Mokau coalfield assessed

Press, 11 April 1984, Page 26

Mokau coalfield assessed

PA Wellington The Mokau coalfield in the King Country could supply about two million tonnes of coal a year for a North Island thermal power station, according to a report released.

The Minister of Energy, Mr Birch, said although it was still the Government’s intention to use coal from the Maramarua field in the Waikato for the next thermal power station, “investigations on the Mokau coalfield show Mokau coal could be used instead.” Mr Birch was commenting on a Mines Division report, “Mokau Coalfield Energy Development,” which he released yesterday. The report outlines investigations done so far.

The 1983 energy plan proposed that a 500 megawatt thermal power station, the

first stage of a 1000 megawatt station, be built in the North Island with first power available about 1995, the report said. Feasibility studies so far had concentrated on the Maramarua field as the fuel supply for the 500 MW station.

However, the report said it now was proposed to proceed with investigating mining, power station and infrastructure requirements for the possible development of the Mokau development as another option.

An interim mining feasibility study completed in December, 1982, estimated coal extraction costs from the mine at $3B a tonne. When the costs of a new township, land purchase, coal rights purchase and preparation were included and prices updated to November, 1983, the over-all

coal cost at a 10 per cent real rate of return was in the order of $5O a tonne. Nearly 100 million tonnes of “in situ” reserves were estimated to be contained in five seams with nearly 74 million tonnes estimated to be recoverable. The study had shown there was sufficient extractable coal to cover the 30 year life of a 1000 MW power station. Mr Birch said that if the coalfield was fully developed to supply coal, the extraction rate, at about two million tonnes per annum, would make it one of the biggest coal projects in the country. The costs for electricity generated by Mokau coal were similar to those estimated from Maramarua coal when all development and transmission requirements were considered.

The development of the Mokau coalfield together with the construction of a second thermal power station would have a “major impact” on the King Country region and possibly in Taranaki, he said. “A permanent workforce of more than 1000 and a similar number of additional houses would be needed, if both projects went ahead next decade. “The many millions of dollars spent would have a major impact on the economy of the region.” Mr Birch said investigations on the coalfield were necessary as two-thirds of the present growth in electricity usage was occurring in the North Island. “Natural resources for power production in the North Island are sparse and those that are known, such as the Mokau field, must be proven so that adequate

planning for future production can be undertaken,” he said. Drilling since December, 1982, had increased knowledge of the coal and a new geological interpretation for the areas to be mined by underground methods was required. A survey of the existing environmental data was also being done. This would be used in a preliminary assessment of mining and environmental constraints due to be completed this year. A full mining feasibility study will then be done, examining all aspects of a mining development. The developer had not yet been decided though State Coal Mines, private enterprise or a combination of both could be considered, he said. The mining study would define the best way of mining the coal in the national interest.