Breakthrough could carry solar, wind power long distances

By Laura Shin | December 12, 2012

We know we have a problem with carbon emissions mucking up the climate.

But switching over to renewable energy isn’t that easy. For one, many places that are good for making renewable energy — windy plains or sunny deserts — aren’t necessarily near big cities, where the energy is needed.

And what happens when you try to transport energy hundreds of miles from the energy source to the big city? It loses some of its power. At least today’s dominant form of power, alternating current (AC), does.

But Thomas Edison championed direct current (DC), and it looks like he might be vindicated.

Up till now, DC was not used on large power grids because of the energy it loses when carried over long distances and for fear it would be prone to catastrophic breakdowns. (More on that below.)

But a new type of power, high-voltage DC, or HVDC, could carry power long distances with minimal loss — and a new device called a hybrid HVDC breaker would help prevent those huge breakdowns.

Developed by Swiss power technology company ABB, the breaker has only been tested in the lab, but ABB claims the hybrid HVDC breaker will make possible “the grid of the future,” which National Geographic News describes as “a massive, super-efficient network for distributing electricity that would interconnect not just nations but multiple continents.”

What the hybrid HVDC breaker is and why it’s important

The thing about HVDC, or any direct current for that matter, is that, unlike AC, it’s always on.

That makes it much trickier to regulate.

“When you have a large grid and you have a lightning strike at one location, you need to be able to disconnect that section quickly and isolate the problem, or else bad things can happen to the rest of the grid,” such as a catastrophic blackout, ABB chief technology officer Prith Banerjee told Nat Geo News. “But if you can disconnect quickly, the rest of the grid can go on working while you fix the problem.”