4 popular types of renewable energy sources

Solar energy 

Solar power comes from the sun - and, down here on earth we’re lucky enough to have direct access. Solar panels use a thing called the photovoltaic effect to convert solar energy into electricity.

The pros and cons of solar energy:


  • Thankfully, the sun shines every day!
  • And solar power can be used after dark too, with the help of power plants that store energy in batteries and fuel cells
  • More solar storage systems are being developed.


  • Although solar panels still collect energy on cloudy and rainy days, their efficiency in these weather conditions is reduced – they’re at their best when the sun is beaming! 
  • Large-scale solar power plants take up a lot of space, which could be used for something else

Wind power 

Wind turbines harness the power of the wind, converting its energy into electricity.

The pros and cons of wind power:


  • Some parts of the world are naturally very windy – great for wind farms (and kites!)
  • Wind energy can be stored for later use.
  • Once a turbine is up, its running costs are nearly zero.


  • You can’t always predict when it will be windy 
  • A few people think wind farms are a bit of an eyesore

Tidal energy 

Tidal energy is generated by the power of the sea – the rise and fall of the tides. Energy can be generated from the tide going in and out. With two tides a day, that’s four chances of creating tidal power.

The pros and cons of tidal energy:


  • Right now, tidal power is 80% efficient – that’s pretty high!
  • Since we know the tide times, it’s a nice and predictable kind of hydropower 
  • Tidal energy can already be stored – and even better storage systems are being developed too


  • The infrastructure is pricey
  • Not that many places have the perfect conditions for a tidal power plant 
  • And these power plants might have an impact on their surrounding environment

Biomass energy 

Biomass energy is generated using organic matter. Think, natural stuff like plants and crops – and, because these can be grown again and again, biomass is a renewable source of energy.

The pros and cons of biomass energy:


  • Animal and human waste can also be used – which is cheap (if a little bit icky)
  • Using waste for energy means less ends up in a landfill. Always a good thing. 


  • Biomass crops take up space – this land could be used for other things, like growing food or forests
  • Getting energy from biomass releases carbon dioxide and methane gas, causing some air pollution

How does renewable energy work?

Fancy popping on your science hat? You can find out about the mechanics behind the world’s most popular renewables here:

And discover 20 fascinating renewable energy facts here

The renewable producing the most energy in the UK is…wind!

wind energy

Here in the UK, renewable energy sources generate nearly a third of our power – and half of that comes from wind

Wind farms are really effective in this country, as it’s extremely windy (especially at sea). And also because we’ve got a large coastline with shallow water. Which makes it easy to install wind turbines.

How renewable energy can be stored

Renewable energy can usually be stored in batteries. On a large scale, these batteries are found in power plants – but, on a smaller scale, you can also find them inside people’s homes. 

Check out our vehicle-to-grid technology trial that allows electric vehicle drivers to store power in their cars – and then sell it back to the National Grid when it’s needed.

Here at OVO, we work with partners like Kaluza, whose platform uses machine learning and AI to create a more flexible energy system. It makes use of wind-generated electricity, by storing excess power in the batteries of electric vehicles, turning them into storage devices. Clever stuff!

Storage heaters can also be used to store energy (their name is a bit of a giveaway). Learn more about different smart storage heaters in our complete guide.

By storing power in electric car batteries and storage heaters, we can help to ‘balance the grid’. Here’s what makes that so important… 

How renewable energy can meet demand

Renewable energy sources can be unpredictable, and sadly they don't meet demand yet – in other words, they don’t always give us all the power we need. When there’s not enough renewable energy to go around, we have to turn to those nasty carbon-based energy sources to top-up the supply.

But, by storing renewable energy and releasing it when needed, we can balance the grid – making sure we do have enough energy to match demand.

And we’re getting there! With the right infrastructure and energy storage in place, experts say renewables could power the world by 2050.

Why it is so important to invest in renewables

There are all kinds of good reasons to invest in renewables. 

There are financial benefits, thanks to the boom in the renewable energy industry. But the real reason to invest in renewable energy is to provide a better future for our planet and everyone on it. 

Because, unlike fossil fuels, renewable electricity won’t run ever out. It will always be there, for generations to come. It’s cleaner. It’s healthier. The more we use it, the more we shrink our carbon footprint and fight the climate crisis. For us, it’s as simple as that.

Renewable and green energy plans

Here’s what we mean when we talk about these:

Renewable energy

Renewable energy can be replenished as fast as (or even faster than) it gets used up. So, renewable energy plans use sustainable sources of energy to power your home.

Green energy 

Green energy is often used interchangeably with renewable energy. But when it comes to green energy plans, these offer other brilliant environmental benefits (as well as being powered by renewables). 

Take our OVO Beyond upgrade, for example. On top of offering 100% renewable electricity, and carbon-neutral gas1, we also help you shrink your footprint even further with personalised tips to waste less energy. Plus, we plant 5 trees2 a year on behalf of every member who signs up. 

Want to join the renewable energy revolution and fight climate change? Find out more about our energy plans.

Check our range of plans and see how much you could save now.

Our approach to renewable energy

renewable energy

We’re doing all kinds of things to get us where we need to be. From developing grid-balancing software to investing in renewable energy storage technologies. Like clever chargers that turn electric vehicles into power stations.

It’s the smart way to balance the National Grid and increase green electricity generation. So that, in the future, our country can be powered by renewables alone. Reliable, clean, better for everyone. 

All our plans come with 100% renewable electricity3 as standard. And if you want to do even more for the planet, you can. Just upgrade your plan to OVO Beyond - it’s our green upgrade that cuts carbon with renewable energy, reduces energy waste and restores nature by planting trees and protecting rainforests.

Getting renewable energy into homes

Whichever way power is generated – renewable or not – it all gets mixed up together on the National Grid. That means suppliers can’t trace where the electricity that you actually get has come from. Luckily, the UK energy industry uses a certificate called a Renewable Energy Guarantee of Origin (and EU member states use GoOs). This shows how much renewable electricity a supplier has bought, versus how much it’s sold to customers.

So, we can’t make sure that what ends up in your home will be the renewable electricity we bought for you (no supplier can). But we do show that, for every unit you use, we’ve bought the same amount of renewable electricity.

Ready to switch to a more planet-friendly energy plan? You can supercharge your journey to a lower carbon life with OVO Beyond

Check our range of plans and see how much you could save now.

Sources and references

1 If you’re signed up to our Green Energy, we purchase renewable certificates for 100% of your electricity use from green sources such as wind, solar, geothermal and hydro. Visit for more information.

We aim to plant 5 trees on your behalf in green spaces over the UK through our I Dig Trees programme. From April 2017 to March 2018 we're aiming to plant at least 150,000 trees, taking the total number of trees planted to over 500,000 trees since 2015. Find out more about I Dig Trees, here: /i-dig-trees

3 100% of your electricity comes from renewable sources such as wind, solar and hydro. The renewable electricity we sell is backed by renewable certificates (Renewable Energy Guarantee of Origin certificates (REGOs)). See here for details on REGO certificates and how these work.