The cost to produce power from water is often compared with the cost to produce from coal on the basis of continuous operation for twenty-four hours a day. For street railway service this method gives a false impression, since it implies that the machinery is working at its full capacity for 8760 hours per annum, or 100 per cent load factor; as a matter of fact, for street railway service a load factor of 33 per cent is high.

To look at this from another point of view, the demand for power for street railways cannot be increased at will, as it may be in a manufacturing concern. In the latter, if it is found advisable to run night and day at full capacity, instead of ten hours, there is produced a correspondingly greater amount of the product, be it flour, steel rails or carbide of calcium, and this output is produced at a correspondingly decreased cost per unit.

For street railway service, on the other hand, there has to be installed sufficient generating machinery to take the peak of the load.

This is usually three times the average and is only of a few hours duration each day. If it were necessary or profitable to use this full capacity continuously for other industries, it would be possible to do this with very little increase of labor, no increase of fixed charges and the additional expense of producing the greater output would be merely the coal and a slight increase of supplies and repairs. This combination is the feature of the Niagara Falls work.

When the expense of transmission shall have been decreased by the successful employment of higher voltage, it will then become a problem as to whether it will not be profitable to produce power from a steam plant located at a coal mine, coal costing in this case but eighty cents a ton. This would bring the cost of fuel down to .12 of a cent per K. W. hour, as against .33 of a cent for standard plant. Further, this expense would only continue for the comparatively small number of hours that the plant would have to be operated for street railway service. This might be better economy than to pay the fixed charges that would accrue from the expensive development of water powers at possibly much greater distances.

It is to be noticed in this connection that the cost of installing the steam station would be considerably less when located at the coal mine, since it would then be unnecessary to equip with the most economical and expensive machines.

Water power produced in various parts of the country varies greatly in its cost. It is reported that the electrical energy so produced costs from fourteen dollars to thirty-two dollars per annum per K. W. continuous output. This expense is largely made up of fixed charges, which increase rapidly as the expense of making the necessary improvements is greater. The standard steam plant produces power with three dollar coal for twenty-nine dollars and with

3

DURATION.

TABLE NO. 2-CONTINUED.

S 10 11 12 13 14 15 16 17 18 19 23 25 26 28 29 30 31 32 33 34 35 37 40 42 43 44 45 47 48

2 2 2 2 2

3

2

2

2

2

2

2

2

2

2 2 2 2 2 2 2 3 3 2 3 2 2 2

8

12 12 12 12 12

8 12 12 12

12 12 12

12

10 10 10 12 12 12 12 12 8 8 12 8 10 12 10

SHIFT, HOURS.

8760 8760 8760 8760 4380 8760 8760 8760 744 4380 8760 8760 744 7300 7300 7300 8760 8760 4392 8760 3624 8760 8760 8760 8760 600 4380 7300

MEN PER 1000 K. W. 1.94 7.5 3.7 3.7 3.0 1.87 6.3 3.7 3.7 3.7 3.0 3.3

5.0 3.2 3.0 4.5 3.5 5.0 5.0 2.1 8.0 2.7 5.0 3.7 3 3 3.0 8.0 67

2.10 3.30 1.43 .75 .60 3.44 1.05 1.15 1.63 2.80 3 2.84

3 3.08

3 3.08 1.0 1.241.75 1.60 1.60 2.70 1.60 1.902.122.75

19.252.66 27.296 1.03 .29 .39 .57 .55 .49 .62 .52 .66 .27 .29 .63 .24 .45 .50

.68 1.7 .56 1.21.02 1.03 .91 1.1 .84 1.5 .57 .48 1.85 .52 .921.03

69 .66 1.16 1.02

FIXED CHARGES.

.405

.44 .24

24