Electricity use in Christchurch dropped 15% after the earthquake in February.
Overall energy consumption, including electricity, petrol and other fuels, decreased by just over 8% in Christchurch.
The figures are from the Christchurch Agency for Energy, an organisation set up Christchurch City Council and supported by energy companies.
Chief executive Merv Altments says the return to pre-earthquake levels of consumption is proving to be very gradual.
The agency says the reconstruction of the central business district in Christchurch provides a once in a lifetime opportunity to build a city using more renewable and energy efficient options.