Gas or Coal?
By: Samuel Goin
 Boiler replacement
The 20 Year
Plan
 The life is said to be 20 years long.
 The system will be expected to produce 145,000,000
lbs of steam per year.
 1 lb of steam = 1000 BTU
 Must have an electrostatic precipitator to clean exhaust.
 Initial Cost:
 System: $2,570,300
 Precipitator: $145,000
Coal Option
 Fuel Cost: $125 per metric ton of coal
 1 lb of coal = 14,300 BTU
 Efficiency: 75%
 Must use Gas with an Oil switch-on.
 94% gas and 6% oil
 Initial Cost: $1,298,340
 Fuel Cost:
 Gas: $14.50 / MCF (Million Cubic Feet)
Gas Option
 Oil: $2.93 / gallon of oil
 1 lb gas = 1000 BTU
 139,400 BTU / gallon of oil*
 Efficiency:
 Gas: 78%
 Oil: 81%
*When using 139,400 BTU / MCF of oil as stated in the problem, cost of oil per year became $1.69 trillion a year.
Did research and found a real-life answer of 138,690 BTU / gallon or oil (1).
 Taking the 75% efficiency into account, the yearly cost
for fuel to operate the coal plant will be $766,566.70.
Coal Option
Cost
 This means the cost per lb of steam for the coal plant is
$.0053.
 The annual equivalent cost is $1,080,920.13 over 20
years.
 The cost of the gas to operate this plant is $2533.78 a
Gas Option Cost
year when considering the 78% efficiency and the cost
of oil to operate the plant is $225,755.78 when
considering the 81% efficiency. This means the total
yearly operational cost for fuel will be $228,289.56.
 This means the cost per lb of steam of this system will
be $.0016.
 The annual equivalent cost of this system is $378,136.41
over 20 years.
 AEC(coal) = $1,080,920.13
 AEC(gas) = $378,136.41
 AEC(gas) << AEC(coal)
Decision
 As there are no other thing to consider other than the
annual cost, the gas option is far superior. Unless an
unforeseen additional cost or early replacement is
needed the gas system is much more cost effective.
Citations
1.
“How to compare Oilheat,” Haab_Energy_2018.png. [Online]. Available:
https://www.fchaab.com/fuels/how-compareoilheat/#:~:text=A%20BTU%20is%20the%20amount,has%20138%2C690%20BTUs%20per%2
0gallon. [Accessed: 21-Nov-2021].