A revision to the way energy bills are calculated will allow for unused ‘cheap’ units to be saved for later use, Finance Minister Clyde Caruana has announced.

He said the new system will prevent consumers being faced with “surprises” on their bills at the end of the year.

Caruana did not provide a timeline for the revision process. 

The ARMS billing system has long been criticised for overcharging consumers.

A draft report by the National Audit Office (NAO) has found that consumers could have paid “extra charges” totalling €6.5 million on their electricity and water bills.

The as yet unpublished report by the Auditor General’s office calculated a variance of €4.6 million in electricity bills and €1.9 million variance in water bills.

Caruana said the new system will allow consumers to save unused cheap units that can then be redeemed during periods of high consumption.

The finance minister said the current billing system was created by the Nationalist Party in 2009.

He insisted the system has remain unchanged since then, apart from a tariffs reduction in 2013.

Caruana said the new system would not impact the feed-in tariff or eco-reduction.