D.—l

XV

The fact that the Wellington consumption does not show a commensurate increase with the others does not indicate that the consumption of electricity is not growing in Wellington. The reduced consumption of Mangahao power is due to the fact that the growth of load in other districts has necessitated an increasing use being made of the Wellington City steam plant. The peak load carried by the plant during the financial year was 18,100 kw., but during the past winter loads up to 20,040 kw. have been' carried. Very little trouble has been experienced with the power-station or headworks. On the main transmission-line to Khandallah, the main Wellington and Hutt Valley Substation, there were four interruptions during the year, the total duration of interruptions being only eleven minutes. Service over the lines to Hawke's Bay and Wairarapa was not quite so good particularly in the earlier portion of the year, where trouble was experienced owing to excessive swinging of the conductors during heavy gales. To remedy this, shutdowns were arranged on Sunday afternoons and times which would cause the least inconvenience to consumers. The modifications made to the line, and the installation of additional oil circuit-breakers, has very considerably reduced the number of interruptions, and also their duration.

Hydro-Electric Develop ment. Percentage earned on Operating Capital after paying all operating charges.

On the whole capital in operation in the Electric Supply Account 6-95 per cent, lias been earned after paying all operating and management expenses. CONSTRUCTION WORKS. Lake Coleridge. An expenditure of £171,618 has been made in connection with the duplication of the main generating plant, which was completed in the early portion of the year. The first 7,500 kw. unit of the new plant was put into operation at the end of July, and the second unit of similar size in December. The whole of the old low-tension switch-gear was replaced with new gear of the ironclad type to provide for the increased capacity of the station. This work had to be carried out step by step while the plant was in operation, and was completed without any interruption to the supply. Similar new switch-gear has been installed in the main Addington Substation where again the work had to be done without interrupting supply to our various consumers.