Octopus Energy is expanding its free electricity scheme for customers at times when renewable power generation is higher than demand on the national grid. The supplier said households could get no-cost electricity during periods of strong wind and solar output, with the aim of wasting less clean power and trimming bills at selected hours of the day.

The move comes as Britain continues to pay heavily when the grid cannot take all the electricity being produced. Last year, the country spent close to £1.5billion compensating wind farms to switch off turbines when excess generation could not be absorbed. Octopus said customers had already saved £4.6million through earlier free electricity sessions under its scheme, while the company also said it had handed out £5.8million in rewards to households that cut use during peak demand.

At the centre of the push is a growing effort to shift consumption toward the moments when renewable supply is strongest. The National Energy System Operator has updated its Demand Flexibility Scheme to help manage rising volumes of renewable electricity across Britain. Under the revised setup, suppliers can encourage customers to charge electric vehicles, run appliances or otherwise increase power use when wind or solar output is especially high.

Households with smart meters may be offered free or discounted electricity during those periods, and some suppliers also hand out rewards points or vouchers. An Octopus spokesman said the rule changes mean customers can benefit from using more energy when renewables are high.

Octopus has run similar initiatives for several years through its Saving Sessions programme, but the latest expansion gives the effort fresh momentum at a time when the system is under more pressure to match supply with demand. The friction point is plain: Britain is producing more renewable electricity, yet the network still cannot always use it all efficiently, leaving consumers, suppliers and grid operators trying to turn surplus power into something households can actually feel on their bills.

For customers, the immediate appeal is simple. For the grid, the next test is whether more households will shift their habits often enough to cut waste on the windiest and sunniest days.