Chris Bowden, Managing Director of Squeaky
A Fuel Mix Disclosure (FMD) provides evidence of the mix of fuels used to generate electricity. It is shared with suppliers’ existing customers during a compliance period which runs for a year starting on the 1st April. It’s also a starting point for how you (as the customer) can understand the makeup of the power that you are buying.
If you are a business that is concerned about its environmental impact, it’s likely you’ve chosen an energy supplier based on its ‘green’ credentials. After all, powering your business with genuinely clean energy is one of the key tactics to meeting net zero.
Limitations to FMD.
The problem is though, that all is not what it first seems when it comes to FMD. In fact, there are several limitations with the FMD which means it does not give you the full picture about the energy you’re buying. In many cases, it misses out important information about the genuine makeup of the fuel mix.
One of the biggest issues is that energy suppliers can hide their use of ‘dirty’ fuels behind an eco-friendly banner of ‘renewable.’ This is why the term ‘renewable’ in the context of the FMD does not necessarily mean non-polluting, sustainable or carbon neutral.
As well as clean sources such as wind, solar and hydro power, ‘renewable’ in the FMD constitutes energy from a range of ‘brown’ sources, too. These include biomass, landfill gas and sewage gas too.
Obfuscating the truth.
Energy suppliers who buy cheap renewable energy certificates to cover up their use of fossil fuels do not need to declare them in the FMD. Energy suppliers can buy fossil fuel electricity from the wholesale market, pair it with a renewable energy certificate – a REGO or European GO – and claim it is 100% renewable. Energy suppliers are required to declare the proportion of their energy supply which is paired with REGOs or GOs, but they are not required to declare how much of their power is contracted from clean energy sources such as wind or solar.
So, even if you look at the FMD of your supplier, this loophole makes it almost impossible for you to know whether the electricity you’ve chosen to power your business contains fossil fuels, or not. And by not understanding the true source of your power, you could be at risk of greenwashing.
Ultimately it is not enough to take your energy supplier at their word on this, you will need to do your own due diligence on the FMD yourself too.
So how do you really get to the bottom of your supplier’s fuel mix? Well unfortunately you cannot, all you can really do is use the clean REGOs as a guide, but its still possible for a fossil fuel genertaor to buy 100% clean REGOs and claim to be a clean supplier. This, of course, makes the energy buying process very complex. That being said there are a few steps you can take to do your own due dillience and ease the strain a little.
1. Find out if your supplier’s REGOs are backed with clean or dirty energy.
REGO information is publicly available on the Ofgem website. In fact, REGOs are broken down by type of generation. This makes it easier to see what percentage of REGOs your supplier has paired with their energy, and what percentage it’s paired with non-clean energy. Or in other words, how much dirty energy your supplier is masking behind renewable energy certificates.
For us, clean REGOs are ones that are combined with energy that has no adverse impact on the environment. This includes hydro, ocean, photovoltaic, wind and filled storage hydro. Whilst non-clean REGOs are everything else. See visual below for more detail.

Sifting through the REGO data on the Ofgem website can be a minefield. So we’ve extracted the latest available REGO data for you. See table below.

In this table, we’ve outlined the percentage of REGO-backed energy that is clean and non-clean for each supplier.
As you can see from the above table, almost all the energy suppliers we analysed used an alarming percentage of non-clean energy backed by REGOs in their fuel mix. In other words, these energy suppliers are buying renewable energy certificates, pairing them with fossil or dirty fuels, and are declaring it as renewable energy.
There really is only one way to ensure you are buying genuinely clean energy and that is to choose a supplier who only supplies genuinely clean energy, alongside matching clean energy REGOs
2. Find out if your supplier’s energy is backed by European GOs.
In recent years there’s been a sharp rise in suppliers buying the European counterpart of UK REGOs, called European GOs. Energy suppliers in the UK submitted more than 64.4 TWh of European GOs, in the 2020-21 FMD period. This accounts for approximately 19.7% of overall electricity supply in that period. Suppliers can submit European GOs to Ofgem alongside – or instead of – REGOs for the FMD.
We’ve pulled the latest available European GO data for the UK’s key I&C suppliers and outlined the percentage of European GO-backed energy that is clean and non-clean for each supplier. See table below:

Our analysis reveals that UK suppliers are bulk-buying renewable energy certificates from Europe to disguise fossil or dirty energy in their fuel mix. Some of the biggest I&C energy suppliers in the UK are backing a significant portion of their renewable energy with European GOs. Plus, an alarming percentage of that energy isn’t clean.
Energy suppliers can legitimately submit European GOs for the renewable part of the FMD. However, there’s a host of issues when it comes to European GOs. The main issue is that buying European GOs (instead of the UK counterpart, REGOs) enables energy suppliers to wriggle out of paying green levies which are designed to support UK clean energy projects. In doing this, energy suppliers are undermining the UK’s support scheme for renewables. Not only this, but if your business buys energy backed by European GOs, you are – whether you are aware or not – also undermining the UK’s transition towards clean energy.
Regulation.
On Thursday 28 July, 2022, the UK government announced a plan to ban British energy suppliers from bulk-buying cheap renewable energy certificates from foreign power stations. Quite frankly, this new regulation couldn’t come into force soon enough.
Not only are energy suppliers manipulating their fuel mix to lure customers into buying ‘green’ tariffs, but they’re also putting their own customers at risk of greenwashing, too.
Loose regulation has long made it difficult for customers to understand where their energy comes from. This plan, which is set to come into effect on April 1st 2023, should help stamp out the deceit in the energy industry. It’s a regulation we fully supported at the consultation stage.
Clarity.
Businesses like yours – who are striving to meet sustainability targets – need clarity on the makeup of the energy they’re procuring. The most important thing you can do for your business’ transition to net zero is to buy clean energy. But with greenwashing so prevalent in the energy industry, that’s no easy task.
Ultimately it’s not enough to put trust in your supplier’s word, you need to do your own due dillience too. The only way to guarantee your energy is genuinely clean is to choose wind, solar and hydro power. At Squeaky, we only include 100% clean, traceable energy backed by matching clean energy REGOs in our portfolio of contract options.