744 



ECONOMICAL ASPECTS 



a speculative matter, and past experience, knowledge of the art 

 and careful judgment must be exercised in arriving at the prob- 

 able life of apparatus and property. See Table LXIV. 



The operating expenses, which include labor, repairs, main- 

 tenance and supplies, will vary with the amount of power manu- 

 factured, that is, the load factor. They are, however, by no means, 

 proportional to it and form a much smaller part of the total cost 

 than with steam stations, where the fuel expenses come in and 

 where both labor, repair and supply items are much higher. 

 Based on a 50 per cent load factor, the operating expenses may 

 range anywhere from 0.3c. per Kw.-hr. for a small station to 

 0.02c. or less for a large station. Some approximate representa- 

 tive values are given in the following : 



TABLE LXV 



OPERATING EXPENSES OF HYDRO-ELECTRIC STATIONS 



TABLE LXVI 



APPROXIMATE COST OF STEAM TURBINE STATIONS AND POWER 

 (Based on Coal at $3.00 per Ton) 



