AmiMoJo writes: In the US, electricity demand is growing very slowly, which means that capacity additions don't have to exceed retirements by much in order to keep the grid functioning. Tracking the comings and goings from the electric grid can help provide a picture of the country's changing energy mix. The Energy Information Administration, which provides data on the US' electric grid, says 18GW of capacity were retired this past year, more than 80 percent of it coal-fired. More than 27GW of utility-scale projects will replace that this year. Note that much of the new generating hardware is wind and solar, but the plants being replaced often had low capacity factors due to their age and high pollutant output.