ELECTRIC POWER SUPPLY

Poverty Bay Herald, Volume LXIV, Issue 19371, 8 July 1937, Page 6

ELECTRIC POWER SUPPLY

INCREASE IN DEMAND SOUTH ISLAND SCHEMES EXTENSIONS PLANNED (Special to the Herald.) WELLINGTON, this. day. The growth in the demand for hydoelectric power in New Zealand is almost phenomenal. The engineers who control the big State system are not prone to use a phrase of this kind, but the graphs demonstrating the maximum demands through the years clearly prove the point, and now demonstrate the necessity for considering the provision of further generating units for the Waitaki power plant. This question is being brought before the Cabinet by the Hon. R. Semple, the Minister of Public Works, in good time to meet the demand which is building up to the point suggesting that the increased supply will be required when the units are at work. Construction of generators and turbines takes many months, and meanwhile the demand for power grows rapidly in the South Island.

In 1934, when the Lake Coleridge scheme was the sole State undertaking in the South Island, the maximum demand load was 32,500 kilowatts. In the following year, when the Waitaki undertaking commenced to supply power, the maximum demand carried by the joint system rose to 36,800 kilowatts, with a brief rise to 40,000 kilowatts when Dunedin City required power from the State lines owing to a temporary breakdown at Waipori.. The demand continued to grow rapidly, and the 1936 miximum was 44,000 kilowatts supplied jointly from Coleridge and Waitaki. Acquisition by State

The acquisition by the Government of the Southland Power Board’s scheme including the Monowai generating plant increased the capacity of the South Island system by 5500 kilowatts, and this section, not yet connected with the main system, is seriously. overloaded.

The maximum demand for the South Island hydro-electric system in 1937 reached 57,000 kilowatts. The generating capacity of Coleridge is 34,000 kilowatts, and that of Waitaki at its present stage, 30,000 kilowatts, so that the market for power is closely approaching the existing capacity to provide it without overload. With two important generating systems connected in the South Island, the engineers have made Coleridge a good reserve for power supply in case of emergency, The lake is a good holding ground, but its level drops under conditions of high demand. This station can be operated on a range of 10ft. in water level of the lake, but bringing in the Waitaki scheme, the department has been able to conserve. Colcrigc water and keep up the lake level in case of.exceptional calls on its generating system. Running' at Capacity

The Waitaki plant has therefore been running at full capacity, with its two units each generating 15,000 kilowatts.

The Monowai plant serving Southland is receiving power from the Invercargill steam generating station owing to the heavy load, and in due course, with the.'completion of an inter-connecting power line which will enable Waitaki current to be picked up at Gore, the Southland requirements will be fully met. I - •

However, at the northern end of the system there is overloading on the West" Coast, and a transmission line is being built to take the WaitakiColeridge power into that area, the Diesel plant formerly at Lyttelton being erected on the West Coast as a temporary reinforcement of the supply, The department anticipates a great increase in power demand from this area, for it has already signed contracts to supply power to three large gold dredges, each taking about 1000 kilowatts, and it is negotiating to supply other dredging plants which are contemplated..-.',.-: