P. S. C., 2d D.

public and must continue to serve the public. The problem concerning electric energy generated at Niagara Falls is very great. It involves elements which are now insoluble. The amount of energy available and to be available for the next ten years from this source is unknown. As has been indicated in the case, there is a grave possibility that steam power will have to be resorted to for the supply of electric current in the near future in the city of Buffalo. If such is the case, that fact may demand an entire revision of the rates herein fixed, not only in case a steam plant is erected, but also in case its erection is contemplated, for the reason that a very considerable further investigation may be needed to determine whether the rates fixed would be remunerative with a steam plant producing part of the energy consumed. The calculations in this case, elaborate as they have been, relate to hydro-electric energy as against steam generated energy, and no calculations have been made which warrant any conclusions as to the cost of energy partly derived from water generation and partly from steam generation.

All of the foregoing considerations have been kept in mind in the determination of this case. The subject under consideration has been so vast in extent; the factors to be considered are so complex, involved, and in many respects contradictory and uncertain, that the Commission can not feel sure that errors have not crept into its calculations and that its conclusions may not be to some extent erroneous in matters of detail.

Vol. III

APPENDIX

The diagrams on the following pages show graphically the average kilowatt-hour for various hours use of maximum demand, for each of the proposed rates.

rates per

A simple illustration will explain the use of these diagrams. Suppose a residence customer has installed a total capacity in lamps of 1000 watts (= 1 kilowatt). Then his maximum demand would, in accordance with the proposed residence lighting rate, be one-quarter of 1000 watts= 250 watts, or 14 kilowatt. Suppose, further, that the consumption of current for a given month as shown by the meter is 50 kilowatt-hours. Then the hours use of the maximum demand is 5014200.

(By hours use is meant the number of hours which would be required, when using current at a rate equal to the maximum demand, in order to consume an amount of energy equal to that which was actually consumed. The hours use is, therefore, equal to the consumption in kilowatt-hours divided by the maximum demand in kilowatts.)

The bill would be computed as follows:

Average rate=2.33÷50=4.66¢ per kilowatt-hour.

By inspection of Diagram No. 6, it will be seen that the rate corresponding to 200 hours use of maximum demand is 4.66 cents, just as calculated above. The function of these diagrams is merely to show at a glance the results which would otherwise have to be laboriously figured out.