Do you flex yet? John and Barbara Hall do. Their home is part of a £5.3 million government trial to shift consumers’ energy use to when it is clean and cheap. The retired couple save money by using more electricity while it is windy or sunny — and less during busy, expensive times.
Energy geeks call this “demand flexibility”. In a net-zero future, this must become the new normal in British homes. “It’s not optional. It’s absolutely essential,” says Izzy Woolgar, director of Centre for Net Zero, a research institute founded by Octopus Energy. She says that not only is demand flexibility the “cheapest way” to balance the grid and keep the lights on without firing up gas power plants, “it can bring down energy bills for everyone”.
A more flexible energy system would avoid the need for four new gas power stations by 2030. By 2040, it could save Britain £14 billion a year and halve every household’s wholesale electricity costs to save up to £375 annually, according to Cornwall Insight, an energy consultancy.
For the Halls, flexing started with an app. Last year, Mr Hall, 63, became one of 7,000 residents in Oxfordshire where the technology is being tested to download the Energy Saver App on to his phone. It gathers data about a household’s energy use from their smart meter and analyses it to give personalised advice on how to cut bills and carbon emissions. Users can compare their energy consumption with previous months and with similar homes. “Uh oh,” it warns when you seem to use an “abnormal amount of energy”.
Usefully, the app shows which devices consume the most energy. “It highlighted that 21 per cent of our daily electricity use was from fridges,” Mr Hall says. “We were running three fridges so I turned one off for the winter.”
The same functionality prompted Jessica Gasper, 41, another Oxfordshire app user, to turn off all devices on unnecessary standby in her young family’s Victorian terrace. As a result “always on” appliances dropped from 11 per cent to 5 per cent of their electricity use. “If you can see those figures changing, you get some sense of control over your bills,” Gasper, a physiotherapist, says.
The app also lets users switch energy tariffs “from a completely impartial standpoint”, says Dale Hoyland. He is the retrofit team leader at Oxfordshire county council, which partnered with the data platform Metis and the Department for Energy Security and Net Zero in the demand flexibility trial. Their findings will inform future energy market reforms. App users are saving £200 a year from the app’s insights and a further £100 a year through switching tariffs, Hoyland says.
In its next phase the trial will fit solar photovoltaic panels and 5.2kWh GivEnergy batteries in 500 Oxfordshire homes. Residents pay no upfront costs — making a low-carbon home “almost as simple as a mobile phone contract”, Hoyland says. The panels (typically costing £6,000 to £8,000) are free and households pay £40 a month to rent the battery (which can be installed for about £3,000). This should cut a net electricity bill by more than £1,000 a year, according to Hoyland.
The Oxfordshire trial will also fit 200 air-source heat pumps, discounted by £10,000 each (including a £7,500 government grant). Installing batteries, solar panels and heat pumps for more homes means flexing no longer relies on behavioural change. Instead, the machines “do it for you”, Hoyland says. It means no one has to think about waiting until after the 4pm to 7pm peak to cook dinner for their hungry children.
The Halls were the first in the Oxfordshire trial to have 4.5kWp (kilowatt peak power) solar panels and a 5.2kWh battery, fitted just before Christmas. “It changed our electric usage quite dramatically,” says Mr Hall, who estimates their monthly consumption fell by a quarter in January, despite the cold weather. “Most people like us just can’t afford to lay out £8,000 to £10,000 for a system like this and then try and get it back over the next 10, 12 years,” he adds. The trial has taken the upfront cost away “so happy days”.
In time artificial intelligence is expected to automate home energy use “without people even having to think about it”, Woolgar says. “It will happen seamlessly in the background, much like when you plug in your iPhone overnight, and it smart charges, you wake up in the morning, and it’s ready to go.”
However, she warns that there is a “mountain to climb”. Consumer flexibility has to increase four to fivefold by 2030, according to the National Energy System Operator (Neso).
To start flexing consumers can opt for a smart meter and switch to a time-of-use tariff, where the supplier passes on savings when wholesale energy is cheaper.
Consumers can also join Neso’s “demand flexibility service”, which has paid consumers between £1 and £5 every time they cut their electricity usage during specific peak events. It paid out more than £20 million over the previous two winters. However, participation plummeted from 2.6 million households to about 1.73 million after payments were reduced by as much as 90 per cent, according to Woolgar.
“What’s missing from the conversation at the moment is the increasing need for consumers to turn up,” she adds. “We’re paying wind farms about £1 billion a year to turn off because we’re not using that wind power. That number is set to triple, potentially even more, by the end of the decade. We need to be asking consumers: ‘Hey, the grid is going to be really green and cheap this evening. We suggest that you run a wash or do your cooking in that period.’ You might even be offered free electricity.”
Ultimately, Woolgar says, flexibility means “we are paying people rather than power plants, to support the energy system”.
