38 PRESIDENTIAL ADDRESS SECTION A. 



Utilised : in Worcestershire, luigland, there is a water turbine 

 installation developing 40 h.p. wifli a fall of only 2 feet, while 

 at Lake Tunav, Switzerland, there is a plant with an ettective 

 head of 3,018 feet, each cubic foot of water per second yielding 

 260 h.p. It militates against small water power schemes that the 

 water supply is generally intermittent, so that a storage reser- 

 voir may be necessary. 



As compared with water ])ower, heat engines liave the 

 advantages of greater elasticity of site, thus obviating long- 

 distance transmission, and although water power is available, 

 the heavv capital cost required mav render water power much 

 more costlv than steam power, in spite of extremely low running 

 and maintenance charges, and the position is, in manv instances, 

 complicated bv the cost of electrical transmission. T'ut there is 

 one instance in California where power is economically trans- 

 mi'tted a distance of 232 miles, the electrical pressure being 

 50,000 volts. The (juestion of the maximum economical distance 

 of transmis'-ion for water jxiwer schemes is. of course, one 

 which can onl\- be solved l)v the consideration of many factors. 



CaDital cost is the main deciding factor in water power 

 installations. The average first cost of all American water 

 power schemes is given at £40 per h.p. developed, and it was 

 stated in a paper read at the British .Vssociation meetino^ in 191 2 

 that with water power scheme^ costing un to £20 per h.p. no 

 steam plant could compete. Tn the admiral)le report on Electro- 

 chemical Industries, issued by the Development of Resources 

 Committee of the South African Institute of Electrical 

 Eup^ine^^r'i. the followino' comparison between steam and water 

 power is .oiven : — 



Cost ov Electricity. 



" Steam Pmccr Station. — With a modern steam generating 

 station, assuming a capacity of 5,000 K.W., and a .suitable site 

 with a j)lentiful supply of cooling water, the total capital cost 

 should not exceed £15 ])er K.W'. for plant, with a further £5 per 

 K.W. for buildings and land. With a load factor of 0.83 

 per cent., the capital charges at 10 per cent, amoutit to 0.067 

 per unit, luiel with coal at 11,000 B.T.U.. costing 7s. 6d. per 

 ton, would amount to nearly 0.15 pence j^er unit. Repairs, 

 maintenance and stores about 0.06 pence ; labour and manage- 

 ment, say, 0.07 pence, so that the 'total cost — with the good load 

 factor of ?>2, per cent. — should not exceed 0.35 pence per unit. 



" Water Poiver Station. — Where suitable water power is 

 available so 'that the capital cost is, say, £30 per K.W. of plant, 

 the cajiital charge is (on the same basis as above) o.i pence 

 j)er unit generated. I'or re])airs and maintenance allow 0.04 

 pence, and for labour and management 0.06 ])ence. so that in 

 this case the total cost should be under 0.2 jience ])er unit." 



On these figures ithe cost for a horse power year would 

 be £9.53 for steam ])Ower, and £5.45 for water ])ower. 



