Transphorm Looks To Save Lost AC/DC Energy

It’s a fact of physics: There’s AC and there’s DC. And in the process of converting electricity from one form to the other – going from the AC power that comes out of the wall socket to the DC power that runs your laptop, for instance – significant energy is lost. Maybe as much as 10 percent. How to overcome this waste? Use gallium nitride instead of silicon in the power conversion modules. That’s the solution that Google Ventures, Kleiner Perkins Caufield & Byers and other investors are betting $38 million on, backing a startup called Transphorm.

Transphorm says it has optimized gallium nitride for power electronics and “has developed novel devices such as transistors, circuits, and complete modules that include all the components needed to replace conventional systems,” according to MIT’s Technology Review.

laptop adapter, Transphorm energy conversion

image via Amazon.com

“The impact is huge – on the grid, on the planet,” Tranphorm chief Umesh Mishra said at an event at Google headquarters, according to the San Francisco Chronicle. “Whenever you use electrical energy, you’re paying a hidden tax due to the inefficiencies of power conversion.”

The Transphorm technology would also work, of course, in the other direction: energy stored in battery packs in electric vehicles like the Nissan Leaf has to be converted to AC to run the motor, and solar power systems use inverters to turn DC power into AC for household use. Gallium nitride would help make those systems 90 percent more efficient – and lighter and less bulky – Transphorm says. Those brick-like laptop adapters might finally be a thing of the past.

As good as this all sounds, Grist’s Todd Woody notes that long design cycles could mean that even if everything Transphorm says is true, gallium nitride will arrive slowly in devices. And as with most new technologies, gallium nitride modules are likely to be expensive until volume ramps up.

Pete Danko is a writer and editor based in Portland, Oregon. His work has appeared in Breaking Energy, National Geographic's Energy Blog, The New York Times, San Francisco Chronicle and elsewhere.