The first hydro-electric central station in the United States was installed at Appleton, Wis., it 1882. The use of hydro-electric power for lighting advanced rapidly during the 80's, this advance following quickly the invention of the incandescent lamp by Edison in 1879. While there were some previous experiments carried out, the first large scale successful long distance power transmission was that from Lauffen to Frankfort, completed in 1891, by which 110 horse power was transmitted a distance of 112 miles at 12,000 volts. This provided the initial stimulus for extensive hydro-electric ‘elopment. Prior to that date, water power was not much used for the generation of electric current unless the water power happened to be located very near the site where the current was to be used.
The growth of hydro-electric power devel opment has taken place mainly along natural economic lines. In general water powers near large industrial centres were developed first, and of these, those involving the lowest primary investment have been given preference; further more, the first water power developed in a local ity has generally been that having a size suited to the demands of the immediate future. Thus it happens that some of the very largest water powers, as well as numerous smaller ones, have thus far remained undeveloped. The necessity of developing powers of a size suited to the existing market conditions at the time of de velopment is emphasized by the fact that many of the larger hydro-electric developments in the eastern United States passed through bank ruptcy, but are now operating successfully. The cause of the financial difficulties was in general that it took too much time to build up an adequate market for the output of a power larger than the immediate demand. and during this time the revenue was insufficient to meet Interest payments and other fixed charges on the large investment.
There has been • progressive advance both in the modes and extent of utilization of elec tric power, especially hydro-electric power. Originally, its principal uses were for street lighting and street railway traction. In east ern United States good roads and automobiles have lessened the latter demand, although in the Pacific Coast States electric railroads afford the principal means of transport between im portant commercial centres,— coal is more costly — and a large proportion of the hydro electric power produced is used for traction purposes. In the meantime electric lighting has greatly increased in efficiency. The amount of current required per candle power is much less than formerly. This has stimulated the
use of electricity for lighting purposes, and the demand for electric current for ornamental pub lic lighting, and for domestic and commercial lighting and advertising. is rapidly increasing, especially where current produced by water power can be supplied cheaply.
The introduction of hydro-electric power for manufacturing purposes took place more slowly than its use for lighting and traction. At the start almost every manufactory had its own steam or water-power plant, with a complicated system of shafting and belting to drive indi vidual machines. To replace this system by the use of motor drives for individual ma chines, equipment representing a large invest ment must be discarded. The development of highly efficient variable speed motors, with large initial capacity for starting, combined with the many advantages of direct electric drives for each machine, and the increasing cost of coal and labor, have brought about within the past decade a gradual introduction of the use of hydro-electric current for power in manufacturing. This gives promise of rapid ex tension in the immediate future. Not infre quently manufacturing plants owning water powers have installed electric generators, and have also connected their plants with the trans mission lines of commercial electric companies. If, as usually happens on variable stream', the water power alone is insufficient to supply all the power required by the manufactory during low water periods, the current is then purchased from the distributing company to make good the deficiency, instead of generating auxiliary power by steam.
When the stream supplies more current than is required, or at night or other times when the manufacturing plant is shut down, the water power which would otherwise go to waste is converted into electric current, and this is turned on to the commercial distributing lines, thus effecting an interchange of power advan tageous to both parties. The use of inter-con nectittg distribution lines, or of a common dis• tribution system, supplied by several hydro electric power plants owned by different com panies or individuals, with an agreement for interchange of surplus power, is now being ac complished in several instances. This procedure bids fair to stimulate the electrical development or re-development of numerous smaller water powers going to waste through non-use or aban donment, or which are now inefficiently used mechanically for manufacturing purposes.