ROXBURGH MAY SUPPLY ALUMINIUM PROJECT

Press, Volume XCIX, Issue 29336, 15 October 1960, Page 15

ROXBURGH MAY SUPPLY ALUMINIUM PROJECT

"The Press" Special Service

DUNEDIN, October 14.

The supply of electric power from State sources offered to the Consolidated Zinc Corporation to speed the initial operation of an aluminium processing plant in Southland probably will be mainly Roxburgh power from the Clutha river rather than from Benmore.

The survey of a route for a high tension transmission line from Roxburgh direct to Invercargill is being made by the New Zealand Electricity Department, and construction, according to the department, is expected to begin early next year. The line is scheduled to come into use before the winter of 1963.

A basic concept of power transmission economics is that the user should be as close as possible to the point of generation. In other words, power for a major user should come direct from th? closest supply point which will satisfy its demands.

The situation in the South Island is complicated by the exist-

ence of the grid—a series of transmission lines which to all intents and purposes circle the island, connecting up all State generating stations. The fundamental principle of direct supply still holds good, in spite of the grid’s tendency to pool supplies from all generating stations. \ Capacity By 1962 By the end of 1962 Roxburgh is scheduled to be up to its full designed capacity of 320,000 kilowatts, which should be ample to satisfy the needs of an aluminium industry—in its initial stages at least. By the time power is wanted for a possible aluminium smelting plant the normal domestic and industrial use of power in the South Island will have grown, and if the output of the Clutha station is to be used to any major extent in Southland, additional generating capacity will have to be brought in. It seems likely that'the role of Benmore when it starts to produce will mainly be to shoulder Roxburgh’s normal load and meet the growth of demand north of Dunedin. The decision to install an added 220kv transmission line to Invercargill was made more than 12 months ago in anticipation of normal growth of demand in Southland. The present plans are for its completion about a year after the full commission of the Roxburgh station. The line will be about 80 miles long. It will follow the Clutha Valley as far as Ettrick before rising into high country and emerging in Southland inland of Gore. From there it will extend direct to Invercargill.