Back to top

Renewable energy: Sources, types, and definition

Renewable energy: Sources, types, and definition

Share this guide:

Last updated: 14 July 2021

As the climate changes, we as humans need to change too. Fossil fuels are fast becoming a thing of the past, while renewable energy is surely the future of electricity production. But what is renewable energy exactly? And how can you use it to your advantage on a small scale? This guide aims to explain everything you need to know. 

Save money on your energy bills

Enter your postcode below to get started

Please enter valid UK postcode.
Privacy notice information
We value your privacy; we only use your postcode to compare offers in your area.

What is renewable energy?

Renewable energy, also known as green energy, refers to gas and electricity produced from clean and natural sources. It is called renewable energy because, in theory, the source of the energy will never run out.

Renewable energy sources produce far less harmful emissions than other forms of energy, such as coal, oil, or natural gas. These fossil fuels contribute huge amounts of carbon dioxide to the environment, which studies have shown is not only bad for human health but a major contributor to global warming as well. Harmful carbon emissions which are prevalent with the use of fossil fuels are negligible when it comes to most forms of renewable energy.

Because of this more businesses than ever before are moving away from fossil fuels to focus on renewable energy, while a rising number of households are switching to a green energy supplier.

Types of renewable energy

There are various renewable energy sources that can be harnessed to create clean power:

Solar Power

Solar power is one of the most common and well-known sources of renewable energy. Solar energy is generated by solar panels which absorb sunlight and turn the sun’s energy into electricity.

Wind Power

Wind power is another common source of renewable energy. It’s usually generated by wind turbines in huge windfarms in particularly windy areas, often offshore.  

Hydroelectric Power

Hydroelectric power, also known simply as hydropower, is generated by large amounts of water flowing through a turbine, typically in major rivers and dams. 


Biomass, or biofuel, refers to renewable energy produced by the burning of organic matter such as wood. This is not the ‘greenest’ form of energy as it still produces carbon emissions but is considered renewable as it comes from natural sources. 

Geothermal Power

One of the more expensive methods of renewable energy generation, geothermal energy harnesses the heat stored deep inside the earth and converts it into electricity. 

Tidal Power

Tidal power, also known as wave power, harnesses energy from changes in the tide, which themselves are caused by the gravitational pull of the moon.

Can I generate my own renewable energy?

Yes. There are many ways that you could generate renewable energy at home which you could use to help power your household or business, cutting your energy bills whilst at the same time contributing to the fight against climate change. 

  • Solar panels can be installed on your roof. These panels absorb the sunlight and convert it into energy, which can in turn be used to generate electricity for your home or heat your water supply. 
  • Wind turbines can also be installed in some homes, although they are usually only effective in especially windy areas. Read our guide on home wind turbines for more information.
  • Biomass has been used for centuries to heat our homes, usually in the form of wood chips, pellets, or logs. 

While installing solar panels or wind turbines in your home can be an expensive investment initially, you are likely to make significant savings in the long run due to lower energy bills. However, it could be a few years until your investment starts to pay off. And the amount you save will of course depend on a number of factors, from the type of technology used to produce the energy to the size and energy demand of your home or business.

If you are generating electricity at home, it can also be worth investing in a home energy storage system, which can further improve your green credentials.

Tips for Saving Energy

As well as generating your own renewable energy or switching to a green energy tariff, you can also make small changes to your behaviour that will go a long way towards making your home more energy efficient, thus pushing your bills down further whilst also doing your bit for the environment. Here are some of our top tips for saving energy at home:
  • Turn all appliances off when they’re not being used.
  • Use your fridge and freezer more efficiently: don’t keep them open for too long, make sure they’re sealed, don’t overfill your fridge (but fill up your freezer as much as you can!).
  • Use your washing machine and dishwasher more efficiently: bigger loads mean less washes and energy used.
  • Replace your light bulbs with energy-efficient LEDs.
  • Invest in home insulation to keep the heat from escaping. 

Which companies supply renewable energy?

With the UK public becoming more eco-conscious, more and more of us are switching to so-called ‘green’ energy suppliers. But who are these green energy suppliers? And what does it actually mean to be one? 
First of all, just because an energy supplier claims to be 100% green, it doesn’t necessarily mean that all the energy they supply to you comes from renewable sources. All of the electricity generated in the UK – renewable and non-renewable – goes to the National Grid. From there it is distributed to every home and business in the country. Some energy suppliers who offer these green energy tariffs do so by matching any electricity you use at home with renewable energy production, and then feeding this back into the National Grid.
While some energy suppliers only provide the National Grid with renewable energy, for example Green Star Energy and Bulb, others still use a mix of fuels to generate their energy, like most of the Big Six energy suppliers. However, renewable energy generation is increasing among these suppliers. 
Each of our energy supplier pages includes an up-to-date fuel mix, which shows exactly where each company sources its energy from. You can use this when making a decision about when you're comparing energy deals to find your next supplier.

We are an independent and impartial price comparison website.


Our services are 100% free to use.

check is supported by its users. When you make a purchase through links on our site, we may earn an affiliate commission.

Fergus Cole

Author: Fergus Cole

Fergus is a journalist specialising in the personal finance, energy and broadband sectors. He also has a passion for travel and adventure so tries to make the most of this in any spare time he gets.

Don't miss these

A Selection of Trusted Energy Suppliers

Read on our blog

With the government poised to implement tough new measures to...

TalkTalk Confirms Huge Bills Hikes from Friday
30. 03. 2022 | Lauren Smith

Budget broadband provider TalkTalk has been notifying customers via email...

A year-long investigation by charity Citizens Advice has revealed a...

All English Schools Will Have Gigabit Broadband by 2025
23. 03. 2022 | Lauren Smith

Education Secretary Nadhim Zahawi has announced a new commitment to...