Choosing a green energy tariff

Bottom Line Up Front

If you don’t have time to read this whole article, here is a brief summary:

Perhaps the simplest thing that you can do to support renewable energy generation in the UK is to buy your energy from an eco-friendly supplier. 

However, renewable tariffs can be more expensive than other capped tariffs. If you are struggling to pay your energy bills do not read the rest of this article – choose the cheapest tariff that you can. Around 38% of energy from the national grid is from renewables anyway, so some of your energy will be too. For more advice on cheaper tariffs see 

Unfortunately, because of the way that the UK energy market works, buying renewable energy is not as simple as it first appears. But, if you are willing to do some research (we provide some links below to get you started), and you can afford to pay a little extra, read on.

Much of the information in this article is from the Ethical Consumer website.

The UK Energy Market

In the UK, all of the energy that you buy from suppliers comes from the National Grid. Energy is fed onto the National Grid from a variety of energy sources at any one time. This mix varies hugely depending on demand, and the availability of renewable energy. For example, when there is a strong wind a large proportion of energy may be renewable. If there is high demand, low wind and little sunshine the National Grid may have to ask suppliers to switch on dirtier forms of generation, such as natural gas or even coal-fired power stations. You can see the current energy mix for the National Grid here: and 

A significant proportion of the UK energy mix is now renewable. Over the year to March 2023, 34.5% of our energy came from renewable sources. So it is likely that, even if you don’t go for a green tariff, a proportion of your energy will be renewable anyway.

100% Renewable Electricity Tariffs

There are two ways that energy suppliers can claim a ‘100% renewable’ electricity tariff. 

The first is for the company to buy certificates (known as REGOs). The money from REGOs is intended to go towards the building of new renewable infrastructure. Unfortunately the market for REGOs has made them so cheap that they only provide marginal support for this.

The second approach is to directly fund new renewable infrastructure, either by owning that infrastructure themselves or by having contracts with renewable suppliers. So, by having one of these green tariffs you will be contributing towards renewable energy infrastructure. Beware though that such companies are exempt from the current government energy price cap, so their tariffs are likely to be more expensive.  

So, if you can afford to pay a renewable tariff, and you have done sufficient research to be happy that you are genuinely paying for an increase in renewable generation, then please do so. If nothing else it will help to signal to the market that renewable energy (and potentially other ethical concerns as well) is important to consumers. A good place to start your research is here: There are further useful links at the bottom on this page.

If you can’t afford it, or you aren’t sure, then don’t worry, a proportion of the energy you use will still be generated from renewables and some of your bill may still be going towards environmental schemes via the social and environmental obligation costs that all large suppliers must pay. For more information about these see

You can also look at alternative ways to lower your carbon footprint on the rest of our website.

Electric Vehicle Tariffs

If you have bought, or are planning to buy, an Electric Vehicle (EV) then you should be aware that charging it at home will greatly increase your energy consumption and may cost 100s of pounds per year.

EV specific tariffs offset some of this cost by offering periods (usually overnight) when your electricity charges are much cheaper. This is possible when demand on the National Grid is low (especially when renewable generation may also be high, such as during high winds) and wholesale energy is therefore much cheaper.

Some tariffs may also work with your smart meter to change your EV charging time (while still meeting a target battery level that you set) to match the cheapest wholesale energy price.

Unfortunately due to the government energy price guarantee most providers have stopped offering EV tariffs. Keep an eye on the Money Saving Expert website to see when they return to the market.  

Gas Tariffs

Most of this article is about electricity, but many of us (around 86% in the UK) are on mains gas supplies as well. As with electricity, there are two ways that a company can claim an ‘eco-friendly’ gas tariff. One is by buying gas from bio energy sources (such as processed animal manure or other bio-wastes) or through offsetting using certificates. 

Both approaches have their critics. If gas is genuinely being generated from waste products, that would otherwise release methane into the atmosphere, then this does help climate change, as the methane is converted to CO2 when it is burned. Methane is estimated by the IPCC to be three times worse for climate change in the short term than CO2. If however crops are being grown specifically to convert to biogas then this may be taking land away from other uses such as food production.

Energy offsetting is a hugely complicated subject but, in short, it is very difficult to prove that an offset genuinely results in a cut in emissions since offsets may pay for environmental schemes that would happen anyway, funded from elsewhere.

A good place to start your research is here:  There are also more useful links at the bottom on this page.

Further Reading

To see where suppliers actually get their energy from, you can find fuel mix graphs for electricity suppliers at

Ethical Consumer magazine/website provides scores for energy suppliers using both environmental and ethical criteria. You can customise scoring criteria through the link at Other criteria for selecting a supplier should also be considered e.g. customer service.

Switching Supplier

There are many switching and price comparison websites, some of which allow you to filter results by green tariffs. Note however that many of these services are paused while the government energy price guarantee is in place. Check back later to see when they offer this service again. 

Ofgem provide general advice on switching energy supplier at  including a list of accredited price comparison websites which may also offer a direct switching service. Please bear in mind these websites earn commission, so may not include all available tariffs.

On the Money Saving Expert ‘Cheap Energy Club’ search results page, you can apply a ‘100% Renewable’ filter – see
Green energy comparison and switching services include: