Washington Montly: This winter, as Congress was scrambling to pass the stimulus package, the bottom fell out of the renewable energy sector — the very industry that lawmakers have held out as our best hope of salvaging the economy. Trade groups like the American Wind Energy Association, which as recently as December was forecasting “another record-shattering year of growth,” began predicting that new installations would plunge by 30 to 50 percent. Solar panel manufacturers that had been blazing a trail of …