Fig. 128
Fig. 129
We might take as the type of hydro-electric central station, that is, one which generates electricity by water-power, the Glenwood Station of the Central Colorado Power Company. This station has two 9000 horse-power water turbines. Each water-wheel drives an alternating-current generator which develops 4000 volts of e. m. f. These water wheels and generators are shown in [Fig. 129]. The penstocks are to be seen coming through the back wall of the building. They bring water at 170 foot head, or about seventy-five pounds per square inch static (standing) pressure. Three huge transformers, each weighing twenty-six tons, step up the e. m. f. from 4000 to 100,000 volts. These are the cylinders shown in [Fig. 130]. They simply contain a great many coils of copper wire with a vast amount of iron at the centre. They accomplish in a large way what our spark coil does in a lesser degree. But why go to all this expense to produce such a dangerous and troublesome voltage? The answer briefly is, that while it is dangerous and troublesome the expense is not so great as it would be to supply by any other method the electric current required. Denver and numerous other places, large and small, require electric current. From one to two hundred miles away on the Grande River, there is vast power running to waste. We have to choose on the one hand between buying power in the shape of coal and distributing power plants to those various localities where electricity is needed, and on the other using this water-power, which is now running to waste, to generate electricity which we may transmit and distribute throughout the one hundred and eighty-five miles to Denver, Leadville, Boulder, Dillon, Idaho Springs, etc. But electric energy transmitted a long distance suffers great loss.
