A device that allows consumers to monitor energy consumption on a regular basis and in real-time. By immediately tracking their carbon emissions, in theory customers should be encouraged to turn off appliances when not in use and to curb their energy usage. Consequently, these actions should result in lower gas and electricity bills. The meters also send information about energy use straight to the suppliers to generate more accurate billing. 
Smart meters also can offer consumers cheaper pricing on power when there is lower demand.
In order to function, smart meters need real-time two-way communications technology, which allows data to be collected remotely, rather than having to send meter inspectors to check usage. Each meter will be linked via various technologies including SIM cards provided by telecoms groups, which could also be used to control other household utilities and functions over time. 
In August of 2013, the majority of the £2.8bn contract to provide the technology behind the national rollout of 53m “smart” utility meters across Britain has been awarded to Spain’s Telefónica.The government wants every home in Britain to have a meter that can monitor and control electricity and gas to reduce power consumption, which is part of its long-term goal for a sustainable energy supply.
However, by encouraging consumers to monitor their energy consumption, the government estimates that a dual-fuel household could on average see bill savings of £25 per year by 2020.
The programme – one of the largest and most complex investment projects undertaken by the energy industry – has already been delayed by a year but it has been keenly fought over by companies in the telecoms sector in rounds of bidding.