Post-quake Christchurch is continuing its love affair with diesel fuel, the latest energy-consumption figures show.

Growth in demand for diesel, rather than petrol, is believed to be a result of the extra heavy machinery and generators being used in central-city demolition work.

Christchurch Agency for Energy statistics released this week cover the 12 months from March 2011.

The agency has also calculated what it calls "earthquake impact" consumption figures for the year from February 2011. In that period overall energy use dropped 4 per cent compared with pre-February 2011 consumption.

Diesel use was up 6.5 per cent, while petrol sales were down 5.8 per cent and electricity use dropped 9.2 per cent.

For the March 2011 to March 2012 period, energy consumption fell 2.2 per cent compared with pre-quake figures.

Annual use of diesel was up by 6.5 per cent, but electricity use fell 6.9 per cent and petrol use was down 3.8 per cent.

Figures for the latest quarter available - January to March this year - show a slight turnaround compared with the same quarter in 2011, with a 5 per cent increase in overall energy consumption.

Diesel sales were up 6.5 per cent, with 2.2 per cent and 3.2 per cent rises in electricity use and petrol consumption.

Agency acting chief executive Merv Altments said given the expected timeframe for the city's recovery, the trends were likely to continue.

"There's a lot of contractor activity in town still going on, with cranes and trucks taking material away," he said.

"It's got to have an impact on the usage of diesel as none of that activity would normally be happening.

"When we launched the energy database, we said use was likely to return to pre-earthquakes levels of energy consumption gradually, and the figures support this.

"We're still not clear what the final mix of energy use will be, but the Christchurch deconstruction and rebuild . . . may result in long-term energy-use changes."

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