1817

First Gas meter used in Royal Mint in London.

1851

Gas meters used first in London and then in other cities, to measure the amount of gas provided to streetlights.

1889

1st WattHour Electricity meter - the basic 'spinning disc' technology is still used in many meters worldwide.

1899

First Electricity prepayment meter is introduced in America, with the design being introduced to the UK the following year.

1923

Introduction of early gas meters across homes.

1931

Roll-out of standard clock-face meters across the UK.

1968-1975

Conversion from town gas to natural gas (the last major energy initiative involved visiting 13 million homes. The smart meter roll-out will involve visiting 25 million homes).

1976

First non-analogue meters are introduced for businesses, to replace traditional 'clock face' dial meters.

1980

Introduction of solid state and digital metering in homes.

Mid 1980s

Gas and Electricity Coin meters replaced by newer types of prepayment meters using tokens, plastic keys and eventually cards with embedded chips.

1990s

Introduction of Automatic Meter Reading by a number of utilities.

2009

Smart meters featuring two way communications and remote access to data are mandated for roll-out across Great Britain.