Google Challenge Results In Astoundingly Efficient Inverters

AmiMoJo writes: A few summers ago, Google and IEEE announced a one million dollar prize to build the most efficient and compact DC to AC inverter. It was called the Little Box Challenge, with the goal of a 2kW inverter with a power density greater than 50 Watts per cubic inch. Typical solar inverters have a density of about 5 W/cubic inch. Now the results are in, with the winners hitting 143 W/cubic inch using GaN transistors, and two other teams meeting Google's goal.

Comments

AC is by its very nature inefficient

[Anonymous Coward]

We should not be generating AC power in the first place. DC is much more efficient.

Re:AC is by its very nature inefficient

[IcyHando'Death]

You know the same thing could have been (and was) said about the switch from an analog phone system to digital. Every phone, every piece of switching equipment, every repairman's kit had to change -- all at enormous expense. It paid for itself though, by increasing profits (companies could charge for the new services that were made possible). All it would take is for some upstart startup to begin hooking up DC power in some new neighborhoods to get the game going. I don't even know if that would be legal now in most places though. The entrenched power monopolies would be a big obstacle to overcome.

Re:Efficiency

[DeathToBill]

Maybe, though Hack-a-Day say it involves an "incredible thermal management solution," which doesn't sound like they've actually bumped the energy efficiency up that much.

Why were Google so keen to have an inverter that maximises power density? Why not maximise energy efficiency?

Ideally you'd like to minimise cost of energy. But I guess it's fairly difficult to construct a competition around this: It depends too much on production scale and the prevailing cost of electricity. But why power density as a substitute?

Split phase

[shawn2772]

Another nice improvement the winners made above the requirements was that Google asked for 230 or 240 VAC output, but the winning device provides 240 VAC split phase, which means it can also be used to provide two legs of 120 VAC. Not that it's terribly hard to add a 240 VAC -> 120 VAC transformer, but with this design there's no need.

Re:Watts per cubic inch?

[Anonymous Coward]

Seriously? An Anonymous Coward (guess I can't use AC in this discussion) got a +3 insightful for simply bitching about the US being non-metric? That's a pretty low bar the mods have set there.

Re:Efficiency

[AmiMoJo]

Batteries. Current inverters are rather large compared the batteries that can provide their maximum output power.

Electric vehicle charging would benefit from this. You want to be pushing 120kW+ DC into the battery. You can also go back the other way and run your house from the car battery to save money when your solar panels are not producing anything.

Re:GaN Transistors are the future

[Anonymous Coward]

I work in RF, Ku band stuff, we use GaN parts like candy. One day I noticed that these things always come straight from Japan in hand-written and hand-packed little boxes... I asked what the BOM cost was and it was very high!

These things are so cutting-edge that you can't even google for the part number they ship you; it's not even on the manufacturer's page! You need to ask for the datasheet and often it's just screen printouts from the VNA...

I've also noticed that they smell different when the top explodes because of a mismatched load.

Re:Who participated?

[silas_moeckel]

Because registering a team is somehow hard for minorities or women? The fact they had to use the internet or english? Please describe a change faced by these groups that a white male from Appalachia would not also face?