A system that has been adopted much abroad is the installation of a rural central station capa ble of supplying a number of farms, local in dustries and country estates . with electric current. This may be supplied with power generated by steam, water, gasoline, oil or gas, the co-operative feature resulting in a great sav ing in the production of electric energy. An example of the service supplied by a single central station in supplying a farming com munity may be seen in that of Lottin, Germany. Here a water power of 300 horse power is utilized. However, during certain seasons of the year, when the water is low, a steam gen erating set of 180 horse power is put into, use to keep up the service. It is obvious that this supplemental power may be pressed into use at any time, should the demand for power ex ceed the capacity of the hydro-electric station.
The distributing system of the Lottin sta tion is 82 miles long. The electric energy is used on 61 farms, including rural industries, and five villages, a total of 24,700 acres. Alto gether, 102 consumers are served, these having some 150 motors with a total of 1,500 horse power, the lighting equipment comprising 4,850 incandescent and 20 arc lamps. In one year the consumption amounted to 440,000 kilowatt hours. There are 50 farms, with an acreage varying from 60 to 1,800 acres per farm, under cultivation by the plough, with a total of 275 horse power in motors, 1,200 incandescent lamps and 20 arc lamps. Of these farms, 12 contain from 300 to 600 acres each, using 12 motors with a capacity of 122 horse power.
In order to give in concrete form the amount of electric energy necessary on a farm, the fol lowing figures from a 100-acre farm are given. It is assumed that two-thirds of the products are of a stalk nature, and that the live stock consists of 3 horses, 10 cows, 15 swine, etc. The figures are an average, talcen from the actual experience of a number of farms. It is also assumed that electric energy for power pur poses is 5 cents per kiloWatt hour, which is a reasonable figure for current used for power purposes only, when purchased from a public service corporation.
The average amount of water consumed on a 100-acre fartn is as follows: for the house, for each person per day, 5 to 6 gallons; for cattle, from 12 to 15 gallons per head; for swine and sheep, 1 to 2% gallons. For pumping 1,000 gallons to a tank elevated 35 feet, the power necessary is about one-eighth kilowatt hour, so that the yearly average energy for 3 horses, 10 head of cattle and 15 swine is about $4.
For a threshing machine of the smaller size, capable in 10 hours of threshing, cleaning and sacking, ready for the market, 80 to 200 bushels, 3 to 5 electric horse power are required. For machines of from 160 to 240 bushels capacity, 5 to 7 horse power are necessary; and from 300 to 800 bushels, from 10 to 20 horse power are required. The energy required for the various products to be threshed and cleaned, per 100 bushels, is, for rye, 25; wheat, 22; oats, 19; and barley, 21 kilowatt hours, or on the average, 22 kilowatt hours, costing $1, which is at the rate of $0.011 per bushel. If hay-baling machines are attached to the thresher, from four to six additional horse power are required.
Fodder cutters, varying from one to two horse power, consume 1.8 lulowatt hours per 100 pounds of fodder, costing 1/16 cent a cut, and as 10 head of cattle consume per year 60,000 pounds of cut beets, etc., the total cost annually for the energy used to operate the fodder ma chines is 50 cents per head.
One of the by-products of cotton-seed or linseed-oil mills is sold as meal or as cake, and to break it up a special machine is necessary. Such a machine often has a capacity of from 2,000 to 3,000 pounds per hour. The average amount of food per head of cattle is from 2 to 3 pounds per day, which amounts, for 10 head, to about 9,000 pounds per year. The cost of electric energy for operating this machine is 25 cents per year for each animal.
As the cattle are fed from 2 to 3 pounds of crushed grain per day per head, and as there are 10 altogether in the 100-acre supposition, a motor-driven grain-crusher is required, capable of crushing some 9,000 pounds per year. This might be prepared at one operation by a large mill, but for the purpose at hand a motor vary ing from 3 to 5 horse power, according to the size of the mill employed, will do the work conveniently. To grind 100 pounds costs $0.03 for the energy consumed, or for the 9,000 pounds, $2.70 per year.
For running the cream separator, a small motor of about one-fourth horse power can operate 300 quarts of milk per hour, consuming three-tenths of a kilowatt hour, at an expense of $0.01%. As the average production for 10 cows is amout 30,000 quarts per year, the yearly cost of operating the separator is $1.50.