How renewable is your electricity tariff? ‘Consumers believe they’re doing the right thing – often they’re not’
A 100% renewable tariff means 100% renewable electricity, right? Maybe not. Here’s how to make sure your energy is as clean and green as possible
Say the word greenwashing and what comes to mind? You might think of fast fashion brands setting ambitious CO₂ emissions targets, but never following up on whether they’re actually meeting them, or food retailers who call their cutlery “compostable” when it only breaks down in industrial conditions. But what about energy? For most of us in the UK, the biggest concern when it comes to energy is rising costs; suppliers are far more likely to be accused of profiteering than they are greenwashing. But perhaps it’s time to put their sustainability claims under the microscope.
Fran Woodward, managing director for supply at renewable energy company Good Energy, thinks so. “We think the current system, with suppliers badging themselves as ‘100% renewable’, is greenwashing, because it leads consumers to believe they’re doing the right thing and making a difference, when often they’re not,” she says.
So what does greenwashing look like in the energy industry? It all comes down to so-called 100% renewable electricity tariffs. As it stands in the UK, consumers can be sold a 100% renewable electricity tariff without their supplier necessarily buying the equivalent amount of electricity from renewable generators. What happens is an “accounting practice”, Woodward says, that opens up the possibility of misleading consumers.
At the heart of this accounting system are renewable energy guarantee of origins (Regos). These certificates are designed to prove that renewable electricity has been produced by real renewable sources such as wind, solar, and hydro. The problem is these certificates can be sold separately from the units of power they relate to. Suppliers can buy them when they are cheapest (for example solar in the summer/wind in winter) and use them to make it appear that their customers’ usage comes from renewable sources when it may not have. It means there’s little transparency for the customer, making it easier to overestimate their tariff’s environmental impact. “There may be no correlation between when the power was needed on the grid, and when it was provided, that means we’re not reducing carbon in the way we should,” says Woodward.
In contrast, a central part of Good Energy’s strategy is a practice known as hourly matching. Woodward says: “Hourly matching is where you precisely show that at the point your customers need it – when they switch on their washing machines, or for big businesses when they’re using their power – you are making sure clean power is flowing into the system.”
Good Energy wants its customers to know where the power they’re using has come from, precisely because it has made sustained efforts to ensure it’s as renewable as possible. The company has more than 3,000 contracts with mostly independent renewable energy generators in the UK, so they can match their customers’ usage closely. That doesn’t just benefit customers – it gives renewable generators more stability, helping make new renewable projects more viable in the UK. Supporting generation in the UK also means we are less exposed to global price shocks.
Good Energy has long been ahead of the curve in advocating time matching and the industry has taken note. “We are pioneers in the supply of renewable power. We’ve been going 25 years, and we’re widely recognised as the UK’s number one for renewable power,” says Woodward. Good Energy was joint top of Which?’s Eco Provider rankings this year, was the only UK energy company to receive Uswitch’s Green Accreditation for 2026 and is number one on the Matched Clean Power Index, an independent assessment of how closely UK suppliers match renewable electricity generation to customer demand on a half hourly basis.
But even for such a forward-thinking company, it’s not yet possible to match every single unit of customer demand with renewable electricity generation in real time – and it’s transparent about it. As the Matched Clean Power Index shows, the company matches 88% within the same half hour, then 90% is matched within the same hour and everything else is matched over the course of the year.
At the moment 52% of the electricity used in the UK comes from renewable sources. To make that higher, investment needs to increase and diversify, says Woodward. “We as a country need to have more different renewable power sources: wind, solar, hydro, because they all come online at different times, depending on different weather conditions.”
Investment doesn’t always mean money, we need time invested too – into understanding our energy system, so we can be smarter about how we use it. “The more we can encourage consumers and businesses to shift demand so that there’s lower peak demand on the grid, the better,” says Woodward. This might be running machinery or charging electric vehicles at night instead of during the day. Citing the recent heatwaves, she says that this issue will only become more urgent. “Whether we like it or not, with AI and air conditioning requirements, there’s no getting away from the fact that there’s more power needed.”
For businesses, being smart about energy usage has never been more pressing. There’s the cost perspective naturally, but there are also sustainability regulations. At the moment, emissions reporting is voluntary for small and medium-sized companies, and it is likely only a matter of time before it becomes compulsory for all. Scope 2 emissions reporting is mandatory for larger companies under SECR and requires them to account for the CO₂ emissions associated with their energy consumption. Woodward advises smaller businesses to get a head start through time matching. “If businesses want to set themselves up to have a really strong reputation around net zero, then it’s in their interest to make sure that their power is time matched now.”
There are cost benefits to time matching to add to those of sustainability, Woodward says: “Businesses learn a lot about when they are using power, and it helps them think about when they can shift that power usage.”
Good Energy financially incentivises its business customers to be smart about their energy usage in this way. “We know with business that there’s the aspect of protecting the environment but it’s also – really importantly – about price. They have to be competitive, so we make it attractive for them to join us,” she says.
Time matching can also provide useful transparency as businesses do their ESG (environmental, social and governance) reporting. The level of data makes clear whether progress is really being made towards net zero targets.
As Woodward notes, the “absolute clarity” that hourly matching provides often motivates businesses to invest in generating their own power so they can generate savings too. Commercial solar and battery installation is another aspect of Good Energy’s mission to power the UK renewably.
Woodward is clear that any steps toward energy sustainability make sense for the health of a business as well as the health of the planet. “Hourly matching, in-house energy generation and smart usage all contribute to businesses knowing how to manage their cost space more effectively,” she says.