Npower has completed the trial of a tracker tariff which offers its customers a 6 per cent discount to the standard variable tariff price cap.

The Cap Tracker 2020 has the ability to move up or down, following the movements of the energy price cap which is reviewed by Ofgem every six months.

Npower says the cap is “ideal for customers who like the confidence and peace of mind” of knowing their price is constantly tracking below the regulator’s independent index.

The trial of the tariff, which has been described as a “test and learn product”, has reached its limit and the supplier says it will now analyse the findings to see if it will offer a similar product in future.

Ofgem’s price cap came into effect on 1 January.

The regulator set the level of the cap at £1,137 on 6 November 2018, just £1 higher than the proposed level it announced in September.

According to Ofgem, 11 million households on poor value default tariffs are set to save around £76 on average, while a typical consumer on the most expensive tariffs would save more than £120.

The regulator has already indicated that if the trend of rising wholesale costs continues it is likely that in February it will announce an increase for the price cap for April 2019.