POWER POTENTIALITIES

Sun (Auckland), Volume IV, Issue 935, 31 March 1930, Page 10

POWER POTENTIALITIES

LINKS REVIEWED FOR WAITEMATA BOARD NO EXTENSION FAVOURED Comprehensive reports reviewing proposals to link the east coast and the west circuits in the Waitemata Electric-Power Board's district, and possibi ties in an extension of the boa-d’s line from Silverdale to Waiwera and beyond, were brought before the board this morning. Extensions were not recommended. Both reports were mg - :nv further discussion will be by the board's general purposes committee The “east and west” and the “nv>~th and south” committees were recently set up by the board to review the system operated at present, and c *Vtain developments suggested. These committees carried out exhaustive investigations and met iring January, February and March. Questions reviewed by the east and west committee, it-s chairman, Mr. S. E. Kennings reported, were the advisability of connecting the board’s mains between the east and the west circuits, the annual saving in power costs by supplying part of the west coast from Takapuna substation, or vice versa; the probable load and the potential development on the Albany, Dairy Flat and Wainui. the Deep Creek. Silverdale and Wainui, and the Albany. Riverhead and Kumeu routes: and the capital cost involved. It was found that the main areas served were divided in a natural manner by the upper reaches of the Waitemata Harbour. From the supply centres at Henderson and Takapuna, the board’s reticulation radiated, each system, however, on the 11,000-volt side, remaining separate. The country in a northerly direction had been narrowed and the possibility of advantage from a connected system presented itself. The east and the west circuits could he connected by two routes—• from Albany via Dairy Flat, Massey Road and White Hills, or from Albany to Riverhead. On the first route, the country was expected to become productive and it was more satisfactory from a technical view, as the Kaukapakapa district would be brought nearer the main substatiou. On the other route, a bigger block than would be economically justified would be involved. HIGH LOAD FACTORS The question of a loop line along the first route was considered. The loctd factors at Henderson and Takapuna were particularly high, and, apart from seasonal and hourly diversity, any transfer of Joad in either direction could not improve this aspect materially. With increasing loatjs, the time might come when a line would have to be constructed from Takapuna to give sufficient supply to the northern districts. The voltage in Henderson district was satisfactory at the moment. Continuity of supply in relation to the interconnection was considered. To be of use, interconnection would have to be automatic, and the cost would not be justified. It was probable that savings, owing to diversity, would be negatived should suppiv points be changed during a Government quarter. On the basis of improved diversity, a saving of 100 k.v.a., or £SOO to £I,OOO yearly, could be expected were Takapuna and Henderson loads supplied from one point. From canvasses, it was apparent that many settlers were not in a position to take supply. It was found that an 11,000-volt line from Takapuna to th eKaukapakapa mains could not carry the Helensville town and country load. The engineer, Mr. F. J. H. Wilson, prepared alternative estimates for an 11,000-volt line from Albany, via Massey Road, to Kahikatea Flats Road, Kaukapakapa, and a 33,000-volt line from Takapuna to Helensville. On the first of these, a capital expenditure of £5,430, with an annual return of £306, was expected; on the second, with alteration to the existing 11-000 volt lines and to the 11,000-volt transformers at Kaukapakapa and Helensville there would be a capital expenditure of £12,980 for a return of £426 yearly. The committee believed that, under all circumstances, the construction of a loop line was not justified at the moment. It was not able to recommend an extension to supply he Silverdale area.. NORTH OF WAIWERA The extension of the board’s lines from Silverdale to Waiwera and beyond, the probable development of the district, and the guarantees needed from Whangaparaoa, Orewa, Waiwera and Puhoi were considered by the north and south committee, with Mr. J. W. Hayden as chairman. The nearest transmission line was about six and a-half miles from Silverdale, and the cost of bridging the gap had not been considered. The meagre settlement in the area surprised the committee’s members. After inspection of the area immediately north of Waiwera, the committee considered it unlikely that the board would be requested to supply electriicty in these districts. A transmission of 33,009 volts would be necessary and would not be justified, on the score of cost. On the Whangaparaoa Peninsula it was estimated that there would te about 50 residents, mostly in summer cottages. After reviewing estimates prepared by Mr. Wilson on extensions from Silverdale to Red Beach, Arkle’s Bay and Manly, Orewa. and Orewa to Waiwera, the committee could not recommend the extensions. It was thought probable tL l a route along the Wai-nul-Upper Waiwera Road would, at a future date, prove the most suitable and payable approach.