POWER CABLE ACROSS COOK STRAIT

Press, Volume XCIII, Issue 27907, 2 March 1956, Page 10

POWER CABLE ACROSS COOK STRAIT

Government Seeks Report On Practicability

INQUIRY TO BE COMPLETED TfflS YEAR (New Zealand. Press Association) WELLINGTON, March 1. The Government proposes to investigate immediately the practicability of linking the North and South Island power systems by a submarine cable across Cook Strait. An offer by British Insulated Callenders Cables, Ltd., to conduct the investigation has been accepted by the Government. The company has undertaken to complete the investigation by the end of this year.

The Minister in charge of the State Hydro-electric Department (Mr W. S. Goosman), making this announcement today, said that the country’s future power programme depended on whether a link was practicable.

“The power demands of New Zealand are great, and the time we have for making the decision is short, ’ said the Minister. “Are we to build more power stations in the North Island, or are we to build them in the South? The answer to this question can be given only after a report on a specific proposition to interchange electricity by submarine cables linking the two islands.”

Mr Goosman said that the investigators would consider the economics of supplying power for the North Island from South Island stations compared with other means of supply, and also the time factor—at what date the link would need to be completed. Power from the South Island would not be required until the North Island demand exceeded the present and planned North Island supply. “The combined capacity of existing power stations and of those under construction in the North Island is 1,153,000 kilowatts,” said Mr Goosman. According to the estimated figures of the combined committee on North Island power supply, the demand would exceed that total by 1962-63. “It is at that stage that a case exists for obtaining hydro power from the South Island,” he said. “The remaining hydro-electric potential in the North Island that could be developed economically will be relatively small, and the only other practicable method of power production in the North Island would be steam stations using coal, oil, or nucleajj fuel, and geothermal steam stations,” said Mr Goosman. Estimated Demand

“In the 10-year period between 1962 and 1972 the North Island power system’s peak load, it is estimated, will increase from 1.180,000 kilowatts in 1962-63 to 2,163.000 kilowatts in 197273. an increase in round figures of 1,000,000 kilowatts. During this 10year period the installed generating capacity must be increased by an equal amount, that is, by 1,000,000 kilowatts.

“The increase in generating capacity would be equal to approximately one and one half times the total existing generating capacity in the North Island which has been installed over th? last 40 years. The capital cost of the new power stations alone would be of the order of £75,000,000 to £150.000,000, depending on the type of station to be used.

“The output of the additional generating stations during the 10-year period 1962-1972 would amount to about 24.000 millions of kilowatt hours, and at the end of the period the output would be approximately 5000 millions of kilowatt hours a year,” he said.

“I have a report from the department which summarises the magnitude of the North Island power problem as follows: New power stations to be commissioned between 1962 and 1972, 1,000.000 kilowatts; output of these* stations 1962-72, 24,000 millions of kilowatt hours; capital cost of new stations, minimum £75,000,000, maximum £150,000,000; cost of power production from new stations 1962-72. minimum £40,000.000, maximum £100,000.000; cost of power production from new stations a year at 1972. minimum £8,300,000, maximum £20.800,000. “The maximum and minimum costs I have quoted depend on the type or types of power stations to be used,” said the Minister. Coal-fired Stations

“For the coal-fired steam stations of 1.000,000 kilowatt capacity the amount of coal required would be about 2.750,000 tons a year at a cost of about £7,500,000 a year, if obtainable. For oil-fired stations of the same capacity the amount of oil to be imported a year would be about 1.500,000 tons at a cost of about £13,000,000.

“For steam stations using nuclear fuel, the capital cost would greatly

exceed, probably by at least 50 per cent., that for coal or oil-fired steam stations or for hydro stations. “The cost of power production by nuclear power stations would be at least 25 oer cent, greater than by hydro stations. “If geothermal steam stations were to provide the whole of the 1.000.000 kilowatts, the amount of geothermal steam required would be about 15 times the amount that is to be initially produced at Wairakei. It is not considered to be within the bounds of possibility that this amount of geothermal power could be developed by 1979.” The North Island-South Island link was the remaining method by which the North Island's future demands could be met. said the Minister. If Cook Strait did not exist there was no cuestion that producing power in South Island hydro stations would be the most economic method of supplying the 1.000.000 kilowatt* that would be required to meet the future North Island need.

“Compared with coal-fired steam stations, the capital cost of hydro stations would be about the same, but largely because of the saving in fuel costs, the annual cost of power production in 1972 would be about £8.000,000 less,” Mr Goosman said

“Compared with nuclear power stations. the capital cost of hydro stations would be very much less, possibly to the extent of £75.000.000. and the annual cost of power production in 1972 would be about £12.000.000 less.

‘‘lt is clearly our duty to see whether transmission of power across Cook Strait could be accomplished satisfactorily and at reasonable cost.” Economic Implications

Mr Goosman said that the high cost of the transmission of electric power from hydro stations in the South Island would be offset by the lesser cost of the hydro-electric stations in the South Island.

“It is estimated that the capital cost of the high-voltage transmission lines and of the submarine power cables would be about 50 per cent, of the capital cost of the hydro power stations. or about twice the comparable cost of transmission from the Waikato stations to the southern half of the North Island,” he said. “Nevertheless the over-all cost of hydro power at Wellington from the South Island would be less than the cost of similar power from the later Waikato stations such as Whakamaru. Waipapa, Atiarnuri, and Ohokuri. The extra cost of transmission is more than offset by the lesser cost of the hydro-electric stations in the South Island. “Likewise, under these conditions it can be said that the delivered cost of power from the South Island to the southern half of the North Island would be about half the delivered cost of power from coal-fired steam stations on the Waikato coalfields, and less than half the cost of power from nuclear power stations in the Wellington province.

“The saving a year to New Zealand in 1972 of producing power for the North Island by hydro stations in the South Island and transmitting this power by high-voltage transmission lines and submarine power cables, compared with producing the same amount of power by nuclear power stations in the North Island, might be about £10.000.000.

“The saving in subsequent years for larger amounts of power could be very much greater,” said Mr Goosman.