High-voltage DC transmission lines carry electricity from China’s massive Three Gorges dam, the largest power plant in the world. Advocates of HVDC think it has an even greater role to play in bringing renewable energy to the grid. Photograph by Zheng Jiayu, Xinhua Press/Corbis

High-Voltage DC Breakthrough Could Boost Renewable Energy

Patrick J. Kiger
For National Geographic News
Published December 5, 2012

Thomas Edison championed direct current, or DC, as a better mode for delivering electricity than alternating current, or AC. But the inventor of the light bulb lost the War of the Currents. Despite Edison’s sometimes flamboyant efforts—at one point he electrocuted a Coney Island zoo elephant in an attempt to show the technology’s hazards—AC is the primary way that electricity flows from power plants to homes and businesses everywhere.

But now, more than a century after Edison’s misguided stunt, DC may be getting a measure of vindication.

An updated, high-voltage version of DC, called HVDC, is being touted as the transmission method of the future because of its ability to transmit current over very long distances with fewer losses than AC. And that trend may be accelerated by a new device called a hybrid HVDC breaker, which may make it possible to use DC on large power grids without the fear of catastrophic breakdown that stymied the technology in the past.

Swiss-based power technology and automation giant ABB, which developed the breaker, says it may also prove critical to the 21st century’s transition from fossil fuels to renewable energy sources, by tapping the full potential of massive wind farms and solar generating stations to provide electricity to distant cities.

So far, the device has been tested only in laboratories, but ABB’s chief executive, Joe Hogan, touts the hybrid HVDC breaker as “a new chapter in the history of electrical engineering,” and predicts that it will make possible the development of “the grid of the future”—that is, a massive, super-efficient network for distributing electricity that would interconnect not just nations but multiple continents. Outside experts aren’t quite as grandiose, but they still see the breaker as an important breakthrough.

Read more: High-Voltage DC Breakthrough Could Boost Renewable Energy — National Geographic.

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