Renewable energy is unpredictable, thus you need a backup source of energy for when there's no wind, sunlight or rain. It's yet unfeasible to store large amounts of energy unfortunately so that means using either natural gas or coal, because you need to be able to rapidly increase/reduce/regulate the energy output. It's coal at the moment for Germany and that means more pollution and dirty politicians that don't care about the environment, just about votes. Actually nuclear power plants can nowadays also regulate their output fast enough, but they got rid of those.