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New Zealand's self-sufficiency in oil more than doubled last year, due to the offshore Tui field coming on stream and greater production from the Pohokura project in Taranaki.
In 2006 the country was 14 per cent self-sufficient but this climbed to 32 per cent last year, still down
from a peak of 55 per cent in 1997, according to Ministry of Economic Development figures.
Around the time of the 1974 oil shock the country was just 4 per cent self-sufficient, calculated as domestic oil production divided by total domestic consumption.
Use of petroleum products climbed by 1 per cent last year. Petrol and diesel dominate fuel consumption, accounting for 44 per cent and 42 per cent respectively
The ministry report says oil and condensate reserves jumped 53 per cent last year. Estimates of remaining reserves in the country's producing oil fields rose to 148.3 million barrels at January 1, from 97.1 million barrels a year earlier.
Tui, which started production a year ago, accounted for about 35 million barrels of the increase. Its total reserves have since been upgraded to 50.1 million barrels by operator Australian Worldwide Exploration.
Reserves remaining in the offshore Pohokura field, owned by Shell, OMV, and Wellington's Todd Energy, increased 30 per cent to 55.9 million barrels. Liquid reserves in the partners' Maui field rose 9 per cent to 24.1 million barrels.
Gas reserves increased 10 per cent to 2.03 trillion cu ft, driven by a 16 per cent gain at Pohokura to 908 billion cu ft and a 13 per cent improvement at Maui to 439 billion cu ft.
The figures show that total energy used by consumers grew by 1 per cent between 2006 and 2007.
Since 1990 the economy has outstripped that rate of energy use.
This represents an improvement of energy efficiency of almost 15 per cent.
In the same period energy use per person grew by 10 per cent. New Zealanders' annual energy demand was equivalent to approximately 3400 litres of petrol per person last year.
Average electricity prices increased by 3.2 per cent after price falls the previous year.
Generation from non-renewable energy sources (fossil fuels and waste heat) was 1 per cent less in 2007 than in 2006.
While coal-fired generation was sharply down, gas was up by 21.9 per cent.
Wind energy, which accounted for 2.2 per cent of total electricity generation, almost doubled from 2006.
Total wind capacity increased by 88 per cent to 322MW by the end of 2007.
New Zealand Wind Energy Association chief executive Fraser Clark said greater wind generation would help to keep electricity prices down as the cost of thermal generation rose.
"The cost of wind generation is not affected by the increasing price of fossil fuels or the cost of carbon emissions."