British Gas is to trial a scheme offering free electricity on Saturdays to encourage customers to use less on weekdays.

The energy firm is testing a tariff allowing those with a smart meter to have free electricity on Saturdays. If the scheme works, it could be rolled out next year. (See our Cheap Energy Club to cut costs seven days per week.)

But only those with smart meters, which are being rolled out to all homes over the next few years, will be able to use the tariff. This is because smart meters measure when electricity is used, instead of to only measure how much energy is used.

British Gas hopes the scheme will encourage households to use electrical appliances at the weekend, when its industrial customers are using less energy. But it says it's too early to know if this will push prices up on weekdays.

Its parent company Centrica already offers a Free Energy Saturdays tariff to customers in the US. creator Martin Lewis says: "We're likely to see many such time-specific tariffs as smart metering rolls out. 

"Of course, there are precedents for this – there are already many people on Economy 7 and Economy 10 tariffs, which also push people into time-specific usage.  

"The British Gas tariff sounds innovative, yet that doesn't mean it will be the right move for everyone.

"We'll need to wait for price details to know that. So while getting a seventh of the week's electricity for free sounds appealing, it doesn't mean it'll be the right deal for everyone if the price for the remainder of the week is more expensive."  

Rising prices?

The development comes after British Gas hinted at further price rises as it announced profits from its residential arm rose by 3.2% thanks to the freezing spring weather.

The news sparked anger and calls for British Gas to keep a lid on tariffs. Finance director Nick Luff said: "We will keep prices as low as we can for as long as we can. If prices do have to go up, we will delay it for as long as possible."

Additional reporting by Helen Knapman.