British Gas is to offer free electricity for eight hours at weekends to two million customers who have smart meters installed.
Under the new FreeTime plan which launches this weekend, customers will be able to choose whether to take advantage of the deal between 9am and 5pm on Saturday or Sunday.
British Gas said the "pioneering" scheme will give customers more control over their energy use and will enable them to save £60 a year from their annual bill.
The scheme, which has been trialled with thousands of British Gas customers, will be fixed until March 2018.
Sarwjit Sambhi, Managing Director of UK Home at British Gas said: "FreeTime is an industry first. Our hundreds of thousands of smart meter customers already benefit from accurate bills and a greater understanding of their energy use.
"Now they’ll be able to enjoy doing more of what they love at the weekends, knowing their electricity usage is free during the day."
However, Andy Smale, Technical Director at Expert Energy, advised consumers to shop around in order to make even more potential savings.
He told ITV News: "While this offer may at first glance appear an attractive option to consumers, there are an increasing number of reputable smaller suppliers coming on to the market which offer even cheaper deals - even after taking into account British Gas's predicted savings."
British Gas has installed over 2.4 million smart meters in homes which provide meter readings directly to suppliers, resulting in an end to estimated bills.
Customers are provided with a smart energy monitor which shows how much energy they are using, what they are spending, and online tools to help them manage their usage.