Households with solar panels risk being overcharged by smart meters

Households with solar panels risk being overcharged on their energy bills if they have a smart meter fitted, it can be revealed.

Some have seen their energy bills more than treble after smart meters have been installed. This is because, while the two devices are capable of working together, energy firms say they are unable to access correct information about excess energy being generated by people's solar panels.

It means nearly a million households in Britain with solar panels on their homes could face billing chaos or being excluded from the Government's roll out of smart meters.

Two of Britain's biggest energy companies, EON and NPower, are refusing to install smart meters in people's homes if they have solar panels. 

Meanwhile other firms, including British Gas, are fitting smart meters into homes with solar panels, But this has resulted in billing issues for some customers, who have ended up having their smart meters removed. 

The Daily Telegraph can also reveal that energy firms are working with Government to develop an urgent fix to make the two energy saving "green" schemes function together without penalizing consumers.

It is just the latest in a string of technical woes affecting the £11bn rollout of smart meters to every home in Britain by 2020.

One British Gas customer paying £17 a month for his energy bills said he saw his payments treble to £44 after getting a smart meter fitted.

He complained and the meter was eventually removed and replaced with digital meter, after which he says his bills returned to normal.

British Gas said this was not caused by the smart meter, and that his old meter was malfunctioning and under-recording his usage.

Billing problems are arising for households with solar panels because they are paid for energy generated by the devices based on half of their estimated energy usage.  But under Ofgem licencing rules energy firms must pay homes the exact amount of energy they export if they have a smart meter. 

Although smart meters are capable of getting accurate readings energy, some firms say they are unable to access this information because the network which connects them to people's smart meters cannot provide accurate export data  This means they must either pay an estimated amount or send someone to read the customer's smart meter.

A source at one energy firm said: "The received wisdom is that people would be a lot worse off [if they get a smart meter] because this deemed amount is pretty generous. If you are using most of the energy you generate then you could be making quite a significant profit."   

An Ofgem spokesman said it was aware some energy firms were using estimates rather than the actual amounts for households' energy sent the grid.

He said: "We understand that this is because, at the moment, the supplier can’t always access the export meter readings. We expect suppliers to work to resolve this issue." 

A BEIS spokesperson said energy firms were to blame, saying: “Smart meters are compatible with microgeneration, including solar panels."

Have you had problems with smart meters and solar panels? Have your bills increased? Email sam.meadows@telegraph.co.uk