More Cook Strait cables required if dam proceeds

Press, 6 November 1986, Page 6

More Cook Strait cables required if dam proceeds

PA Dunedin Duplication of the Cook Strait power cables is crucial to the future of the Clutha Valley Development and the Luggate dam if electricity generated in Otago is not to be wasted, said the Ministry of Energy yesterday. Water from both Clyde and Luggate would have to be spilled unless extra capacity was available to send electricity north, they said.

The officials were elaborating on comments by the chairman of the Electricity Corporation Establishment Board, Mr John Fernyhough, who said, the Luggate dam go-ahead was a $L billion decision rather than just approval to start a $240 million construction programme.

Central to the decision was expansion of the Cook Strait cable link — and the most recent estimate

of that was $7OO million to $750 minion.

The Electricity Division’s assistant. general manager for development, Mr Stan Wong, said even some Clyde dam-gener-ated electricity would normally be surplus to requirements for the first. two years of its life, mainly because of the restricted capacity of the existing cables. The potential to generate up to 1000 gigawatt hours of electricity would be lost because water would be spilled over the dam for 1989 and 1990 at least

Only in a “dry” year would there be no spillage in Clyde’s first two years, after which natural growth in the economy would match demand with supply. If Luggate went ahead as planned, and was commissioned by 1994, the electricity generated would be surplus unless a

new user was found in the South Island, or additional capacity could be built into the cables in time. One of the three'existing Cook Strait cables was faulty, and the remaining cables were considered to be suspect The 1984 Energy Plan argued the case for laying new ones, suggesting a programme, costing $l9O million in March, 1984, to increase capacity by 300 megawatts by 1991. Mr Wong said the plan was to create a 1000 megawatt link costing about $750 million. This would be with two cables and a third acting as a spare.

The Ministry of Works and Development’s chief power engineer, Mr Mike Williams, said he would need a decision within the next two months if work on Luggate were to start by April. The Electricity Division maintained there were

economic advantages in delaying the Qutha Valley programme, starting with the Luggate dam, because of the decision to burn Maui gas in the North Island for electricity. The division needed time to plan the new cable link, and the breathing space should avoid creation of a surplus of electricity which would be wasted because it could not be transmitted north. Mr Williams, however, argued that cost could be less in real terms to start Luggate now than in 10 years. In spite of the Government caucus effort last week to have work start on Luggate before June, the Ministry of Energy officials were still adamant about the need to delay the programme. Mr Wong said they realised the delays in a Luggate decision were concerning people in the south, but he said the

division was faced with i several difficulties. The push for a Luggate deci- •! sion occurred in the middle of the transfer of policy-making from the Ministry to the Electricity Corporation. • The division’s general manager, Mr Kevin McCool, said an early Luggate decision would limit the corporation’s options and was “throwing a curly one” in the middle of departmental restructuring. The corporation was charged with applying market-led economic principles- to electricity production and to return a “profit” to the taxpayer. If the Luggate power scheme was delayed, redundancies on the Clyde dam site would start in the middle of next year, a ; Ministry of Works official said yesterday.