Through much of 2012, the Energiewende, Germany's pioneering effort to construct an energy system around renewables while simultaneously phasing out nuclear power and cutting carbon emissions, was on a roll. Plunging prices and eye-popping production figures for wind and solar power seemed to fulfill all the visionary prognostications. Germany shrugged off the shuttering of nearly half its nuclear plants without a backward glance: not only did it not suffer the predicted power shortages, it boosted electricity exports. Renewable power pushed market prices down and threatened to drive gas- and coalburning power plants into bankruptcy. The press and the green blogosphere celebrated passed benchmark after shattered milepost, including the day in May when, according to Treehugger.com's headline, "Half of Germany Was Running on Solar Power."