how much coal is required to produce 1000 kilowatts of electricity?

Answer 1

"World coal consumption is about 5,800 million short tons annually, of which about 75% is used for electricity production. When coal is used for electricity generation, it is usually pulverized and then burned in a furnace with a boiler. The furnace heat converts boiler water to steam, which is then used to spin turbines which turn generators and create electricity, with about 35–40% thermodynamic efficiency for the entire process. Approximately 40% of the world electricity production uses coal, and the total known deposits recoverable by current technologies are sufficient for 300 years' use at current rates.

It is perhaps more useful to put this into another unit of energy, kilowatt-hours. This is the unit that electricity is most commonly sold in. In that case, the energy density of coal is 6.67 kW*hours/kg. The maximum Thermodynamic efficiency of coal power plants is about 30%. That is, of the 6.67 kW*hours of energy per kilogram of coal, only about 30% of that can successfully be turned into electricity - the rest is waste heat. So really, coal power plants only obtain ~2.3 kW*hours/kg of burned coal." If those numbers are correct (and my math is OK), you'd need about 435 kg of coal to create the equivalent of 1000 kW hours of electricity.