1. The problem statement, all variables and given/known data 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? 2. Relevant equations 3. 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.