Spiegel: The last 10 years have seen massive amounts of taxpayer money invested in renewable energies in Germany. Growth in the industry has been rapid. But has the development been universally good? SPIEGEL ONLINE takes a look at those renewables with promise — and those which might flop. It was all very small when it began. A couple liters of biodiesel here, a small wind turbine there. Maybe a few solar panels with an output just enough to run a pocket calculator. But then April 1, …