Waste power plant efficiency math problem

[courtneywetts]

Homework Statement

If 230 million tonnes of solid waste were burned in waste-to-energy power plants that are 20% efficient

a) how many kilowatt- hours of electrical energy could be produced in a year? Compare this quantity with the total US electrical energy production of 3.8 trillion kWh annually

b) what would be the equivalent average electric power output from all those waste- burning power plants? How many 1- GW coal- fired plants could they displace?

Homework Equations

The Attempt at a Solution

For part A, I am not sure how to calculate kWh. I know that 1 tonne is equivalent to 1000 kg. I am not sure if this is relevant in any way.

 

[courtneywetts]

Also the energy density is 20 MJ/kg not sure what this means though