Octopus Energy has launched a new time of use tariff for smart meter customers which could see them paid to use electricity when demand is low or there is a glut of renewable power.

The Octopus Agile tariff will provide customers with half-hourly prices reflecting actual wholesale energy costs.

In a “world-first”, this will include passing on negative prices to customers through “plunge pricing” when the grid is oversupplied, the supplier said.

Customers will be alerted to “plunge pricing” via text message, email or via their online dashboard, and once a month they will be sent a full breakdown of their half-hourly energy pricing and usage.

The firm hopes the tariff will encourage the consumption of excess renewable power and claimed it could save frequent electric vehicle drivers up to £669 per year.

“This tariff is ground-breaking,” said Octopus Energy founder and chief executive Greg Jackson. “By reflecting the real cost of energy on the grid every half hour, customers can capitalise on times when prices are especially low.

“Indeed, if the wholesale price goes below 0p/kWh, Octopus Agile will actually pay you to take the unwanted energy from the grid.”

The company said there have been four such “plunge pricing” events over the last year. “As renewable energy production grows these events are only going to become more frequent,” Jackson added.