Skip to main content

Slashing your carbon footprint has never been easier …  

We are teaming up with Big Clean Switch to make it as easy as possible for you to switch to a renewable energy provider. Using the Big Clean Switch website, it’s simple to find a trusted green supplier, and can save a typical home about £285 a year.

How to switch in three easy steps:

  1. Click here to go through to the Big Clean Switch website
  2. Pop in a few details to compare the green tariffs on offer to your current supplier.
  3. If you like what you see, it takes a couple more minutes to complete the switch – that’s it.

We'll be offering you the chance to switch until 5pm on 20 April, with special tariffs available during this time.

Want to know a bit more detail about green energy tariffs and how the switching process works?


Frequently Asked Questions

The basics

Who can I speak to if I need help?

If you have a question about switching, email the Big Clean Switch at Alternatively, you can phone them on 0800 249 4770.

If you have a question about WWF or our collaboration with Big Clean Switch, contact our supporter care team on 01483 426333.


What is ‘renewable electricity’?

The main renewable electricity sources are:

  • Wind power

  • Solar power (the power of the sun)

  • Hydro power (using dammed or moving water to generate electricity)

  • Biomass/biofuels (producing energy by burning organic materials such as food waste or sewage )

  • Tidal and wave power (using the movement of our oceans to generate electricity).

You can find out the renewable energy mix of the suppliers offered through Big Clean Switch by visiting here.


Why is renewable electricity a good thing?

Traditionally, electricity has been generated by burning fossil fuels – mainly coal and gas. Generating power in this way releases greenhouse gases, such as carbon dioxide, into the atmosphere which contribute to climate change. There is global agreement that we need to massively reduce our dependence on fossil fuels. Burning fossil fuels, particularly coal, also causes air pollution.

In contrast, generating electricity from wind, solar or hydro power does not release greenhouse gases or other air pollutants. A small amount of greenhouse gases may be produced in construction, but the overall impact is significantly smaller, making them a much cleaner option.


What is ‘clean electricity’?

‘Clean electricity’ is sometimes used interchangeably with ‘renewable electricity’. Electricity generated from renewable sources is considered ‘clean’ because when the electricity is generated it does not release greenhouse gases and other pollutants - unlike, for example, coal power plants. Also, wind, solar and hydro power do not contribute to air pollution.


Isn’t renewable electricity expensive?

Far from it. As more and more renewables have been installed in the UK, so the costs of building and installing the equipment have fallen - and the technology has improved. According to government numbers, onshore wind and solar are already among the cheapest new sources of electricity generation in the UK; they, and offshore wind, will all be cheaper than new gas by the early 2020s.

That translates into cheaper renewable tariffs for consumers. The difference between an average Big Six standard variable tariff and the cheapest 100% renewable electricity tariff available through the Big Clean Switch is around £230 a year.

You can find out whether a renewable tariff would be cheaper for you by entering your details into the Big Clean Switch comparison site. It will compare your existing tariff with clean suppliers and give you an estimate of potential savings.


What is Big Clean Switch?

Big Clean Switch is part of Brakkn Ltd, a ‘profit with purpose’ company that aims to accelerate take-up of renewable electricity by making it easy for homes and businesses to switch to green energy providers.


Who can I switch my energy to?

Big Clean Switch offer a growing panel of vetted suppliers, so you can choose the right tariff for you, all at a competitive price. Currently the suppliers on offer are Bulb, Bristol Energy, Co-op Energy, Ecotricity, Good Energy, iSupply, Octopus Energy and So Energy.


What happens at the end of the three week switching window? Can I still switch?

Yes, the WWF page will remain open for you to switch through for the foreseeable future. Certain tariffs will not be available though after the three week period is over on 20 April.


About 100% renewable tariffs

Doesn’t all electricity come from the National Grid? How do 100% renewable electricity tariffs work?

When you’re on a renewable electricity tariff, your supplier promises that, however much electricity you use in your home, the same amount of renewable electricity will be put into the National Grid. The more this happens, the cleaner the Grid will get - and the more demand there will be for renewables, that will help fuel greater supply of renewables. Because you’re still getting your electricity from the National Grid, there’s no need for engineers’ visits and no disruption to your supply when you switch.


Is there a risk that I’ll lose power when the sun doesn’t shine or the wind doesn’t blow?

No – you’ll still get your electricity from the National Grid, which manages the UK’s electricity supply to ensure everyone always has enough power.


Can I get clean gas as well as electricity?

By replacing fossil fuels with energy from the sun, wind and water, we can generate clean electricity without the pollution and carbon emissions. Gas for heating and hot water is currently harder to replace, but it is possible to generate gas from plants (including food waste).

Green gas can be produced from a number of sources including biogas from anaerobic digestion, landfill gas and synthetic gas (‘syngas’) from the gasification of biomass. With a demanding EU target for renewable heat as well as renewable electricity and transport fuel, UK producers are now starting to convert the gas into biomethane  and inject it directly into the gas distribution network. Gas injected in this way displaces fossil-derived natural gas giving some savings in greenhouse gas emissions.

However, so far, this lower carbon gas still makes up a very small proportion of the gas used by UK homes, so very few suppliers offer ‘100% renewable gas’ in the same way as you can get 100% renewable electricity. If they do, they will be shown on the Big Clean Switch website in the tariff description. Bristol Energy are offering WWF supporters a 100% green gas tariff. The green gas is sourced from GENeco's gas-to-grid plant at Bristol sewage works that is 100% waste product, 100% UK sourced . GENeco's gas to grid facility is registered with the Green Gas Certification Scheme (GGCS), a system that tracks biomethane, or 'green gas', through the supply chain to provide certainty for those that buy it.

A secondary option, which some suppliers offer, is to offset your emissions associated with your non-renewable gas use. This means that the supplier will charge you more for the gas you use, and use the extra money to support projects that reduce greenhouse gas emissions by an amount equivalent to the emissions from your gas. Although this is a positive step, we would encourage suppliers to move away from fossil fuels. For more information on offsetting, visit the United Nations Framework on Climate Change website at


Are some renewable tariffs ‘greener’ than others?

Every tariff available through the Big Clean Switch website guarantees that for every unit of electricity you use, an equivalent unit of renewable electricity has been put into the Grid. This ensures that every tariff is helping to support the UK’s transition to a low carbon economy by driving up demand for renewable electricity. Tariffs and suppliers will still differ, however, in three ways:

Which renewable energy sources they rely on

You can see how the renewable energy mix of the suppliers listed on the Big Clean Switch vary on their ‘About us’ page.

Whether they source their energy directly or indirectly

Whenever a renewables generator (a wind farm, for example) produces a unit of power, the government issues them with a certificate (known as a renewable energy guarantee of origin (REGO) certificate) proving they’ve put green energy into the Grid. Some generators then sell their electricity directly to suppliers, in which case they pass on the certificates at the same time. Other generators sell their electricity on the wholesale market, in which case they retain the certificates. If your supplier then buys some electricity on the wholesale market, they can buy a matching amount of REGOs to prove that an equivalent amount of electricity has gone into the Grid. Whichever approach your supplier uses, you know the electricity you use is matched by renewable power, but if your supplier is buying directly from generators, there is a more direct link between your consumption of energy and the generators that produce it.

Whether they also supply green gas

Very few suppliers currently offer 100% green gas in the same way they do for electricity. Where a supplier does source a significant proportion of its gas from renewable sources (mainly biofuels generated from rotting plants and food), this is indicated on the Big Clean Switch website in the tariff description.


About switching

How to switch - three easy steps:

  1. Shortly after Earth Hour, we’ll email you with a link to Big Clean Switch.

  2. Pop in your details to find out the renewables tariffs on offer to you.

  3. Like what you see? Switch there and then. It only takes 5 minutes and Big Clean Switch do all the work for you.


Is it easy to switch?

Absolutely. Once the tariff is live, just pop in a few details about your energy use (a previous energy bill will have everything you need) on the Big Clean Switch website to get a tailored quote. If you like what you see, it takes a few more minutes to sign up. Then just sit back and relax, Big Clean Switch do all the work for you – no need to contact your old supplier and no need for engineers’ visits.


How does switching supplier work?

The word ‘supplier’ is actually a bit misleading, because most people’s electricity is supplied by the National Grid. The companies you pay for your electricity and gas should really be called ‘sellers’, because they sell the energy in the Grid to you. That means that no matter who sells us the energy, it still comes from the Grid. No interruptions of supply, no visits from engineers – just a different name on your bills.


When will the switch actually take place?

Once you’ve completed your switching application with the Big Clean Switch, Big Clean Switch will send your details to your new supplier. Submitting your application also starts a 14 day cooling off period, during which you are free to change your mind and cancel your switch. In practice, most of the suppliers we work with don’t charge leaving penalties, which means you’re free to leave them at any time if you choose.

During this 14 day period, your new supplier will contact your current supplier to let them know you’re moving, make sure your account is in order, and set a date for the switch (which they’ll then tell you about). This is typically about three weeks from the date of your switch application. On that day, you’ll stop paying your old company for your energy (they’ll send you a final bill up to that date), and start paying the new one. You may be asked to submit a meter reading on that day, too.


Will I get the same quality of customer service?

All the suppliers available through the Big Clean Switch have been vetted to make sure their customer service and environmental credentials are up to scratch. That’s why, in the unlikely event you have a problem that you can’t resolve with your new supplier, Big Clean Switch promise to take it up with them on your behalf.


Will I be charged for switching?

No, switching is free. Big Clean Switch is funded from commission paid by suppliers. This doesn’t affect the price of the tariffs we offer (which are the same as the ones you’d find on suppliers’ own websites other than where Big Clean Switch have negotiated an even better deal.)


Will the tariffs change price over time?

The price of energy is affected by a number of factors, such as changes in wholesale prices or technical problems at power plants which might restrict the amount of energy going into the National Grid. Different suppliers are affected by changing prices in different ways, depending on how they buy the energy they then sell to you, but most eventually pass on price increases (and less consistently, price falls) to their customers. If it’s important to you that you keep your bills to a certain level, you can protect yourself against price rises by opting for a fixed rate tariff. This means that, whilst the amount you pay will still go up or down depending on how much energy you use, the price you pay per unit of energy will stay the same for a set period (normally 12 months). The alternative to a fixed rate tariff is a variable rate tariff. If you’re on a variable rate, your supplier can change how much they charge for a unit of electricity at any time (although they have to give you enough advance warning to allow you to move to a different supplier if you’re unhappy with this).


What’s the difference between a fixed rate tariff and a variable tariff?

You may have noticed that they come in two types – ‘fixed’ or ‘variable’.

Fixed tariffs

When you sign up to a fixed tariff, the amount you’re charged for a unit of energy will stay the same for a set period (usually a year). The total amount you pay could still go up or down depending on how much energy you use.

If you leave a fixed tariff before the end of that set period, some suppliers may charge you a penalty fee, which will be added to your final bill. And when you come to the end of a fixed tariff, you’ll usually roll onto the supplier’s most expensive variable tariff, so remember to switch again before this happens.

Variable tariffs

When you’re on a variable rate tariff, your supplier can increase or decrease the amount they charge you for a unit of energy, providing they give you at least 30 days warning. Unlike fixed tariffs, there’s no charge for leaving a variable tariff, so if the price does change, you’re free to go elsewhere.

Which is right for you?

If you want the certainty of knowing that the price of the energy you’re buying won’t change for a set period, opt for a fixed tariff. If you don’t mind uncertainty (and remember prices can go down as well as up) and would rather not have to switch at the end of every fixed term deal, then a variable rate may be better for you.


Are there other renewable tariffs available? Are they cheaper?

Big Clean Switch works with a select group of suppliers, all of whom have been screened to make sure their customer service and environmental credentials meet certain standards. You can read more about their criteria for listing a supplier or tariff here. While Big Clean Switch aims to secure tariffs that offer a combination of environmental benefits, competitive pricing and good customer service, there may be other tariffs available - both green and non-green -  that are cheaper. If you need to find the very cheapest tariffs available, consider using a whole market comparison service like EnergyHelpline. As with any financial contract, please be sure that the cost of the tariff is suitable for your financial situation, and that you are able to make the payments before switching.


Do I need to contact my old supplier to let them know I’m switching?

No. Big Clean Switch will let your new supplier know that you want to switch to them, and they’ll contact your old supplier for you. If your old supplier confirms that the account isn’t in arrears, your new supplier will then confirm the switch date with you.


Do I have to pay to leave my current supplier?

If your current supplier has promised to keep the price you pay for a unit of electricity the same for a certain period (known as a ‘fixed tariff’), then they may charge you a penalty for leaving them before the end of that time (usually a year, although some fixed tariffs last longer). However, switching may still be worth your while if the savings outweigh the penalty. If you think an early-leaving charge might apply to you, give us a ring on 0800 249 4770 and we can talk you through the options.


I’ve never heard of the suppliers on your site. Can I trust them?

It’s understandable to be concerned about switching to a company you’ve never heard of, but in fact most renewable energy suppliers are leading the way when it comes to customer service. Smaller suppliers in general make up a growing part of the UK energy market, in part because they’re often much better at looking after their customers. Big Clean Switch vet the suppliers listed on the their site to make sure their customer service is up to scratch before listing them, and because Big Clean Switch are so confident in them, Big Clean Switch make a simple promise to all their users: if you have a problem that you can’t resolve directly with your new supplier, Big Clean Switch will take it up with them on your behalf.

In the 2018 Which? Energy satisfaction survey, all of the suppliers offered through Big Clean Switch were ranked higher than the Big 6 energy companies.


I rent my home. Does that mean I can’t switch supplier?

If you pay the energy bills, then it’s your choice – if you want cleaner, cheaper energy, you can have it! If your landlord pays the energy bills, then why not ask them if they’ll switch (and let them know they could save money in the process)?


I have a smart meter with my current supplier. Can I still switch?

Yes you can, although you will probably lose some of the functionality, which will mean your having to provide meter readings manually again. Most suppliers are now rolling out a new generation of smart meters which will allow you to switch providers without this happening – you can ask your new supplier to install one of these. If you’re concerned about losing smart meter functionality, it’s best to take a note of the make and model of your smart meter and call your preferred new supplier to check with them whether they’ll be able to support it.


I’m on a fixed term tariff. Can I switch early?

You may incur a penalty for leaving your existing contract early, but with many homes saving hundreds of pounds a year by switching, you may still be better off switching now. If you’d rather wait, don’t worry – Big Clean Switch’s switching site will stay open so you can switch at a time that suits you.


I have (or am thinking about getting) solar panels – can I still switch?

Yes, absolutely. When you first install solar panels, the chances are you’ll buy your electricity from the same supplier who agrees to purchase your surplus solar energy through the feed in tariff. However, the feed in tariff agreement and the supply agreement are separate, and independent of one another, which means you are free to switch your supply to a different provider in exactly the same way as a house without solar panels. Your feed in tariff arrangement will remain unchanged, unless you choose to transfer that to your new energy provider.


I’ve been asked for my meter number. How do I find this out?

In most cases, Big Clean Switch’s system can identify your meter numbers automatically by looking up your address in a national database. Occasionally, however, this information can’t be found in the database, and you’ll need to enter your meter number manually. There are two types of meter number – one for gas, known as an MPR (meter point reference) and one for electricity, known as an MPAN (metering point administration number). If you can’t find the number on the meter itself, both numbers should be shown on a past bill. If you don’t have a past bill, then you can get your gas MPR by telephoning Xoserve, which manages the data for the UK gas industry, on 0870 608 1524. To find out your electricity MPAN, you’ll need to telephone your local electricity distributor. You can find out who this is by visiting


My switch was cancelled because my old supplier said the account was in arrears. Can I still switch?

Yes. Once your account with your old supplier is paid up to date, you can submit your switch application again – or phone us and we’ll process the switch online.


WWF and Big Clean Switch

What do Big Clean Switch do with my data?

When you enter your details into the Big Clean Switch website, they will use them to communicate with you about switching to renewable electricity; to allow you to compare the price of a range of renewable electricity tariffs with your current supplier; and to facilitate your switch if you choose to proceed. They will also share some of your data with third parties such as EnergyHelpline, which provides the price comparison functionality on the Big Clean Switch website, or to agencies they may use to help them communicate with you about switching to renewable electricity. They’ll also pass some data back to WWF to allow them to monitor the success of the campaign and ensure their communications are tailored to your needs. Big Clean Switch will never sell your data or pass it to other companies to allow them to market their own products and services. For more information on how your data will be used by Big Clean Switch, please see their privacy policy.


Is WWF’s own energy supply 100% renewable?

Not 100% yet. WWF is committed to championing making the right choices for the environment. For this reason, our main UK offices, the Living Planet Centre, was designed to showcase that it’s possible to create a state-of-the-art office space with minimal environmental impact. It is designed to use substantially less energy for heating, cooling and lighting than the average office building in the UK. The Living Planet Centre uses solar panels to produce our own renewable energy and we are in the process of reviewing our energy supplier to ensure it is fully renewable.


Does WWF get any commission from this?

No. For each switch completed, Big Clean Switch receives a commission from the energy supplier. This doesn’t affect the price of the tariffs, which are the same price (or even less) than they are on the suppliers’ websites. Once Big Clean Switch has paid for the cost of processing the switch, it passes a third of the commission to WWF. Rather than taking this money, WWF is looking to use this to fund a community energy project that is putting solar panels on schools in the Greater Manchester area. The more people we can get to switch, the greater the size of the fund available, the more solar panels that can go up! A suitable school will be chosen based on the fund available.

Go green with confidence

Switch your home to planet-friendly power today.

Find your green tariff