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Power Google Technology

Google Offers a Million Bucks For a Better Inverter 260

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.
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Google Offers a Million Bucks For a Better Inverter

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  • An awesome way to smuggle a wifi sniffer - or something naughtier - into the googleplex!

  • by roc97007 ( 608802 ) on Tuesday July 22, 2014 @05:53PM (#47510893) Journal

    ...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.

    • That would be a rectifier. Google wants an inverter.
    • by geekoid ( 135745 ) <> on Tuesday July 22, 2014 @06:01PM (#47510947) Homepage Journal

      Based on a weak urban myth?
      Besides, if you get a battery that can do this work and meet these conditions, you would have invented a new type of battery. One that would make you billions.

    • Re: (Score:2, Insightful)

      by Anonymous Coward

      At 50 W per cubic inch, you'd make more money by just selling those batteries if they last longer than a few hours...

    • by Anonymous Coward

      Now you know why government contracts have to be so complicated.

      To fight dickery.

    • by viperidaenz ( 2515578 ) on Tuesday July 22, 2014 @06:49PM (#47511355)

      It needs to last for 100 hours of testing.
      It must be smaller than 50W/in3

      That's 305000W.h per litre. 1100MJ/Litre.

      If you've got a battery with that kind of power density, $1M is chump change. You've solved the electric car problem, since you've got well over 1000x the power density of current lithium batteries.

      • by Anonymous Coward on Tuesday July 22, 2014 @07:46PM (#47511717)

        since you've got well over 1000x the power density of current lithium batteries.

        Energy density. And nearly 100x that of gasoline, too.

      • by Beck_Neard ( 3612467 ) on Tuesday July 22, 2014 @08:22PM (#47511991)

        If you've got a battery with that kind of power density, it's actually a formidable explosion hazard. With thirty times the energy density of rocket fuel, even a minor internal short would cause a chain reaction that would make a battery pack the size of a laptop battery explode with the power of over one hundred kilograms of TNT.

        • Given that this would be upwards of 2000x higher density than a lithium battery, does that mean a 60Wh laptop battery has the explosive capacity of half a stick of TNT?

          60Wh = 216kJ
          0.19kg stick of TNT = 532kJ

          The 65L of petrol in my car stores 2340MJ and is equivalent to nearly a ton of TNT.

          TL;DR: Comparing batteries to explosives is a bad idea. They're completely different. A battery isn't going to explode, it's going to burn.

          The difference between burning petrol and exploding petrol is your car running perf

      • by rtb61 ( 674572 )

        There appears to be a significant flaw in the specification. Technically whilst the inverter is limited in size, they have not limited what the inverter is contained in, so a liquid nitrogen bath comes to mind. Doing so makes the inverter quite easy to achieve and the temperature would remain very low even excluding the affect of the liquid nitrogen beyond it's super conductivity enhancing ability. So they should require the inverter function in a room temperature environment.

        This is really all about mat

      • by PPH ( 736903 )

        That's 305000W.h per litre.

        This isn't an energy storage device. It' an energy conversion device and as such stores nothing*. Think of it as a piece of wire. Power in, power out. With some minor loss which produce heat. An inverter is just 'magic wire' where DC goes in and AC comes out.

        *Technically not exactly true, as an inverter has some smoothing filters. But they store energy for a time period on the order of half an AC cycle, not hours.

    • by afidel ( 530433 )

      If you can provide 2kva for 100 hours from 40in^3 you'll have a lot now than $1m coming your way! Heck the Nobel committee alone will give you $2m, $1m each in physics and chemistry.

  • Why? (Score:4, Interesting)

    by Obfuscant ( 592200 ) on Tuesday July 22, 2014 @05:58PM (#47510931)
    One question: why?

    If you're running devices that need a kW you're already at a reasonable size for your device, and you can build a lot of cheap, larger inverters for what it would cost to build this small one.

    You could also probably build the powered devices to run off 12V for less than what this inverter would cost.

    Is what is keeping AC power from the hinterlands this is intended to serve really the size of the inverter, or is it more likely the cost?

    • by sribe ( 304414 )

      You could also probably build the powered devices to run off 12V for less than what this inverter would cost.

      Lower voltage, higher amperage required for same power, rapidly increasing power loss with increasing wire length, even at residential scale. There's a reason that your power supply for your 12V lights goes close to the lights and you don't run 12V through your house.

      • It could work if you're only going from bottom of rack UPS to rack equipment. It's already done in some datacenters, though usually at 24 or 48V rather than 12V.

        • by sribe ( 304414 )

          It could work if you're only going from bottom of rack UPS to rack equipment. It's already done in some datacenters, though usually at 24 or 48V rather than 12V.

          Oh, absolutely yes in data centers. But not in houses.

        • Re:Why? (Score:5, Interesting)

          by viperidaenz ( 2515578 ) on Tuesday July 22, 2014 @07:10PM (#47511469)

          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.

          • 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)

            Bah, just use the chassis as return; the frames might only be steel, but there's a good amount of it. That and I suggest 600V for truly limiting the amount of power lost through cables. ;)

    • by Hadlock ( 143607 )

      The wiki page they link to has a photo of a converter that converts solar DC to electric grid AC. I'm not sure if they're looking to do residential solar with the inverter on the back side of the panel group or use this in a datacenter...

    • Re: (Score:3, Informative)

      by Anonymous Coward

      > One question: why?

      Why does Google care about inverters?

      We believe that inverters will become increasingly important to our economy and environment as solar PV, batteries, and similar power sources continue their rapid growth. More broadly, similar forms of power electronics are everywhere: in laptops, phones, motors drives, electric vehicles, wind turbines, to give just a few examples. We expect that the innovations inspired by this prize will have wide applicability across these areas, increasing ef

    • by serbanp ( 139486 )

      Having read the actual Spec Document, the input voltage is 450V DC, with an equivalent series resistance of 10Ohm. Definitely not 12V DC.

  • so... (Score:4, Insightful)

    by serbanp ( 139486 ) on Tuesday July 22, 2014 @06:07PM (#47510993)

    what is the state of the art w.r.t. the 12VDC->110VAC/60Hz 1kW inverters?

  • An inverter converts DC power to AC power. The most obvious use is for solar power. For rooftop solar arrays, you want efficiency, but you don't care much about density. In many cases, you have a small inverter under each panel, and size isn't an issue. But if you could get a few percent more AC out for a given DC in, that would matter.

    On the other hand, if you want a solar-powered Chromebook, the inverter could be a deal-breaker on the weight. I'm guessing it's applications like that that have inspire

    • Low-power inverters used to be common in laptops to drive the backlight. You still see them sometimes, but most new laptops use LED backlights now. No need for inverters on those. That's a good part of the appeal.

    • A chromebook would run off of DC power, so the inclusion of an inverter would be a waste of technology. Why take the DC from solar cells and invert it to line-voltage AC just to rectify it again to the 12Volts and lower that a chromebook would use?
      • by crow ( 16139 )

        Yup, you're completely right. I'm not sure what I was thinking. Probably too much air conditioning froze my brain.

    • "if you want a solar-powered Chromebook"

      I'm a little confused... why would you convert dc to ac, only to convert it back to dc for the computer to use? If it's a dedicated power source for one device, wouldn't it make more sense to keep it dc?

    • But I don't get it - why convert DC to AC, when all you're likely to do in the end is convert that AC back to DC somewhere else to actually power something?

      • Because AC is a consumer standard? There are no consumer standard for DC power, other than AA, AAA, C, D, and 9V.

        ... Okay, and car cigarette lighters and microUSB.
    • by Khyber ( 864651 )

      "On the other hand, if you want a solar-powered Chromebook, the inverter could be a deal-breaker on the weight."

      You wouldn't need an inverter, really. In many cases, low-power laptops run on ~10VDC, so a direct solar panel connection with resistor would be roughly fine to hit the battery through its charge controller. For those needing ~20V, you just use a cheap-ass boost converter and resistor before you feed to the charging/power circuitry.

      Been there, done that, made solar-powered headless laptop servers.

  • by hchaos ( 683337 )
    If you can pull this off, I'd guess it would be worth a lot more than $1M.
    • Developing a working prototype and developing a commercially-feasible product are two different things. You could conceivably meet the requirements of this, but by using components or techniques that are not commercially feasible due to cost, safety, or other issues. However, it would be a big step in the direction towards doing such a thing. Google is paying for you to help make that step... not necessarily to develop a device that's worth commercializing.

      • Here is a silly question of sorts.

        what is in the process of making this, you used some patented off the shelf part and perhaps created something else as a part inside it that seems to be covered by a patent.

        I'm assuming that as long as you don't sell it, the off the shelf part is covered (maybe even if you did sell it) but the other patent, would it require royalties or whatever just for this proof of concept device because it won a prize? Of course I could be wrong on it all, I don't really know the answer

  • by drinkypoo ( 153816 ) <> on Tuesday July 22, 2014 @06:37PM (#47511257) Homepage Journal

    Stupid objection the first: "This is worth a lot more than a million dollars."

    Does Google own the intellectual property created during the competition?

    No. Google is not requiring any IP or licenses be granted except a non-exclusive license to be used only for the purpose of testing the inverter and publicizing the prize. [...] However, in the spirit of advancing this power electronics community, Google may choose to make public some or all of the teamsâ(TM) high-level technical approach documents

    Stupid objection the second: (something stupid about 12 volts)

    Will be taking in 450 V DC power in series with a 10 Ω resistor
    Must output 240 V, 60 Hz AC single phase power

    I know that slashdotters don't RTFA, but seriously, all of you jaw-jacking about 12 volts or about how a million is chump change are a bunch of Useless McToolbags. STFU already.

    • by MacDork ( 560499 )
      Go ahead and do lots of work with almost no chance of payment. If you don't win, you don't get anything, no matter how much time you put into it. That works out really nicely for Google. That doesn't work out so well for every contestant except for the one who wins.
      • Go ahead and do lots of work with almost no chance of payment.

        If you aren't already working on this, or don't already have a pretty good idea with at least a fair chance of succeeding, then you're probably not too smart if you decide to take this challenge on. So what? There are those who are working on solving this problem already. If they have the means to produce a product, they're already doing that. If not, then this will give them some money for production of prototypes for larger systems, and probably attract some investment dollars from Google.

  • The base price for an off-the-shelf 2000 Watt Complete Grid-Tied DIY AC Solar Kit [] is $4600.

    The kit includes eight 8 x 8 x 5 inch Enphase inverters weighing 6 lbs each. Retailing for about $150 each. All offers for Enphase M215 Micro-Inverter []

    • The kit includes eight 8 x 8 x 5 inch Enphase inverters weighing 6 lbs each

      Which gives a power density of 0.78 watts per cubic inch. The Google challenge calls for a minimum power density of 50 watts per cubic inch.

  • I have a truly marvelous design for a kilowatt-scale power inverter which unfortunately this comment box is too narrow to contain...
  • The start up I work for practically has this product to a T. The only design spec's we don't match are the 40 in^3 (we are slightly larger, but smaller than a briefcase) and the output voltage (we do 480V 3-phase rather than 240 single). Otherwise (power density, harmonics, ability to handle loads, etc.) we've got covered. This isn't a ploy, but if anyone is interested in what we do (10 person team, solar inverter manufacturer in silicon valley) check out
  • As an actual product available right now, there's this 250 watt inverter. [] from Enphase, intended to work with one solar panel. That's 54 cubic inches, or 12W/cubic inch. Google wants 50W/cubic inch, so Google is asking for 4x the power density. This one happens to be configured for 48VDC input, but that's not hard to change. It exceeds the efficiency limit set by Google.

    Enphase sells those little inverters for a one-inverter-per-solar-panel system, where power is combined on the AC side. The inverter, a

  • by dutchwhizzman ( 817898 ) on Wednesday July 23, 2014 @02:03AM (#47513391)
    Please Google, educate the people and use metric specifications in your projects and requirements
    • by Trepidity ( 597 )

      American engineering tends to use US-customary units. Scientific research mostly uses metric, but engineering uses mostly US-customary, somewhat varying by field (e.g. medical devices tend to use metric).

      Interestingly it's so ingrained into a lot of aspects of North American production that even Canada, which has switched to using metric for engineering, has a lot of parts specified in a way that obviously refers to customary units, with things strangely coming in multiples of 25.4mm, 0.454kg, and the like.

We can found no scientific discipline, nor a healthy profession on the technical mistakes of the Department of Defense and IBM. -- Edsger Dijkstra