WAIPORI AND WAITAKI

Evening Star, Issue 22451, 23 September 1936, Page 9

WAIPORI AND WAITAKI

VALUE DF INTERCONNECTION REPORT OF ELECTRICAL ENGINEER The value of the interconnection of large capacity power stations such as Waipori and Waitaki is stressed by the city electrical engineer (Mr M. C. Henderson) in his annual report to the City Council, The year that ended on March 31 proved to be a marked contrast to the one that preceded it, from an operating point of view (states the engineer). Whereas 1934-35 had been as nearly perfect as could be hoped for when all the circumstances are taken into account, last year provided emergencies which would have proved much more serious than they actually turned out to be had it not been for the fact referred to briefly in last year’s report that Waipori power station had at length been linked up with the new Government hydro station at Waitaki.

For 28 years Waipori had carried on independently, and although in that long period of years serious mishaps had been encountered, and _ others much more serious had been missed as by a miracle, the record for reliability was remarkably good, which is borne out by the fact that only a negligible number of consumers, who depended entirely upon Waipori for their power supply, thought it necessary to provide any auxiliary plant for use in case of emergency. The experience of supply authorities in other countries showed conclusively that interconnection of power plants provided many important advantages, and the decision of the punedin City Council to link up with 'the new Government station at Waitaki, as soon as it was ready for operation, has already been completely justified. On two occasions within the past year supply would have failed completely over the whole Waipori system for nine hours and four hours respectively, if Waitaki had not been available. In the first case the inconvenience caused to consumers was very brief, and affected only a few in number, while on the second occasion the change-over to Waitaki was made in a few minutes, with a minimum of disorganisation, in the former case, a tire had been lit by a shepherd about half a mile from the transmission lines on the top of Maungatua to burn some scrub; the wind changed suddenly and increased to a gale, which swept the tire right along the lines for several hundred yards, and the fierce heat and sparks set tire to a few poles in all three lines, so that each failed in turn until Waipori was completely isolated from the city. The whole of the load was thrown on Waitaki, which carried on for nine hours, until two of the lines had been repaired, this work being hampered by a snow storm. On the second occasion, a short-cir-cuit occurred on the extra high tension busbar at Waipori, and repairs could not be affected with safety without shutting down the station. Once again Waitaki carried the whole load for nearly four hours. Measures have been taken to prevent the possibility of a recurrence of these mishaps, but their occurrence illustrates the value of the interconnection of large capacity power stations. The two power stations have now been electrically interconnected for nearly five months, and in spite of the fact that they are located about 160 miles apart, they run in parallel remarkably well. It was expected that the control of the load that is carried by Waitaki in terms of the agreement between the department and the Government would present some new and difficult problems, and so it has proved. Some of these have already been solved satisfactorily. and the' others are being dealt with in the confidence that they in time will also be overcome.