Germany jump-starts the supergrid

New developments in high-voltage DC electronics could herald an epic shift in energy delivery. Stuttgart is one of the last places you´d expect to find in a power pinch. This south German city´s massive automotive plants run 24-7 without a hiccup, efficiency measures have held industrial power consumption flat, and solar panels flash from atop its major buildings. But now all that is at risk. The country´s accelerated shift from nuclear power and fossil fuels to renewable resources, such as wind and solar, has exposed a huge gap in its transmission capacity. If they are to survive, Stuttgart´s factories-and power consumers across southern Germany-will need to import a lot more power from the north, and Germany´s grid is already at capacity. To fill the gap, Germany is considering an aggressive plan that would push high-voltage direct current, or HVDC, from its conventional position on the periphery of AC grids to a central role. The primary reason is simple: For the first time, HVDC seems cheaper than patching up the AC grid. But Germany´s transmission planners also have another motivation: They want to provide as much performance and reliability as they can to an AC grid that´s already strained by excess wind power. For that, they´re considering implementing power electronics that are capable of doing something that´s never before been done on a commercial line: stop DC current in milliseconds flat.