Participants need to opt in online in order to take part, and they don’t have long to do so, as the event takes place between 6pm and 7pm today.

The energy saving app equiwatt has also issued an alert to people who want to earn rewards for shifting their energy usage to outside of the 6pm-7pm event.

Via their powerDOWN event, energy savers can earn 100 points (worth £1) for every 1 kWh of energy saved compared to normal.

Participants must opt in via the pop-up in the equiwatt app.

Octopus Energy said customers could earn 1,400 Octopoints, worth £1.75, per kWh saved versus normal, in tonight’s session.

The firm is also offering a 100 Octopoints “streak bonus” and has announced 300 pairs of Odeon cinema tickets are up for grabs to “kick off” their new Octoplus rewards offering.

Responding to the alert on X, formerly Twitter, a customer confirmed they had “already opted in” while another told a fellow social media user: “We should be opted in to this one.”

A third person said that they found it hard to reduce energy usage during the events due to having children in the house but would try.

However, others felt the effort needed was greater than the potential reward. Among the respondents, a social media user wrote: Will stop participating on these ones very soon, too much hassle for £1.75 per kW.”

GB News has contacted National Grid ESO to find out the full list of suppliers taking part in tonight’s test event.