Wholesale energy cost increases mean there are currently no cheap deals available in the market, and now may not be the best time to switch energy supplier. In addition, some claims made by green energy suppliers are being investigated over concerns their environmental benefits may have been exaggerated.
In normal times, switching to a green energy supplier is easy. Many energy suppliers (opens in new tab) provide 100% green electricity - most of the Big Six energy companies (British Gas, EDF Energy, E.ON, Npower, Scottish Power, and SSE*) have tariffs that offer this. However, if you want green gas too – or at least a certain portion of it – you’ll have to turn to one of the smaller energy suppliers.
The good news is that - in normal times - green energy doesn’t have to cost you more. Prior to the energy crisis, our ongoing energy comparison (opens in new tab) research continually showed that some of the cheapest energy suppliers were green energy companies.
Bear in mind that just because you've signed up to a green energy supplier, there's no guarantee – and no way of ensuring – that what comes out of the National Grid into your home is actually green. However, the energy that goes back in to replace what you've used will be green.
We don't recommend switching right now, but when the time comes, switching energy supplier (opens in new tab) is easy. It takes less than two minutes to get a quote from the best green energy suppliers: all you need to do is provide your postcode (because energy prices differ across the country) and a few details about the property you live in, such as how many bedrooms there are. Then simply choose the best energy deal (opens in new tab) for you.
We're currently reviewing how we rank green energy suppliers. The rest of this guide hasn't been updated since the energy crisis started.
The best green energy suppliers in the UK(opens in new tab)
Octopus Energy is the best green energy supplier for customer service – and for the second year running, it's a Which? Recommended Provider too. As well as winning awards for customer satisfaction, 97% of the company's 22,000 reviews on Trustpilot are rated good or excellent. That's very rare for an energy company, and means Octopus has the maximum five star rating on Trustpilot.
Octopus has strong green credentials, too. When you choose its Super-Green tariff, Octopus will supply 100% renewable electricity, and the provider promises to ensure that any carbon involved in the production of your gas will be offset. It does this by partnering with Brighton-based charity Renewable World, which specialises in carbon-reduction projects in the developing world.
- See how Octopus's prices compare with other providers
- Read more: Octopus review (opens in new tab)
Green Energy UK is the only supplier to offer 100% green gas as well as green electricity, making it the only true green energy supplier in the UK. You’ll have to pay more for these green credentials though, because Green Energy UK is exempt from the Ofgem price cap. In fact, the provider was 38% more expensive when we did a price comparison of all the suppliers mentioned in this guide.
We signed up to Green Energy UK and found the switch to be very easy, with plenty of information from the company. We've received very good customer service since, and billing has been accurate. The company averages 4.5 out of 5 stars on Trustpilot, albeit over a smaller review pool of around 800.
If you're looking for a truly green choice, Green Energy UK is it. However, just make sure the company has the correct meter readings: if your energy use has been estimated incorrectly and you're hit with a 'catch-up' bill, you'll know about it.
- Get a free quote from Green Energy UK now (opens in new tab)
Outfox the Market is the cheapest green energy supplier available. The company claims to pass on the best prices to customers with a no frills approach, but the number of negative reviews online is concerning (21% of nearly 26,000 Trust Pilot reviews are 'poor' or 'terrible'). Recently, Outfox the Market scrapped its old membership charge in favour of the typical standing charge like all the other suppliers. They may be the cheapest, but it’s worth noting that the best supplier, Bulb, is only a little more expensive and is far more established with much better customer service.(opens in new tab)
Npower is the best Big Six supplier for green energy because the company offsets carbon, plants a tree when you switch, and has been audited by EcoAct – which certified that its Go Green Energy Fix meets its green standards. Npower’s prices are firmly in the middle of the range, and if you pay by direct debit you’ll get a discount. Plus, it's the only energy provider to have received triple certification from the Carbon Trust Standard, recognising its commitment to reduce carbon, water and waste from its offices.(opens in new tab)
Ecotricity is the only energy company in the UK to be recognised by the Vegan Society and get its stamp of approval, making it the only vegan energy choice. Its prices are expensive, but if you care more about ethical suppliers than cost, it might be the best choice for you. Ecotricity funds and supports anti-fracking campaigners in England, and has followed in the footsteps of Extinction Rebellion to declare a climate emergency. It also generates its own green gas, although you won’t get 100% green gas from the company. Just beware the negative reviews around closing accounts and switching away from Ecotricity on Trustpilot.(opens in new tab)
OVO Energy started in 2009 as one of the new breed of digital challenger brands looking to take on the Big Six. Ironically, since acquiring SSE and its 3.5 million customers at the end of 2019, OVO is now technically one of the Big Six, though for now they plan to run the two brands separately.
OVO prides itself on excellent customer service. While it fails to meet Octopus Energy’s achievements in this regard, 87% of nearly 37,000 Trustpilot reviews rate them ‘excellent’ or ‘great’, nonetheless, with only 9% ‘poor’ or ‘bad’. However, it remains to be seen what going from challenger green energy supplier to Big Six will mean for its vision and values.
Find the best green energy deal for your home | T3 and GoCompare (opens in new tab)
Use our energy comparison tool to find the best green energy deal for your household in minutes. Simply filter your results to show green suppliers, choose your tariff, and we'll take care of the switch for you. Plus, because we’ve partnered with leading comparison site GoCompare, you'll get access to exclusive energy deals that you won’t find elsewhere.
Other green energy suppliers to consider
Interested in what else is out there? Here are a few more leading green energy companies in the UK that are looking to shake up the energy market.
Other energy suppliers with green tariffs
If you're not convinced about switching to a smaller green energy supplier, here's our pick of the best bigger energy companies that also offer a good green tariff.
E.ON gives all its customers 100% green electricity, and its Fix Online v4 tariff is one of the cheapest around. The company is leading the way with generating green energy, and since 2017 has invested more than €9.5 billion in renewables – but E.ON didn’t take the top spot as best Big Six supplier here because it has a lot of negative reviews on Trustpilot. Get a quote from E.ON now (opens in new tab)
ScottishPower offers green energy for a monthly fee of £3 with its Go Green Bolt On. It sold its gas plants and closed its coal-fired power stations, further boosting its green credentials. And while ScottishPower ranks well in some customer polls, it’s got a poor profile on Trustpilot, so we haven’t recommended it as one of the best green energy suppliers. Get a quote from ScottishPower now (opens in new tab)
British Gas gets 43% of its electricity from renewable sources, but its green tariffs will match 100% of the electricity you use with renewable electricity, and offset the carbon footprint of the gas. It has a number of green tariffs to choose from, depending on how long you want to fix the price for, or your energy use habits, but it's one of the more expensive green energy suppliers. Get a quote from British Gas now (opens in new tab)
What is green energy?
Green energy is simply electricity and gas that’s generated from renewable sources instead of fossil fuels like coal and gas. 'Green gas' refers to Biomethane, which is a naturally occurring gas produced from the breakdown of organic materials and landfill gas. Green electricity, meanwhile, is the electricity produced from renewable sources in the following ways:
- Wind power, where wind provides the mechanical energy to turn turbines
- Solar power, where sunlight is absorbed by photovoltaic panels
- Hydroelectric power, where fast-flowing water drives the turning of turbines
- Wave power, where the motion of waves drives tools like hydraulic pumps
- Tidal power, where the rise and fall of the tide pushes turbines
Is green energy more expensive?
Green energy isn’t necessarily more expensive. The cheapest suppliers in our price comparison were Outfox the Market and Pure Planet, which are both green energy companies. That said, the most expensive in our price comparison – Ecotricity and Green Energy UK – are also green energy suppliers.
The price difference is usually down to just how green the energy really is. You’ll usually pay more for a supplier that generates its own electricity from renewable sources and provides some level of green gas, and pay less if the supplier simply matches your usage by buying green energy.
Regardless of the supplier you choose, there are a few tips on how to keep your energy costs low:
- Consider a fixed-price tariff. Your costs will be frozen so you’ll avoid any price hikes
- Request a smart meter to keep an eye on your energy usage
- Wash your clothes on a lower temperature
- Turn off appliances when they’re not being used
- Put your heating on a timer
- Draught-proof your property
- Shop around for energy quotes (opens in new tab) - but don't be swayed by price alone. Check fuel mix, customer service and reviews to get a fair picture.
- Try a tool like Energy Monitor that will alert you when you could switch tariffs to save money.
How to choose the best green energy supplier
When you’re choosing a new green energy supplier you need to check their fuel mix and see if they can guarantee you’re getting green electricity – or if they’ll just offset your usage. You’ll need to decide which option is right for you.
You can find out what type of energy your supplier uses by looking at their fuel mix. Each year, energy companies must report to Ofgem exactly how their energy is generated, which gives us a fair way to see which suppliers are truly green and which still rely on coal, for example.
You also need to think about the stability of the supplier. You may fear that a smaller company is less reliable – and the news that many have gone bust in the last 18 months won’t allay those fears – but it’s worth knowing that even if your provider goes bust, your supply won’t be interrupted, you’ll just be moved to a different supplier.
It may well be worth the switch: the smaller suppliers tend to have better service and much happier customers, according to customer satisfaction polls. And some, like Bulb and Octopus have become as well-known as the Big Six suppliers.
* OVO Energy completed its acquisition of SSE in January, 2020, but announced that it intends to keep the two brands distinct, at least for the foreseeable future.