PRACTICAL OPERATION OF DYNAMOS. 



229 



TABLE SHOWING EFFECT OF LOAD FACTOR ON COST OF POWER. 

 Cents per Kilowatt-hour . 



If the station were run at full-load day and night the year 

 round the running expenses would be approximately as follows : 

 (a) Wages of one chief engineer at $5 per day, two assistant engi- 

 neers at $2. 50 per day (one to have charge at night the other during 

 the day), one lineman at $2. 50 per day, one lineman at $1.50 per 

 day, three helpers in the engine room (one at night and two dur- 

 ing the day) at $1.50 per day, and six men in the boiler room 

 (three at night and three during the day) at $1.50 per day, making 

 a total of $10,000 per year; (b) Coal at 6.3 pounds per horse- 

 power-hour and at $4 per ton would amount to $110,400 per 

 year; and (c) Petty stores would amount to about $6,500 per 

 year. The total annual expense of $147,900 would be the cost 

 of 6,000,000 kilowatt-hours, which would be at the rate of 2.46 

 cents per kilowatt-hour. 



If the station were run night and day the year round at an 

 average load equal to 0.20 of its full-load capacity, the running 

 expenses would be approximately as follows : (a) Wages (two 

 engine room helpers and three firemen less than before) would 

 amount to $7,260 per year ; (b) Coal at 8 pounds per horse- 

 power-hour and at $4 per ton would amount to $29,440 per 

 year; and (c) Petty stores would be, say, $5,500 per year. The 

 total annual expense of $63,200 would be the cost of 1,200,000 

 kilowatt-hours, which would beat the rate of 5.26 cents per kilo- 

 watt-hour. 



It would certainly pay in this plant to use a more economical 



