ELECTRIC WATER HEATERS

Taranaki Daily News, 16 June 1930, Page 12

ELECTRIC WATER HEATERS

ARE THEY A PAYABLE LOAD? REPORT TO THE OPUNAKE BOARD. The- question of whether'or not the electric water heaters that had been •installed on the system were payable or were a drag by consuming power at a non-payable rate that'could be more profitably used in other directions, particularly during \ the period when there was a scarcity of current, has exercised the minds of members of the Opunake Power Board for some time, and on the suggestion of Mr. Chambers the board decided to secure a report on the subject. This report was submitted at yesterday’s meeting by the secretary, Mr. J. N. Stephenson, after collaboration with the engineer, Mr. S. Fraser. It showed that heaters were not the bugbear that they were consid-

ered to be by some. The question of electric water heating: has always been a difficult problem for power boards, not only from the electrical but'also from the financial

aspect, said the report. Whilst this board’s charges for water heater elements may appear to be low as compared with other classes of power, there are several features regarding supply to heaters which require to be borne in mind.

In the first place the board permitted water heaters to be installed with an unrestricted supply which, as events have transpired, was inadvisable, but the fact remains that they were encouraged in view of the .fact that at that time the board had power to spare. A charge of £6 per annum, or«£4 10s per annum if operated on a two-way switch from an electric motor, was made, and a large number of the present consumers were induced to instal heaters in view of the fact that this charge was considered a fair one.

The installation of a great number of domestic water heaters is absolutely necessary to encourage the installation of stoves, which represent a very prolific source of revenue for the board. It is practically impossible for a consumer .to instal a stove unless a water heater can be installed also, and as the stove, load is about the only one which can be developed to any extent in this board’s district, it would appear inadvisable to make the charge for water heaters too heavy. Farm water heaters are not so important as they are not an absolute necessity to the milking motor consumer. Domestic water heaters are certainly liable to be on during .peak hours but'in the case of this board thia is not such a serious matter as would be - the case if the board were buying power on maximum demand. Raising the charge will not tend to keep 'domestic heaters off during peak load hours; time switches alone can achieve that purpose. The board is, in.numerous cases, not able to supply continuously an efficient supply, as during dry spells the supply is off altogether during night hours, water heater consumers being the only ones affected thereby, and in the past the board hast not hesitated to disconnect altogether water heaters in cast of shortage of power.

Although water heaters are not favourably regarded by. supply a ut b° ritie3 as being an ideal load,'they are recognised as being necessary to encourage the use of other and better revenue producing appliances. The capacity of a water heater is about i k.w., or equal to ten ordinary metal filament lamps, so that it will be seen that the capacity is not as greaJt- as is generally considered.

One objection to the water heater load has been that it affects the board’s water storage during night hours. This may be so, but in the first place water heater? were originally intended more as a . night load than a day load and, secondly, the fact of a reduction of Jd per unit for bulk supply during night hours having been secured should considerably improve the financial position regarding these heaters. A comparison of returns per kilowatt of connected load of the various classes of power may prove interesting, and I set out hereunder a table showing same, as applied to the board’s system. The figures given are average figures: — 'Stoves £8 0 0 per annum

Milking motors . £lO 0 0 per annum Factory motors . £lO 0 0 per annum Water heaters .. £lO 0-0 per annum From . the above figures it will be seen that the financial return for water heaters favourably with the return from other classes of power. The main disadvantage appears to be that they are practically continuous consumers, but if this service was restricted it would be of no use for water heating Revenue earned from water heaters for the last financial year was £663 10s 9d, or l-3d per unit, or £lO per kilowatt of connected load. An analysis of water heaters connected to the system is as follows: —Domestic with stove 49, without stove 18, farm, with motor 61, without motor 3; total, 131. The report advised the board that it would be prejudicial to the board’s interests to raise the charge for water heaters, but suggested that charges be altered to £1 per 109 watts per annum and 15s per 100 watts per annum for domestic and farm water heaters respectively. Mr. Chambers said that figures could be made to say anything, but he could not quite understand them. For instances factory and milking motors were given at .£lO per annum per kilowatt, the same as water heaters, so that it appeared as though each produced'only gd per unit. The secretary said that a water heater was consuming all the time, whereas a motor was running only a portion

of the time and therefore worked out at, say, 2d per unit. The total connected load of the board’s system was 1500 kilowatts and the water heaters represented 60 or 70 pet cent. He pointed out that the proposed increase would not affect the ordinary water heaters at present in use. Mr. Chambers said that he was responsible for the report being brought down, but in view of what it contained he did not favour any alteration being made. Mr. Tosland said the public were opposed to any increase in price, but desired'to be supplied with more power. The chairman said the report was educative. Water heaters had been a bugbear to the board, but now they knew just where they stood. Mr. Chambers said the report had set at rest any fretfulness regarding water heaters being a heavy drag on the board’s power.