Mance: Quarry Industry of Southern Indiana 103 



One boiler ^^dth hand-fired, grate, and smok:e stack, all erected and 



bricked up $3,200 



Piping, heat, pumps, pipe covering, etc 2,000 



Total estimated cost $12,375 



In a general way the plant as above with one boiler Avould cost at the 

 present time $80 per kilowatt actual energy at 80 per cent power factor at 

 fuU load. 



If they want a spare boiler the same will have to be added, $3,200. 



Our estimate of cost of operation as follows, based on 10 hours per day, 

 300 days per year, average load of 150 kilowatts, being 450,000 kilowatt 

 hours per year at 50 pounds of feed water per kilowatt hour, being 22,500,000 

 pounds of water evaporated per year. Assuming the coal to be of pretty 



good quahty (13,000 B.T.U.) they ought to evaporate 7 pounds of water 

 per pound of coal, which would mean an annual coal consumption of 1 , 607 

 tons. 



1,607 tons of coal at $2 per ton $3,214 



One engineer, who will do his own firing, $75 per month 900 



Part of one man's time to wheel coal and ashes 150 



We assume that water wiU not cost anything 



All waste, and engine room supplies 300 



Repairs 75 



Overhead expenses, being 8 per cent depreciation, 5 per cent interest, 



1 per cent insurance, 1 per cent taxes, total 15 per cent of $12,000 . . 1 , 800 



Total annual operating expenses $6 , 439 



The above gives a cost per kilowatt hour of 1.43 cents. 



If the annual load is reduced to 115 kilowatts, 10 hours per day, 300 days 

 per year, the above estimate would change onlj- on the coal cost and result 

 in a cost per kilowatt of 1.65 cents. 



Cost of labor, etc., is estimated on Kentucky conditions. If a brick 

 stack is required instead of one of sheet steel, additional cost for the one-boiler 

 plant would be approximately $1,000, and for two boiler plants it would 

 be about $1,700 over the cost of the steel guyed stack, and a concrete stack 

 would probably figure out a little less than brick. 



The above estimate is based on using the Ball non-releasing gear Corliss 

 engine. 



The following figures as to cost of investment, coal consump- 

 tion, and other costs were submitted by one of the small operators 

 of the stone district for a calculation of the cost of power. The 

 cost is very low on account of the low first cost of the plant, due 

 to the fact that much first-class machinery was purchased second 

 hand in perfect condition at a very low price and that the repair 

 bills had been exceptionally low since the plant began operation. 

 The plant is kept in good condition and has been in operation 

 for three A^ears. 



