The approximate heating value of coal is 3.25 x 104 kj/kg (14,000 btulb). a modern coal-fired power plant rated at 1000 mw(el) requires a thermal input of about 2600 mw from fuel. (a) assuming operation at rated power percent of the time in a calendar year, how many kilograms of coal would be required? (b) if 6.2 percent of the coal used is discharged as ash, what is the annual ash accumulation?