New figures show energy efficiency in New Zealand has increased over two decades.
The figures were released on Thursday by the Ministry of Business, Innovation and Employment, and range from 1990 to 2011.
They show in that time, the population grew by 27% but energy use grew by just 16%.
The saving is attributed to several things, including improved consumer awareness and more efficient household appliances and transport.
The figures also show so-called energy intensity improved across most sectors.
This is a measurement of the amount of wealth that can be produced per unit of energy consumed.