I have written before about the Energiewende, or “energy transformation,” underway in Germany. In 2011, the German government made the monumental decision to phase out of nuclear power entirely by the end of 2022, and cover the electricity shortfall through energy efficiency and renewable power. Observers have debated ever since whether this decision was genius or folly. One thing that is indisputable, however, is that in response to this commitment, German engineers are innovating. The country is becoming, by necessity, a leader in managing renewable energy on a grand scale. This is a major challenge. As more and more intermittent wind and solar power is added to the national mix, Germany must develop new ways to manage its power grid to assure stability and meet demand—day and night, rain or shine.