The
lignite resource in the southern part of the South Island is New
Zealand's largest source of indigenous primary
energy. The ten deposits evaluated by the Liquid Fuels Trust Board (LFTB) have a
total recoverable reserve of 6.2 billion tones equivalent to 74 000 PJ of energy
or 20 times the original energy content of the Maui gas field. Updating the
economics of the original LFTB studies indicates that lignite could be mined for
between NZ$1.0 and 3.0/GJ. Its conversion to synthesis gas for production of
petroleum products, chemical methanol, ammonia/urea fertiliser or electricity
would be in the national benefit and likely to be commercially economic at
today's product prices.