More and more energy firms are firing a proportion of biomass and waste in existing coal plants. It is a popular method to increase the share of renewable energy production, and to reduce the waste problems at the same time. But how ‘green’ is burning waste in coal power plants really? To find out, the Finnish Ph.D. student Johanna Heikinnen analyzed the burning behavior of fifty waste fuels, like chicken litter, bone meal and paper sludge. Heikinnen found that co-firing biomass and waste doesn’t always mean a reduction of emissions, and could actually reduce the efficiency of energy production. Read more here