Plans for smart meters for millions of homes are expected to be unveiled even though trials suggest the £8bn scheme may help people save £28 a year.

Energy Secretary Ed Miliband will make an announcement later on proposals to have the energy saving meters installed in every UK household.

The Department for Energy and Climate Change wants to see 47 million meters in 26 million properties by 2020.

It is hoped the technology will help people cut down on their energy bills.

Smart Meters have a visual display allowing customers to see exactly how much electricity and gas they are using and relay the data to energy firms automatically.

Cost passed on?

Trials of smart meters have resulted in some people moderating their energy use.

Potential savings outlined already by ministers are only a fraction of the current average annual bill of more than £800 for gas and £445 for electricity.

The £28 a year figure for savings has been cited as a conservative estimate for a typical household.

But the DECC says case studies had shown people could reduce their bills by around £100 a year as the meters can encourage changes in behaviour.

It is understood that the six biggest energy firms will be responsible for the roll out of the meters at a costs of about £340 per household.

They will be able to recoup the cost from customers through higher bills or upfront fees but competition between suppliers is expected to ensure only some of the expense is passed on.

The companies stand to make big cost savings themselves, with the need for teams of meter readers becoming a thing of the past.

Mr Miliband is also expected to announce plans for a smart grid to manage the flows of electricity and to increase the use of renewable energy.