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Google Offers a Million Bucks For a Better Inverter

Posted by Soulskill on from the go-small-or-go-home dept.

An anonymous reader writes: With the Little Box Challenge, Google (and IEEE, and a few other sponsors like Cree and Rohm) is offering a $1 million prize to the team which can "design and build a kW-scale power inverter with the highest power density (at least 50 Watts per cubic inch)." Going from cooler-sized to tablet sized, they say, would make a whole lot of things better, and the prize is reserved for the best performing entrant. "Our testing philosophy is to not look inside the box. You provide us with a box that has 5 wires coming out of it: two DC inputs, two AC outputs and grounding connection and we only monitor what goes into and comes out of those wires, along with the temperature of the outside of your box, over the course of 100 hours of testing. The inverter will be operating in an islanded more—that is, not tied or synced to an external grid. The loads will be dynamically changing throughout the course of the testing, similar to what you may expect to see in a residential setting." The application must be filled out in English, but any serious applicants can sign up "regardless of approach suggested or team background." Registration runs through September.

2 of 260 comments (clear)

  1. I've heard this one... by roc97007 · · Score: 5, Interesting

    ...happened many years ago. The government speced a power supply so clean that it couldn't economically be done at the time. The company that won the contract produced a box that met all the specs. Except that it failed after several hours of use. Opening the box, they found the power cable connected to a strain relief and the main power provided by a lead-acid battery.

    Word is, there was no spec for lifecycle so the devices met the contract as stated, and the government couldn't return the devices.

    So I'd recommend to Google: At some point, look in the box.

    --
    Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
  2. Re:Why? by viperidaenz · · Score: 4, Interesting

    and this is the reason it is 48V.
    Copper is expensive. You don't want your 42U rack, which pulls 8kW powering it's 42 1U servers, drawing upwards of 700A.

    For a 1% power loss over 1 metre at 700A, you need 0000AWG cable. It's about 1kg of copper (that's a single conductor, you'd need one for the return path, another kg and another 1% power loss)
    But 0000AWG can't actually handle that amount of current without active cooling. for 90C rating, it's only 260A.

    700A for 1M distance has cost you 160W of power and 2kg of copper and you need some fancy cable cooling technology.

    If you upped the voltage to 48V, you only need 175A.
    You'll be fine with 2AWG cable if you can keep it cool and only lose 30W. You could use 0AWG, which would cost you 1kg of copper and only have 19W of wasted power.