TE KUITI'S LIGHTING PROPOSALS.

King Country Chronicle, Volume VI, Issue 415, 18 November 1911, Page 6

TE KUITI'S LIGHTING PROPOSALS.

EXPERT'S REPORT.

SYSTEMS COMPARED. GENERAL. Owing to the undulating formation of the land at the outskirts of the borough providing ideal knolls for residences, Te Kuiti has its population somewhat more scattered than is usually the case in boroughs of an equal number of inhabitants, yet while these building sites lend themsevles to desirably inducing the construction of dwellings out of the business area of the borough, they remove from proximity to a central supply station or works, desirable consumers, for by the appearance of the houses situated there, there would be a demand for light and heat. To bring these consumers into the scope of reticulation means a heavy expenditure in mains in the initial cost of any scheme. Making the area catered for large in the first instance, although increasing the initial outlay would more than proportionately decrease the otherwise neccessary annual expenditure in extending mains, and also obviating the necessity of constantly having the roads uprooted. Considering that a large number of the vacant sections in the borough are leasehold it is reasonable to expect a rapid increase of the number of buildings, although for a basis we have estimated the probable number of consumers at 12*5 the mains as laid down could supply three times the number; therefore there would be practically no extension of any moment required for two or three years, unless some of the entirely vacant blocks should become rapidly covered with buildings.

The central station or works should be situated off the main street as indicated on the plan, as this position would give an even distriniuion on medium length mains, in regard to electricity this is an important factor as there is a considerable loss of voltage on long circuits. Street Lighting.—As indicated we have allowed for twenty-seven 50 C.P. lamps and to avoid the cost of a meter at each lamp we would advise adopting an annua! rate per lamp. The lighting and extinguishing of the street lamplights should be controlled from the Central Works, for gas by the "wave" or any similar system. Electricity would require the iamps off a special circuit and controlled by switches on main board, the reason for control is that the lights may be extinguished at, say, 11 p.m., re-lit and extinguished 45 minutes before and after train time in the morning.

Consumption.—raking an average of results as obtained in other towns we estimate the consumption per consumer per month for—Coal gas at 2000 cubic feet, electricity at 12.5 units. Waipukurau gives a result of 2,333,H00 cubic feet sold to an average of 105 consumers for six months, equalling 2116 per consumer per month for petrol gas. It is reasonable to assume that Te Kuiti with its night trains necessitating the lighting of railway station, boarding and other houses at hours when other towns are in darkness will create a higher average. Premises at present lighted by aerogene acetylene or other gas having the necessary pipes in would be at very little expense in connecting up to a town supply of either petrol or coal gas. In our estimate for annual expenditure we have allowed an item of £25 to cover the cost of work in the town clerk's office in attending to lighting account.

Initial Costs.—ln these we have allowed £SO for expenses in taking a poll which may or may not be exceeded.

Depreciation at 21 per cent may appear low for the gas systems, however, with a recurring allowance for repairs and maintenance, we think it adequate, especially as these systems are not subject to frictional wear as in the case with electric generators. The greatest depreciation in coal gas is with the retorts, these require renewing in small installations properly worked about ence in five years and cost £9 each and £3 for getting, our estimate includes a 3-2 retort bench.

Depreciation on electrical plant is high owing to all portions being subject to frictional wear and the efficient life of a set of accumulators being about seven years, this portion is valued at £4OO. Power maintenance is also high as the producers require periodically relining, slack in bearings, etc., attended to and the overhead mair.s subject to stress of weather.

Charge for Supply to Consumers.— We have in each instance taken a rate at which it is reasonable to assume the supply can be sold, showing a small profit on expenditure and to give an idea to consumers as to their prospective account. Naturally the average consumption is greatly in excess of the requirements of the small householder who may use less than 1000 cubic feet of gas or 6.5 units per month, the average being brought up by hal!3, boarding houses, stables, etc., We have only considered power users in the case of coal gas for it is self-evident that an ordinary benzine engine would be more economical than either petrol ga3 or electricity at the rate.3 required to pay cost of production. ESTIMATED COST OF SYSTEMS. PETROL GAS. £. a. d. Buildings, plant, reticulation, street lamps and 125 connections ... 3250 0 0 Cost of poll ... 50 0 0 Engineering, supervision and sundry initial expenses ... 200 0 0

COAL GAS. Building, plant, reticulation, street lamps and 125 connections ... 6200 0 0 Cost of poll ... 50 0 0 Engineering, supervision and sundry initial expenses ... 250 0 0 £6500 0 0 SUCTION GAS ELECTRICITY. Buildings, plant, street transmission wiring, street lamps and 150 connections ... 4SOO 0 0 Cost of poll ... 50 0 0 Engineering, supervision and sundry initial expenses ... 300 0 0 £5150 0 0 Plans and specifications for the third estimate being of a more comprehensive nature than are required for the gas propositions would be proportionately more expensive to compile.

Air or Petrol Gas. —Air or petrol gas is one of the newest and most efficient iilumanants lately brought into practical use for lighting towns of a limited number of inhabitants.

Petrol gas is almost a misnomer for with a perfect mixture only lA to 2 parts in a hundred are petrol the remaining 93 or 9SJ parts being air, which is responsible for the gas being inexpensive. The gas containing a maximum amount of oxygen in the air, is burnt without further oxygen requiring to be added ; this constitutes a safe element in the use of the gas, for should a leakage occur through any cause the gas escaping mixes with he attmospbere, at once becomes dissipated and too weak to explode even if a naked light is brought into ciose proximity of the leakage. Petrol gas is a perfectly healthy gas, does not affect decorations carbonise or vitiate the atmosphere. The light to the eyes is exceptionally pleasant and is less strain to the sight than either coal gas or electricity. While the gas cannot be rivalled for lighting it is somewhat handicapped as regards heating and power producing, the iowness of the percentage of petrol in the gas makes it at once evident that having no body of petrol trie quantity U3ed would be large in comparison with explosive gas3es. We would advise the installation of a plant capable of manufacturing 10,000 cubic feet of gas per hour and storing the gas in a 10,000 ft holder ; this would allow of the plan being operated by one man who would also attend to new connections, lamp cleaning and all other duties connected with the system. The manufacturing of the gas does not require a highly qualified man, therefore a saving is made on cost of output. If the duties of turncuck for water supply were also performed by the gas manager it would be preferable to employ a higher grade man at £2OO. per annum and divide his salary pro rata with the two departments. One important factor to be taken into consideration is that if the borough prefers to install the cheapest light and for the present pass the consideration for nower, petrol gas is undoubtedly the cheapest, and the gasometer and reticulation would be serviceable should coal gas be installed at some future date.

The foregoing particularly refers to petrol or naphtha gas as it has been proved under practical use and demonstration. As there are manufacturers of apparatus for producing petrol and oil gas under different systems, in the event of your calling tenders for this class of gas, stringent specifications covering cost and quantities of raw material, capability of storing, condensation, variations in pressure for corresponding specific gravities and influence on high level lighting, while a substantial bond should be entered into covering the satisfactory working of the plant for a definite period.

Such stipulations we consider necessary owing to the limited trial such gasses have so far been subjected to. although in fairness to the inventors of the Waipukurau plant we should add that after two years of actual use the consumers have expressed satisfaction with the gas installed in their borough. PETROL GAS. £ s. d. Estimated Cost ... 3500 0 0 Revenue. 3,000,000 cubic feet at 5a per 1000 ... 750 0 0 27 street lamps at £6 each ... 162- 0 0 £912 0 0 Expenditure. Interest at 5 per cent. ... 175 0 0 Sinking fund at 1 per cent. ... 35 0 0 Depreciation at 2\ per cent. ... 87 10 0 Maintenance ... 26 0 0 Manager's salary ... 150 0 0 Petrol or naptha ... 226 0 0 Oils and sundry ... 10 0 0 Office charges ... 25 0 0 Ground rent ... 50 0 0 £784 10 0 Credit balance ... 127 10 0 £912 0 0 COAL GAS. Although admittedly there are several disadvantages in connection with using coal gas there is no doubt that if a borough is large enough to face the initial coat or has nrospeots of procuring the required number of consumers coal gas will serve the residents [successfully and economically for light, power and heat whereas its rivals, petrol gas and electricity, are individualised as producers of light only on the economical basis.

Coal gas has the advantage of decreasing in cost at a greater rate than pro rata to the increase of production owing to reduction of stand by expenses in maintaining the heat of empty retorts being reduced and a higher percentage of coke gained. The principal objection to coal gas is the production of CO2 gas during combustion which is destructive to

the improved combustion obtained in modern burners, this objection is greatly reduced and need not be considered seriously when compared with general utility, if a dwelling is at all ventilated the gasses would not be injurious to health. Power.—ln a borough where small manufacturers are established requiring motive power from one to twenty horse-power, coal gas serves a demand and as will be seen from our comparative tables on a basis which is inducive to a fair consumption for gas engines. £ s. d. Estimated cost ... 6500 0 0 Revenue. 3,000,000 cubic feet at Ss per 1000 ... 1200 0 0 50 B.H.P. estimate for factory work 182,000 ft at 6s per 1000 ... 39 12 0 27 street "lamps at £6 per lamp ... 162 0 0 Coke. 50 tons at 25s per ton ... 62 10 0 Tar, 2500 o- a |lons at fid per gallon ... 62 10 0 £1526 12 0 Expenditure. Interest at 5 per cent ... 325 0 0 Sinking fund at 1 per cent ... 65 0 0 Depreciation at 2J per cent. ... 162 10 0 Maintenance ... 78 0 0 Wages ... 250 0 0 Coal ... 420 0 0 Oils and sundry ... 15 0 0 Office charges ... 25 0 0 Ground rent ... 50 0 0 Credit balance ... 136 2 0 £1526 12 0 ELECTRICITY.

Electric light is the popular lightIt is clean, convenient and safe; it can withstand jthe keen competition of the incandescent coal gas burner, and in no way damages fabrics, metal or gilt work in proximity to it. For lighting hotels, halls, stables, fac-

Tories, restaurants and all such places where the use of lucifers is dangerous it is especially suitable. The ease and small expense with which extensions and alterations can be effected is also one of its advantages.. The metallic filament lamps give a soft; light and eliminates the objection of the excessive orange rays shed by the carbon filament lamps Tiie ease with which a lamp ay be lighted or extinguished makes a safe installation but induces a high rate of consumption. Jt is regrettable that the current is not applicable to heating and power on a more economical basis (this we explain fully on our comparative page). We have estimated for a power house containing 2 sots of suction gas engines and electric generators of 18 and 36 KW at 220 volts, also a secondary battery or accumulators. The 26 KW machine to be the main set used for direct lighting - and charging the accumuatlors. It would be necessary to run the main generator such time as the maximum load is required and to charge accumulators for the morning hours when only the street lamps and an occasional light would be in use. The IS KW set to be available either as an assistant to the main generator or accumulators for short runs or such time as any repair may require to be effected on the large generator or accumulators, allowing such to be carried out without undue haste and more thoroughly. It may appear to be more beneficial to duplicate the 36 KW set which would certainly be desirable from a duplicate point of view but would possbily absorb a considerable amount of the profit in extra capital charges. Electricity—(Suction Gas Power! £ s. d. Estimated cost ... 5150 0 0 Revenue. 22,500 units at 9d per unit ... 843 15 0 30 street lamps at £6 per lamp ... 180 0 0 1023 15 0 Expenditure. Interest at 5 per cent. ... 257 10 0 Sinking fund at 1 per cent. ... 51 10 0 Depreciation at 5 per cent. ... 257 10 0 Maintenance ... 120 0 0 Manager ... 192 0 0 1 Fuel ... 50 0 0 j Oil, acid and sundries ... 40 0 0 Ground rent ... 25 0 O j Office charges ... 25 0 0 ] £lOlB 10 0 ; Credit balance ... 5 5 o £IO2B 15 0 !

Hydro Electric. —After inspecting the power available at the Lake and Mokau rivers, we are forced to the conclusion that neither of these "an compete with suction gas. The Lake proposal is impossible as there is not a constant flow of water at all approaching the required quantity to develope sufficient power. The Mokau falls could be harnessed, but the expenditure contingent upon the undertaking would involve an annual expenditure which would make the cost of current in excess of the rate at which it can be sold if power is obtained from a suction gas plant. At the time of inspection, subsequent to a dry spell of some weeks, the falls were discharging a volume of water equal to 100 horse-power and ample for lighting Te Kuiti.

The falls be ins situated at the head : of a gorge with sides of perpendieular : stone, great expense would be in- j curred by cutting a race or attaching j pipea to convey the water to a power - house, at the foot of the falls, about ; 200 yards down the. river where, the only ilnt piece of ground is available \ for a generating station. However, ■ to justify our decision we hereunder give an approximate cost of plant, etc. : ;

Intake and conducting water to power-house ... 1500 Turbine and 65 KW 3000 volt A.G. generator ... 450 Generator house and tail race... 150 Resident engineer's house ... 300 8 miles of transmisison wire ... 1600 Transformers, switch hoard and mains ... 2000

£6OOO To this must be added either as a right of purchase sum or annual rental— Cost of land required, cost of water rights, cost of rights for trans mission wire over private property, wages of engineer in charge of powerhouse and increase charges on increased expenditure. The wages of a competent engineer alone at the falls power-house would be four times the cost of fuel for a suction gas-power plant. Therefore, as the hydro-electric proposition from this source cannot compete with the system already detailed we have not put you to the trouble of ascertaining the cost of the land required, water rights, etc. COMPARATIVE. (Comparison of Lighting upon the rates we have based our estimates) s. d. A 50 candle-power incandescent light consuming petrol gas burning for 100 hours would consume 600 feet of gas at 5s per 1000, costs ... 3 0 A 50 candle-power incandescent light consuming coal gas burning for 100 hours would consume 500 feet of gas at 8s per 1000, costs ... 4 0 A 50 candle-power metallic filament lamp on electric current for 100 hours would consume 5000 watts or 5 units at 9d per unit, costs ... 3 9 POWER.

A well-constructed coal gas engine with gas of 700 B.T.U's calorific value, will give one horse-power on a consumption of 17 cubic feet per hour. However, to allow for poorer quality gas we shall assume 20 cubic feet per B.H.P. hour.

A 10 B.H.P. engine, running on a steady load for one hour would consume 200 cubic feet of gas, which at 8s ner 1000 would cost Is 7 l-sd, or 1.92 d per B.H.P. hour, at 6s per 1000 cubic feet 1.44 per B.H.P. hour A 10 B.H.P. engine, running similarly on petrol gas, would consume 75 cubic feet per B.H.P. as this amount of gas holds J-pint of naptha in suspension and l-pint equalling one 8.H.P., therefore the consumption would be 750 feet per hour, which, at 3s per 1000 cubic feet, would cost 2s 3d or 2£d per B.H.P. hour. Electric Motor. 1 unit equals 1000 watts, 1 B.H.P. equals 746 watts,it so follows that one unit is one and onethird B.H.P.

When the current is consumed by a motor, it is read before it enters the motor.therefore for 746 watts to equal a B.H. P. produced, the motor would need to run frictionless and without resistance of inerta. However, as this state is an impossibility, an amount of electrical current must be absorbed in overcoming these disabilities, effecting a loss of current calculated atß per cent, in large, and up to 25 in small motors.

For average results we will assume 15 per cent, loss, making 74(5 plus 112 —BSB watts per B.H.P. available from the motor; 858 x lU—BSBO watts or 8580 units consumed by a 10 B.H.P. motor in one hour, with current at 4d, will cost 2-10.32 or 3.43 d per B.H.P. hour.

Power From Seeonday Batteries.— In charging a set of accumulators at, say, ]OO volts a pressure of 125 volts has to be maintained on the charging generator, which clearly illustrates a 20 per cent. loss. Therefore it is readily observed that it is not economical to run motors off accumulators, and this means that unless the demands for motor current is sufficient to warrant a generator running all day, motor current cannot be sold at a profit for a less rate than lighting current, the rapid discharge of current from cells such as required by motor is detrimental to the life of the plates.

Heating and Cooking. -Power is heat converted, therefore it naturally follows that power problems are on an even basis with heat, the difference only being that in power the heat is dissipated in energy and in cooking by radiation, consequently the comparative ensts set down in the power clause are applicable to heating. All systems are suitable for heating and cooking', the two gasses have a decided advantage in lowness of cost over electricity whereas electricity has the favour for convenience and cleanliness. Gas cookers and heaters cost less than 50 per cent, of electrical appliances.

We consider that to residents of an inland borough, where the heat of a summer must necessarily be trying to the housewife, the advent of a means of heating water and cooking would come as a real boon, and to secure the facilities upon a comparative coat with coal or wood fires must receive serious attention at the outset, especially when the cost of g i: is cooking on thy average is less than by coal fires. The factor governing the comfort of obviating the coal fires in the summer is that no heat is being added to the kitchen excepting at such times as cooking is in actual operation, and again for offices which are not provided with a fireplace heaters be installed at a low cost without alterations to premises and occupy very little floor space. Tne consumptoin for these purposes will naturally be heavier than for lighting, therefore it would be advis- ' able to install independent meters and charge the same rates as lor power purposes. —JAS. J. NIVEN & CO., LTD.