Google Offers a Million Bucks For a Better Inverter

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.

Comments

110 or 240v

[Anonymous Coward]

is it for generating 110v or 240v like the developed world ?

Re:110 or 240v

[Anonymous Coward]

Must be able to handle up to 2 kVA loads
Must achieve a power density of equal to or greater than 50 W/in3
Must be able to handle loads with power factors from 0.7–1, leading and lagging in an islanded mode
Must be in a rectangular metal enclosure of no more than 40 in3
Will be taking in 450 V DC power in series with a 10 resistor
Must output 240 V, 60 Hz AC single phase power
Must have a total harmonic distortion + noise on both voltage and current of 5%
Must have an input ripple current of 20%
Must have an input ripple voltage of 3%
Must have a DC-AC efficiency of greater than 95%
Must maintain a temperature of no more than 60C during operation everywhere on the outside of the device that can be touched.
Must conform to Electromagnetic Compliance standards as set out in FCC Part 15 B
Can not use any external source of cooling (e.g. water) other than air
Does not require galvanic isolation

Re:110 or 240v

[Anonymous Coward]

I have a great inverter design I just need to add 5% of harmonic distortion and noise on both voltage and current.

Re:110 or 240v

[Anaerin]

Why on earth would they call for 240V 60Hz? (almost) Nobody uses that. It's either 110V 60Hz (North America and colonies) or 240V 50Hz (UK, Europe and similar). And inverting to single phase is a lot harder than to 3-phase (and a lot less efficient).

Re:110 or 240v

[SuricouRaven]

The US does run 220(ish)V 60Hz for heavy loads. Really big appliances and light industrial.

Re:110 or 240v

[Anaerin]

Yes, because the US cheats and uses 220 split-phase to provide 110 power. Most everywhere else that needs high power uses 3-phase, as it's smoother, easier to produce and rectify, and just as safe to transmit.

Re:110 or 240v

[tlhIngan]

Except it requires more wires. 220/240V split phase requires 3 wires.

3-phase generally requires 4.

And unless you really need 3-phase, split phase is easier to deal with - with 3-phase you need to monitor all three phases to ensure they are working (failure of one phase is a common failure mode that requires immediate shutdown of the other two phases lest any dangerous currents develop).

Though, one thing I don't get about this challenge - they're using they want 2kVA output, but then demanding 50W/in^3 with a max size of 40in^3, meaning you have to provide 2000W.

And 2000W can mean providing way more than 2000VA. (The reason we use VA for inverters instead of watts is VA captures virtual power. 2000VA requires just as much power handling components (transformers, transistors, etc) as supplying 2000W at a 1.0PF (i.e., all resistive). Even if you have a really bad power factor and your real power draw is only 1000W - the hardware has to be able to instanteously supply the current and voltage for 2000W at periods in the cycle. The virtual power is virtual, because it's "given back" during another part of the cycle, but that means all the equipment has to handle it.

A lot of electric companies will have a power factor surcharge because of it - if your power factor can't be corrected to within limits, they charge more because they have to install bigger equipment.

The only real saving grace is that the input voltage is 450VDC, so you're really just doing a buck converter.

Re:110 or 240v

[timeOday]

Why on earth would they call for 240V 60Hz? (almost) Nobody uses that.

Whoah, google spent $7,300,000,000 on data centers last year and doesn't even know what voltage they run on? Time to sell my stock!

Google built its business by developing its own infrastructure, starting with custom servers in pizza boxes and lego. What crazy company runs out and develops its own filesystem for its own internal use? Google did.

Re:110 or 240v

[Anaerin]

3 Phase doesn't require the return neutral, unless your load is very unbalanced. So they both require 3 wires to transmit.

And yes, it does appear to be a simple buck converter. Though you could probably use a Z-Source inverter too.

Re:110 or 240v

[jcochran]

The 240V 60Hz is so that it can handle both North American and UK voltage levels. If you look at the technical specifications document, you'll see that there are 2 different grounding configurations that the contestants may specify. In both configurations the inverter output is fed into an isolation transformer. One specification has the input of the isolation transformer center tapped and grounded which makes the AC outputs from the inverter swing +/- 120V from ground like you would expect in the USA. The other configuration doesn't have a center tapped transformer, but one leg of the input is grounded making one of the AC outputs swing +/- 240 V in referenced to ground and the other output is tied to ground. I suspect the 60Hz specification is due to the way transformers work. A transformer designed to operate at 50Hz using minimal materials will operate fine at 60Hz. However a transformer designed to operate at 60Hz using minimal materials will saturate magnetically at 50Hz causing it to overheat and eventually fail.

Re:110 or 240v

[Charliemopps]

Yes, because the US cheats and uses 220 split-phase to provide 110 power. Most everywhere else that needs high power uses 3-phase, as it's smoother, easier to produce and rectify, and just as safe to transmit.

3 phase makes electric motors more efficient, and that's it. Technically, you could have as many phases as you could imagine having... each making the motor a tad more efficient. But they are not "smoother" and don't improve transmission.

'Phase' is often considered by some to be some magic property of electricity that somehow makes it better... it's not at all. It's a purely mechanical feature that's revolves around generators and motors. 2 phase means there are 2 electro magnets on the motor. 1 to the north, 1 to the south. When the North magnet is near and electro magnet that magnet goes to +120v and by contrast the south is at -120v. When you have 3 phase it increases efficiency by having an extra electro magnet. So now north is at +120v, but there are now 2 electro magnets to the south that are both 1/3rd of the way from that south pole and therefor at -60v each... It's a purely mechanical distinction and has no affect on anything other than the mechanical operation of motors.

Oh yea, and you can get 3 phase in the US. I got it, and most welding/milling shops have it as well.

Re:110 or 240v

[Charliemopps]

3 phase requires the return by code. Technically however, you are correct. That's just for safety and I often question if it makes any sense myself.

Re:110 or 240v

[sjames]

220v is mostly in single or duplex residential settings. Otherwise, it's often 208v (convieniantly available by connecting to two phases of 3 phase power).

Re: 110 or 240v

[Anonymous Coward]

Yeah, but if you add all three phases at any point in time, you get 1, which means constant torque. Isn't that the case?

Re:110 or 240v

[sjames]

Actually, we generate 3 phase just like everyone else. We just don't run all three to each house. Industrial and commercial users do commonly get 3 phase.

Re:110 or 240v

[Anaerin]

Yes, because the US cheats and uses 220 split-phase to provide 110 power. Most everywhere else that needs high power uses 3-phase, as it's smoother, easier to produce and rectify, and just as safe to transmit.

3 phase makes electric motors more efficient, and that's it. Technically, you could have as many phases as you could imagine having... each making the motor a tad more efficient. But they are not "smoother" and don't improve transmission.

3-Phase AC produces a smoother (considerably less ripple) DC current pattern when rectified than single or split-phase AC.

Re:110 or 240v

[cheese_boy]

Though, one thing I don't get about this challenge - they're using they want 2kVA output, but then demanding 50W/in^3 with a max size of 40in^3, meaning you have to provide 2000W.

What is it you don't get?
Requirements are >=50W/in^3 and &lt= 40in^3.
I would expect some of the entrants will exceed those requirements - doing more W/in^3 and/or less space.

Re:110 or 240v

[NotQuiteReal]

Heh, once, in a pinch, I have made due with a "special" extension cord - with two 3 prong 110 heads spliced onto a 220 socket... All I had to do was find two outlets on different phases and I was in business ;-)

Don't worry, I cut it up when I was done.

Re:110 or 240v

[Anonymous Coward]

since when is the UK at 60Hz? also a transformer may run hotter at 60Hz and even if it runs OK other components may not

Re:110 or 240v

[LinuxIsGarbage]

3 phase requires the return by code. Technically however, you are correct. That's just for safety and I often question if it makes any sense myself.

In an industrial settings I deal with a lot of loads that are three phase L1, L2, L3 + safety ground only (shield on cable, chassis on machine). No Neutral. Even 4160V loads. Unbalanced loads are brought back through L1, L2, L3.

Re:110 or 240v

[LinuxIsGarbage]

Yes, because the US cheats and uses 220 split-phase to provide 110 power. Most everywhere else that needs high power uses 3-phase, as it's smoother, easier to produce and rectify, and just as safe to transmit.

3 phase makes electric motors more efficient, and that's it. Technically, you could have as many phases as you could imagine having... each making the motor a tad more efficient. But they are not "smoother" and don't improve transmission.

3-Phase AC produces a smoother (considerably less ripple) DC current pattern when rectified than single or split-phase AC.

I've seen 3 phase 700V+ DC drives at over 1000kW that are very harmonic rich. Over 100% THD. Not smooth AT ALL.

Re:110 or 240v

[Anonymous Coward]

Actually, 240V 60 Hz, is what North America uses on their transmission lines to connect businesses/homes. For most homes, they will have 240V and 200 A being brought in. But, it will then be split into 240 and 120 V. And yes, north America uses 1150-120V, not 110.

And that is why this is a CONTEST. It IS difficult. BUT, if done right, it will mean that one company will have millions of $ in sales.

Re:110 or 240v

[evanbd]

They're fairly clear that they want the ability to provide both 2kVA and 2kW. Presumably that implies you only have to be able to deliver 2kW into a resistive load, and that if they present a load with power factor 0.7, you need to be able to provide it with 1400W and 2kVA.

Re:110 or 240v

[chipperdog]

The number of conductors needed for three phase depend on if you are delta or wye connected...

Re:110 or 240v

[jlb.think]

Exactly. I live in rural farm country, and I work on irrigation so everyday I drive by a hundred or more 3 phase motors used to pump water. A couple times a week I'm installing 3-phase motors and control panels. There is three phase equipment all over this country.

Re:110 or 240v

[thebigmacd]

It's pretty pointless to hook a neutral up to a delta-wired motor, code or no :D

3-phase 4-wire feeds are used all the time for commercial power here in Canada. Either 208V or 600V depending on what is required. Single phases are circuited off for 208V/120V or 347V single-phase feeds, respectively. A neutral conductor is definitely required for this application, yes. 208V single-phase circuits don't use a neutral, since they use two of three phases as if they were single phase. Their "split neutral" would be ~60V with respect to ground.

Re:110 or 240v

[Khyber]

Just about anything apartment-wise after the 80s uses split phase 240RMS/277 typical peak.

Re:110 or 240v

[Khyber]

Just about any component after the transformer will work fine, frequency independent, minus things like oscillators, radio crystals, etc. resistors DGAF, caps DGAF as long as you match or are lower than its rated voltage, diodes are voltage drops and DGAF about frequency...

Do you even basic electronics?

Re:110 or 240v

[Anonymous Coward]

But many components will be ok. It is why you can find foreign plug adapters with a built in transformer that will change the voltage but not do anything about frequency. In this case at least, a 60 Hz transformer is slightly smaller than a 50 Hz one (which is why airplanes will use 400 Hz).

Re: 110 or 240v

[inasity_rules]

A DC drive is generally variable voltage/current and switched through a scr. At full power, they would be smoother. At low power, the switching frequency will cause severe ripple. 3 phase is better for simple rectifiers and is indeed smoother.

Re:110 or 240v

[Anonymous Coward]

Do you even basic electronics?

Do you even basic english?

Re:110 or 240v

[Anonymous Coward]

Must have an input ripple current of < 20%

I assume they mean "must be able to handle input ripple current up to 20%" and "must be able to handle input ripple voltage up to 3%" because those are in the hands of the lab's 450V DC test supply powering the inverter.

Re:110 or 240v

[PPH]

In both configurations the inverter output is fed into an isolation transformer.

Which is going to be bigger and heavier than the inverter module. And have higher losses as well.

So what was the point of this contest?

Re:110 or 240v

[evilviper]

Must be able to handle loads with power factors from 0.7â"1, leading and lagging in an islanded mode
Must be in a rectangular metal enclosure of no more than 40 in3
Will be taking in 450 V DC power in series with a 10 resistor
Must output 240 V, 60 Hz AC single phase power
Must have a total harmonic distortion + noise on both voltage and current of 5%

It seems contradictory that they're worried about power factor, and also want to force contestants to output nice clean sine waves. Best way to get a PF of 1.0 with cheap switching power supplies, is to send them a square wave... Sucks for induction motors, but works for most everything else, including motors with brushes.

And with a simple 450VDC input you could split it over multiple circuits in series, through requiring some legwork to boost it to the exact voltage, and even it out across circuits with different load-levels, but far less than running it all through a transformer.

Such a device could be extremely efficient. I wonder what their needs are, that such a device isn't sufficient.

Re:110 or 240v

[Anonymous Coward]

Thanks for the laugh dear AC

Re:110 or 240v

[Anonymous Coward]

Do /you/ even basic English?

Re:110 or 240v

[Anonymous Coward]

If you were going to feed it into something that was just going to rectify it again and use DC, than a lot of the specs they give don't matter. However, just about anything electromechanical is potentially going to have problems. There are still lots of things around using motors, and depending on the load, running a 50 Hz motor on 60 Hz can significantly increase the current draw, and could cause problems with the start up circuit switching out too quickly.

Re:110 or 240v

[LoRdTAW]

"And unless you really need 3-phase, split phase is easier to deal with - with 3-phase you need to monitor all three phases to ensure they are working (failure of one phase is a common failure mode that requires immediate shutdown of the other two phases lest any dangerous currents develop)."

Losing a phase will not result in dangerous currents in the supply system. The most common three phase load is a motor. If you start a three phase motor and remove one of the phases the motor will continue to run on a single phase BUT it will try to draw more current to compensate for the loss of the phase. You now have overloaded windings and the motor will quickly burn itself out. You use phase protection relays on your motors to open the contactor when a phase loss is detected. So you only need to protect your motors.

A DC power supply that runs on three phase won't be affected much but the bridge rectifier can be overloaded and output ripple will increase. It will also attempt to pull more current through the remaining phase and blow a fuse or breaker. So again, its only dangerous to the load. If a 3 phase heater loses a phase, then guess what? You get less heat. That's it. Resistive heater loads can tolerate a phase loss with zero electrical problems. Your process will be affected but thats about it.

A three phase alternator does not care what the load balance on any of its phases is as long as they aren't overloaded. Same goes for a transformer. Many homes are ran off of a three phase 120/208 Y (sometimes spelled wye). Homes still get single phase 120/208 but are connected to the supply (phases A, B, C and Neutral) as follows:
A-N-B
B-N-C
C-N-A

The split is repeated for homes and they balance out the grid nicely. Splitting each of the three high voltage legs from a feeder into a neighborhood and stepping it down using center tapped 120/240 transformers makes balancing a problem. You can't interconnect any of the three separate 120/240 lines as the neutral or center taps must be grounded. Now you have 3 sets of 3 wires to deal with and you have to ensure you even distribute loads across three separate 120/240 supplies. Are you going to run 7-9 wires down a block to balance out that mess? No, of course not. So now you have individual blocks of 120/240 which may be unevenly loaded. Three phase is much easier as three houses in a row can easily balance out a 3 phase feeder. Both systems are used in residential neighborhoods (and at random might I add) but anything new is always three phase fed.

My home in Queens NY is serviced by a 120/240 center tapped 100kVA transformer that feeds only our street from corner to corner. The neutral connects to the other poles but everyone else in the surrounding area is on three phase. The poles do have 2400/4160 three phase feeders on top so getting three phase is not an issue. How we became a 120/240 island is beyond me but it might have been a leftover from old practices, never upgraded or left alone for a specific reason. Out on long island the neighborhood I lived in for a short while has 120/240 and only a single high voltage leg running along the pole. So they have to balance out the load on the feeder side.

Re:110 or 240v

[Anonymous Coward]

Isn't that the main feed on virtually all residential structures in the US? Yes the outlets put out 110/120 (I've measured my house at 125) but that is only because the main feed is split off into 110/120s except for a few high draw circuits (Electric Dryer, AC). I would assume that the intent here is to allow for better solar/wind integration into homes. Current inverters are quite large, I've seen some setups that take up more space than an entire water system (softener, heater & pressure tank). Shrink all that down to something that can fit on the side of your house like a telco box and it would probably make integration far cheaper.

Re:110 or 240v

[kilodelta]

Actually where I live it's 250V split to 125V sides.

Re:110 or 240v

[drinkypoo]

It seems contradictory that they're worried about power factor, and also want to force contestants to output nice clean sine waves. Best way to get a PF of 1.0 with cheap switching power supplies, is to send them a square wave...

The challenge is a challenge. The goal is clearly to produce usable power, not to need more filtering. While the requirements for this contest don't require grid-tie, that's something that can be implemented later.

Re:110 or 240v

[nefus]

Heh, once, in a pinch, I have made due with a "special" extension cord - with two 3 prong 110 heads spliced onto a 220 socket... All I had to do was find two outlets on different phases and I was in business ;-) Don't worry, I cut it up when I was done.

Ridgid and other brands sell cords that split 220 into 110. They are made to be used with their generators and work like a charm. No need to cut them up after you are done. :-)

Re:110 or 240v

[evilviper]

The goal is clearly to produce usable power, not to need more filtering.

You don't need to do more filtering. Most devices will run BETTER on square wave output than on sine wave output.

Re:110 or 240v

[nmr_andrew]

True enough, but if I'm reading correct, OP was talking about the exact opposite - combining a pair of 110 feeds to get 220. For "normal" US household service, incoming is 220V, and any 110V circuit simply uses just one of the two legs, so you'll typically have roughly half of your outlets using each leg.

Re:110 or 240v

[guruevi]

Check your house's breaker box. Most likely you DO have 240V/60Hz coming in. And with any digital inverter worth it's salt, 50Hz is just a matter of a jumper or switch.

Re:110 or 240v

[omnichad]

I think their use of the term islanded may refer to more than just the technical specifications. I bet Google wants this tech for off-shore floating data centers.

Re:110 or 240v

[omnichad]

Those are distribution lines. And only the drop to the customer carries 240V. That's converted down from about 2-4KV at the pole transformer off the distribution line.

Transmission lines are what connect distribution areas to generating plants and carry tens of thousands of volts.

Re:110 or 240v

[surd1618]

These different patterns all exist for motors. 3-phase simplifies the design and deployment of induction motors used in industry. That is all. There's not a substantial difference between the efficiency or simplicity of various AC output formats. The various phases exist for historical reasons.

I dunno

[Anonymous Coward]

I just use a good old 74LS06, doesn't need a kilowatt.

Re:I dunno

[mark-t]

That'd be a logic inverter, while they specifially say power inverter.

Re:I dunno

[Anonymous Coward]

Guess I wasn't as funny as I thought.

Re:I dunno

[mark-t]

It might have been funny if they hadn't used the specific terminology, thereby playing on the ambiguity of the term.

Re:I dunno

[Anonymous Coward]

But I did, look at the title. The humor derives from a kilowatt 74LS06. I suppose you could, for a nanosecond. Or maybe with klystrons.

Re:I dunno

[arglebargle_xiv]

That'd be a logic inverter, while they specifially say power inverter.

So you use it to drive an NPN transistor in common-emitter mode, say a 2N6338.

"to not look inside the box"

[fche]

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

Re: "to not look inside the box"

[Anonymous Coward]

Like a bomb.

Re:"to not look inside the box"

[Penguinisto]

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

...more like an awesome way for Google to grab a profitable patent in exchange for the prize money.

Seriously - if you can pop those kind of specifications, you can make a hell of a lot more than a million bucks from the patent alone.

Re:"to not look inside the box"

[Anonymous Coward]

Unless you already have a couple of millions to defend the patent with the large companies are just going to roll you in court and then use it for free.
Even if you have the money to defend it you can't capitalize on it yourself because your invention infringes on a couple of hundred of their patents.

Re:"to not look inside the box"

[Anonymous Coward]

Piffle. The worst they could find in that little box is... something already patented.

Re:"to not look inside the box"

[Actually, I do RTFA]

more like an awesome way for Google to grab a profitable patent in exchange for the prize money.

Except they are not claiming any of the IP, just a 100 hr license to use it for the test. Also, why they claim they will not open the box up.

Re: "to not look inside the box"

[viperidaenz]

a very small bomb.
at 50W/in2 a 2kW inverter is only 40in3. Thats a cube Less than 3.5in. About the volume of 2 cans of coke.

Re:"to not look inside the box"

[viperidaenz]

If you've got a patent for it, you just let everyone use it for 15 years then sue them all for billions in damages.

Isn't that how patents work?

Re: "to not look inside the box"

[Anonymous Coward]

I read that as 40" per side...

Re: "to not look inside the box"

[Anonymous Coward]

Yes, he should have used a ^, but you're still a fucking moron.

Re:"to not look inside the box"

[Khyber]

" Also, why they claim they will not open the box up."

And I would ask that I be allowed to personally observe my box during the entire time, if need be, to ensure that. That is all under the assumption I had such a device. I've seen it from AC-DC for LED drivers, but not that kind of efficiency in reverse.

Re: "to not look inside the box"

[Anonymous Coward]

So about room for 2 hand grenades then, enough to kill everyone within a significant radius.

Re:"to not look inside the box"

[Anonymous Coward]

There's an even easier way: a bike. Or your feet. They didn't have gates or external security when I visited.

Re:"to not look inside the box"

[Anonymous Coward]

Not sure if joke or how the real world works.

I pick (C) all of the above.

Re:"to not look inside the box"

[Actually, I do RTFA]

I'm not sure what I would do to protect my device (I'm not smart enough to make a device, so it's a moot point)

But I do know that it would be a toss up between trying to keep Google from opening the box, and trying to develop a tamper-evident prove that they did. I have no idea if the lawsuit would be worth enough to justify the costs... and whether I could patent it anyway.

Re:"to not look inside the box"

[lucien86]

If you could really achieve the stated efficiency then the value might be billions not millions. As for the patenting I would expect a budget of several or ten million just as a starting point. With the biggest players like Google or I am thinking Apple even ten million probably wouldn't be enough. That's how the patent trolls work - bottomless pockets..

I've heard this one...

[roc97007]

...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.

Re: I've heard this one...

[YodaDaCoda]

That would be a rectifier. Google wants an inverter.

Re:I've heard this one...

[geekoid]

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:I've heard this one...

[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...

Re: I've heard this one...

[ArcadeMan]

Just reverse the wires.

Re: I've heard this one...

[Anonymous Coward]

Illustrating the point of why it's important to look in the box, the ex. itself is arbitrary, stop being pedantic

Re:I've heard this one...

[Anonymous Coward]

A few years ago the EPA's EnergyStar program certified a gasoline powered alarm clock submitted by GAO auditors.

Re: I've heard this one...

[Ellis D. Tripp]

....120 times per second.

Re: I've heard this one...

[Anonymous Coward]

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

To fight dickery.

Re:I've heard this one...

[viperidaenz]

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.

Re:I've heard this one...

[Anonymous Coward]

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

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

Re:I've heard this one...

[Anonymous Coward]

Ok, how about a tiny generator somewhere---with enough fuel to last 100 hours, and enough power to improve outside efficiency to the required spec.

Re:I've heard this one...

[Beck_Neard]

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.

Re: I've heard this one...

[Anonymous Coward]

Just put some hamsters in there. They can take turns so they don't get too worn out.

Re:I've heard this one...

[Anonymous Coward]

An amusing image, sir. Thank you.

Re:I've heard this one...

[rtb61]

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 materials design and molecular engineering. Creating micro channel structures to conduct the electricity, interleaved between layers of high heat conductivity material. Of course doesn't matter if it is small if you use very expensive material to manufacture it, you end up defeating your own purpose, like fooling around with platinum.

Re:I've heard this one...

[afidel]

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.

Re:I've heard this one...

[viperidaenz]

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 perfectly fine and a conrod putting a hole in the side of your engine block.

Re:I've heard this one...

[viperidaenz]

They said it must be air cooled.

Re: I've heard this one...

[Khyber]

K. gimme an oscillator, variac, and an inductor.

Deuces.

Re:I've heard this one...

[PPH]

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.

Re:I've heard this one...

[Anonymous Coward]

GP knows that. GGP suggested cheating by doing energy storage instead of energy conversion.

Re:I've heard this one...

[Anonymous Coward]

50W * 100h of testing, 5kWh per cube inch (fimperial! 1098MJ/L for normal people) is simply not doable with batteries, fuel cells, capacitors or anything like that. Chemical reactions simply do not have this kind of energy density.

Re:I've heard this one...

[Anonymous Coward]

and OP is a faget, i guess

Re: I've heard this one...

[ArcadeMan]

Nah, they tried that before and the motors just keep colliding.

Re:I've heard this one...

[wvmarle]

Google requires AC output, so even if you're adding batteries in the mix, you still need to build the inverter, with even less space for your inverter part as added bonus.

Also Google provides a DC input, and a conversion efficiency. So they'll measure what goes in and what comes out. Having batteries in the box providing the power will show itself quickly there and then.

Re:I've heard this one...

[CauseBy]

Citation or it didn't happen.

Re:I've heard this one...

[geoskd]

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?

Yes, its just very difficult to get a very fast or efficient energy conversion from the laptop battery to an explosion. In order to produce efficient explosive force, chemical energy needs to be converted into heat extremely fast (milliseconds at least, nanoseconds would be better). Those laptop batteries are designed with exactly the opposite goal, so as to reduce overheating and fire risk.

Re:I've heard this one...

[Anonymous Coward]

So google is just looking for the next weapon of mass destruction... or perhaps this is just skynet looking for a means to control the human population. take your pick.

Re:I've heard this one...

[DittoBox]

GP also assumes you can convert one form of potential energy to another at or around 99+% efficiency. The rest of humanity would like to know how that works.

Re:I've heard this one...

[Anonymous Coward]

So, if you had this in a Model S, which originally has 170mi per charge, with 1000 times the capacity. You now have a car that can run for 170,000 miles without charging. You are likely to buy a new one before you have to recharge.

Re:I've heard this one...

[omnichad]

So why didn't they add a charging circuit for the battery, still meet the specs, and have it actually be useful? I have one on my computer.

Re:I've heard this one...

[omnichad]

they have not limited what the inverter is contained in

I think that would be included in the overall size.

Re:I've heard this one...

[Sockatume]

No, power density, the Google spec is for watts per unit volume. It's an extremely important specification.

Re:I've heard this one...

[lucien86]

With a battery like that. not just electric cars but planes. A battery like that would be the breakthrough rocket technology so desperately needs, and would make getting into orbit as easy as air travel, and would make manned travel to Mars and the outer planets a real possibility.

Working on fringe physics I can say that batteries with this kind of density or far higher are (theoretically) possible. All you need to do is store energy directly as a curved space time - as a gravity field. Its theoretical density is a ridiculous 9,000,000 TJ / Kg.

Re:I've heard this one...

[lucien86]

Oops lost a zero somewhere - that's 90,000,000 TJ / Kg. Before someone else corrects me.

Re:I've heard this one...

[Beck_Neard]

> 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?

You actually can make a laptop battery explode with impressive force; but it's hard to trigger the detonation. In fact, the comparison with TNT is actually a pretty good one, because if you set fire to TNT it will just smolder and burn. It needs to be set off in a very specific way. But the higher you go on the energy scale, the more precarious the thermodynamic balance becomes, and the harder it becomes to keep a substance's chemical energy on the non-shattering-steel-and-tearing-off-limbs part of the scale.

> 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.

But batteries already can and do explode - even though they are engineered not to. And at some level of energy density, a chain reaction becomes extremely hard to prevent. I agree that it might be pretty premature to talk about the characteristics of batteries made of unobtainium, but with 30x the chemical energy density of the best known sources, I think we can safely assume that you'd be nervous about having such a battery in your laptop or pocket.

Re:I've heard this one...

[Anonymous Coward]

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

That is an energy density. The thread isn't discussing the specification directly, but the comment that someone might cheat by including some energy storage inside.

Re: I've heard this one...

[imuffin]

TFA is talking about an inverter. You're talking about a battery. They're very different things.

Re:I've heard this one...

[viperidaenz]

It's hard to make a battery explode, releasing the stored energy because it has no readily available oxidiser.

TNT has a built-in oxidiser, so when it's burnt under pressure the fuel can ignite quick enough to cause a supersonic flame front.

Sure, you can make a battery explode by heating it up. But you can also make CO2 bottle explode too. The energy of the explosion isn't the burning of the any fuel, it's the release of the pressure. You might get a fireball from the battery as the chemicals burn with their new found oxygen in the atmosphere, but that's not going to be part of the explosion - it's not going to be burning faster than the speed of sound so will not create a shock wave.

Re: I've heard this one...

[viperidaenz]

GP was talking about a battery.

Opening the box, they found the power cable connected to a strain relief and the main power provided by a lead-acid battery.

Protip: Read before you post. Stops you looking like an idiot.

Imagine:

[Anonymous Coward]

Team delivers a highly efficient product that surpasses all expectations. When it's time to pay, Google says "we were kidding.. you must not get American humor".

Why?

[Obfuscant]

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?

Re:Why?

[Anonymous Coward]

Smaller IS cheaper.

Re:Why?

[sribe]

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.

Re:Why?

[Hadlock]

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:Why?

[Anonymous Coward]

Google can use economies of scale and their deep industrial design bench to make it cheap to manufacture. But it can only be as cheap as it is efficient in terms of lifetime cost.

So they solicit some designs, pick the best ones, and then figure out which one is the most cost effective given what Google can bring to the table.

Re:Why?

[Anonymous Coward]

There is a good reason for the why. Several actually.

1. Small size and small heat output mean efficiency.
2. KW efficiency will likely translate directly to small scale device efficiency.
3. If its small enough, new ways of moving power could be theoretically created.

This reminds me of the packaging wars of yore. "why would you want the packaging to be lighter and smaller and cheaper?"

On the other hand, I can see some team making one of these and then at the end of the day saying "Thanks for the $1million guys!"
    "how did you do it?"
"Well, you see, its graphene wrapped around diamonds. LOL"

Re:Why?

[SuricouRaven]

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.

Re:Why?

[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 efficiency, driving down costs, and opening up new uses cases that we can’t imagine today. It also doesn’t hurt that many of these improvements could make our data centers run more safely and efficiently.
The Little Box Challenge

Re:Why?

[sribe]

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?

[viperidaenz]

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.

Re:Why?

[Firethorn]

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. ;)

Re:Why?

[Anonymous Coward]

A quick back-of-the-envelope calculation says that to carry 700A at 90C, you'd need 0000000000AWG wire -- about an inch in diameter. I believe wire of that sort is more typically called a "bus bar".

Re:Why?

[Anonymous Coward]

i've run 12v through my house. with obsessive use of a volt loss calculator, but i've done it. the cost of the cable alone would have got my a 1500w smart inverter with auto gen start but goddamit i told the other half we'd have 12v and we have 12v.

Re:Why?

[Khyber]

600? 480VDC would be fine. 5A roughly? Easy-peasy.

Re:Why?

[serbanp]

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

Re:Why?

[tlhIngan]

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. ;)

You'd end up with servers welded to the rack.

Power losses increase with the square of the current - going from 5A to 10A means your cable losses quadruple. These are known as IIR losses (or I^2R losses).

Steel (iron) is an OK conductor of electricity - not great, but OK, so you'd have large losses of energy from the chassis itself (if you thought your racks were hot, well, now imagine the rack itself emitting heat!).

And unless the servers are contacted on practically every surface evenly, point-heating will take place that will weld the chassis to the server.

In fact, that's how an electrical welder works - a low-voltage high current source is all you need. Pass that current through a steel rod and it'll heat up and melt. (You want high current - voltage doesn't really matter - IIR remember? Double the current, quadruple the power).

Heck, it's a nifty physics demonstration when you take a step down transformer that takes line voltage of 120V and step it to 1.2V - that can get you 100A easily (with only a 1A draw at the other end) and that's sufficient for a demonstration. Remember, in welding, you're really creating a dead short.

it's why big racks often do get 208V, 240V or more into them - it's much easier to use thinner cables.

Re:Why?

[Obfuscant]

1. Small size and small heat output mean efficiency.

No. Efficiency in conversion translates to efficiency. You can have a box the size of a car that is is 95% efficient. And high efficiency means low heat output, not the other way around. I can build an inverter that is 0% efficient and remains at room temperature. I usually throw them out when the efficiency drops like that.

2. KW efficiency will likely translate directly to small scale device efficiency.

There are already very efficient small scale devices.

3. If its small enough, new ways of moving power could be theoretically created.

Inverters don't move power, they convert it from one form to another. In this case, it is converting 450VDC to 240 AC true-sine-wave. It's already dealing with only "the last mile".

This reminds me of the packaging wars of yore. "why would you want the packaging to be lighter and smaller and cheaper?"

This is nothing of the sort. "Lighter smaller cheaper" packaging has effects in resource use in production and shipping and sales of every item in that packaging. Having a tiny inverter does not. There was never a "packaging war".

Re:Why?

[Obfuscant]

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

If this is intended for houses, then you certainly have sufficient space for a shoebox or larger sized inverter. I have several of them in my house -- they're called a UPS, and a couple of them are 1.5kW. I haven't spent the money or they could be larger.

This challenge turns out to be to convert 450DC into 240VAC true-sine-wave. The intent seems to be to waste time converting DC into AC so it can be converted back into the DC needed to run the electronics. A lot of the items shown in the challenge don't inherently need AC, and some of them only need AC because they were built with AC motors in them. The laptops, TVs, monitors, desk lamps, toasters, automobile, radios, coffee makers -- all can be trivially designed to use AC or DC. (In fact, the very first radios sold in the US were AC/DC. That's because the AC/DC power wars weren't over yet.)

And even the excuse that converting from one DC voltage to another is harder than AC conversions is long gone. There are so many DC/DC converters in use today that nobody can seriously argue that those conversions are anything but trivial. When all we had were linear regulators it was inefficient to lower the voltage and hard to increase it, but with switching buck and boost regulators now ubiquitous that concern is moot.

So. Other than "it is cool", I still ask "why"? This size of device would be required for portable use, perhaps in poorly developed areas, but who is going to be carrying 450DC with them and need 240AC true-sine-wave to power the microwave in their pocket?

Re:Why?

[Firethorn]

You'd end up with servers welded to the rack.

Then you're not using big enough racks!

More seriously, it's one of the reasons I suggested 600V. I'm surprised you didn't pick up on that part. I wasn't suggesting running 12V through the racks, I was suggesting running 600 VDC. Which, of course, creates it's own issues. Such as a certain amount of theft prevention, but increases turnover in techs. ;)

Re:Why?

[omnichad]

They say the same thing about web servers, too. One big one is better than lots of cheaper, smaller ones. And yet that's not how Google runs its data centers...

Feed Me

[Anonymous Coward]

Everything that can be invented has been invented!

Re:Feed Me

[Anonymous Coward]

Everything that can be inverted has been inverted!

Re:Feed Me

[Anonymous Coward]

Nom Nom Nom. Troll is fed. Troll is happy. Troll thanks you for the lulz.

so...

[serbanp]

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

Re:so...

[Anonymous Coward]

This: https://www.cobra.com/products/professional/cpi-2575 or something similar, but their talking about running household appliances off the thing. That's more like this: http://www.invertersrus.com/aims-picoglf12kw48v240vs.html

Looks like once you start crossing the 2500-3000 watt range things get bigger, faster as far as unit size per kW goes. My guess is that's the market they're targeting with this competition; home solar, wind energy, etc.

Re:so...

[caseih]

I've had good luck with the Honda suitcase inverters. They aren't particularly clean emissions-wise, but they are quiet, fuel-efficient, and produce the cleanest power of any inverter I've tried.

Re:so...

[Anonymous Coward]

you're talking about the avr in a generator?

Re:so...

[Anonymous Coward]

inverters depending on price can be 85-95% efficient, with extra advantages like idle modes etc. what google want (i think) are what we call micro inverters, they are grid tied (phase aligning) but instead of one big unit you fit into the house near your main breaker, they plug into walls near those specific panels. with the right money these things can be silent, fanless and so on. the best inverters will be pure sine wave as modified and/or square waves will cause light buzz, speaker buzz and certain motors will work too hard and overheat quicker. basically, inverters are done, old as the hills and the minor efficiency lost is far farrrr cheaper than double speccing your batteries to be 48v over 24v, or even over 12v (although economy of the array drops off over 1kw with 12v as extra controller would be needed in parallel to handle the amperage, the distance to your inverter is all that matters really)

Re:so...

[Anonymous Coward]

Well, my household system runs 24VDC from the panels to the batteries and 240 VAC inverter. It's a "true" sinewave inverter, i.e. electronically synthesised sine wave, NOT a modified square wave, it's rated at 1500 watts AC continuous, up to a 5000 watt surge (IIRC less than 10 or 15 seconds at that level), and its specification sheet claims 89 - 94% efficiency depending on load. It's pretty old (I bought it in 1996 and had to replace the control boards a few years ago), but it does the job i need it to do.

Re:so...

[Agripa]

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

The ones which accept 48 volt DC inputs are better than 95% efficient but physically larger than Google's requirements.

Re:so...

[serbanp]

Having read the actual spec, I realized that my question was stupid. Input voltage is 450V, therefore the inverter is just a full-bridge DC/DC converter

The challenge is actually perfectly doable, with the only difficult points being the size of the switching inductor and the input bulk (most likely tantalum) and output filtering (must be ceramic) capacitors. IOW, the winner will be the one with the best connections to component manufacturers.

Re:so...

[Agripa]

I think the largest problems are physical construction and heat distribution. I could certainly design and build such an inverter but the construction methods needed to achieve that form factor are outside of my prototyping capabilities. This is one of those designs where the power components need to be laid out first with an eye toward thermal management which is integrated as part of the case. Forced air cooling would help a lot but comes at a significant reduction in reliability and operating life so I would not consider it a viable option.

The input is DC so there is no need for low frequency input decoupling. Large value input and output ceramic capacitors are common in high density DC to DC converters although they can make frequency compensation tricky because of their low ESR. I doubt that would be a problem here.

Re:so...

[serbanp]

The input is DC so there is no need for low frequency input decoupling

Unfortunately, that's not true. The output is AC and the input-referred current will reflect it, i.e. will be quite high when the output reaches its highest (340V). Since the input source has an equivalent internal resistance of 10Ohm and would droop too much, some bulk capacitance is needed to provide these 120Hz current surges.

I agree with you that the design revolves around the placement of power components (capacitors, inductor, power switches and some sort of heatsinking), then the control circuitry be crammed in the spaces between them.

Re:so...

[Agripa]

Unfortunately, that's not true. The output is AC and the input-referred current will reflect it, i.e. will be quite high when the output reaches its highest (340V). Since the input source has an equivalent internal resistance of 10Ohm and would droop too much, some bulk capacitance is needed to provide these 120Hz current surges.

I should have been more specific but I agree.

There are other ways to reduce input ripple current besides capacitive decoupling. A PFC stage operating in continuous conduction mode would help and may be needed anyway because of the voltage drop across the 10 ohm source resistance. I wonder if such would take up less space than extra bulk input capacitance.

Solar power?

[crow]

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 inspired this challenge. They want a Chromebook that you leave out in the sun to recharge. Or something similar.

Or maybe they have some other crazy idea I haven't thought of yet.

Re:Solar power?

[SuricouRaven]

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.

Re:Solar power?

[freeze128]

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?

Re:Solar power?

[SJHillman]

"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?

Re:Solar power?

[crow]

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

Re:Solar power?

[brantondaveperson]

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?

Re:Solar power?

[camperdave]

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.

Re:Solar power?

[Khyber]

"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.

Re:Solar power?

[Richard_at_work]

Transmission over anything further than a few dozen metres.

Re:Solar power?

[Anonymous Coward]

but other than that theres no standard for DC power right?

$1M?

[hchaos]

If you can pull this off, I'd guess it would be worth a lot more than $1M.

Re:$1M?

[Anonymous Coward]

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. We want entrants to benefit themselves through the advancements they make in order to help grow an advanced power electronics ecosystem.

However, in the spirit of advancing this power electronics community, Google may choose to make public some or all of the teams’ high-level technical approach documents. These documents outline the key innovations used to overcome the problems which currently limit high power density in inverters. They do not need to reveal any IP. We only want to show the world what techniques are possible in creating a new generation of power electronics. More details on the requirements for this document can be found in the full terms and conditions and detailed inverter specifications for the prize.

https://www.littleboxchallenge.com/#faqs

Re:$1M?

[SJHillman]

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.

Re:$1M?

[sumdumass]

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.

And here I was

[Anonymous Coward]

planning to move as much as possible to 12V, so as to do away with converting up, then down again.

Re:And here I was

[Em Adespoton]

...but at 12V, resistance is decidedly non-futile. I presume your much as possible is in a single room, or you're going to be radiating a lot of your energy before it ever reaches your 12VDC devices. Unless you're dealing with high amperages, of course. Then the runoff, while still noticeable, will at least be a small fraction of the total.

Re:And here I was

[fuzzyfuzzyfungus]

Wiring costs can add up as well. At low voltages the amount of copper or aluminum you have to throw at the problem to get resistive losses down can be pretty significant.

Re:And here I was

[viperidaenz]

So you'd rather lose power in wires instead?

Re:And here I was

[Obfuscant]

So you'd rather lose power in wires instead?

Who cares about the wires when you're going to dissipate at least 160W from that 10 ohm resistor in series with the input, and have a 40V drop to go with it?

And explain again how you keep an input ripple of less than 3% when you will be dropping anywhere from 0 (no load) to 40 (full load) volts on that 450V input?

Re:And here I was

[viperidaenz]

The 10 ohm series resistor is to simulate loss in the wires. It's not part of the system being tested, it's part of the test setup.
In the real world an inverter has to work with a non-ideal power supply. All real power supplies have output impedance.

Input ripple is the AC component of the load. The drop across the resistor in response to the load is DC.

Forgot electrical safety

[Anonymous Coward]

Just like they forget security

fairly sure you won't meet anyone's safety requirements for clearance and creepage with 'tablet like' spacing..

If I could make such a device, why give to Google?

[Maxo-Texas]

A million dollars would be chump change.

it's 240V in USA/Canada

[Chirs]

In the USA/Canada typical residential setups use two conductors at 120V to ground, but the conductors are out-of-phase so there is 240V between them.

There really isn't any such thing as 110V or 230V in the USA/Canada, both of which you'll sometimes see referenced. 208V does exist, it's the difference between two legs of a 3-phase setup where each leg is at 120V to ground.

Re:it's 240V in USA/Canada

[Khyber]

I just finished building and wiring up a full hydroponics building. You get ~277V, split-phase, and in reality, it's higher than that, because it's 120VRMS and upwards of 170V peak, so you're looking at a potential spread of 340V or more.

"There really isn't any such thing as 110V or 230V in the USA/Canada,"

From a technical standpoint, yes. From a practical standpoint, not really. RMS is good enough. Trust me, if the electronics we have were not that robust, they'd have been fried long ago. Hooray for tolerances.

Re:it's 240V in USA/Canada

[SuricouRaven]

You get ish-voltages anyway. The grid doesn't always run exactly on spec, so you need equipment that can handle a considerable variation in input voltage.

Re:it's 240V in USA/Canada

[confused one]

it used to be 110/220V and 115/230V. Over time the voltage standard has changed. it's been 120/240V for decades now. Some very old equipment has labels for 110/220V and you'll see that referenced in newer documents where someone either doesn't know the standard or is old enough to remember when it really was 110/220V. 208V/230V/460V/480V are standard 3 phase voltages most people might interact with in the U.S. I've also seen 360V. I tend to not interact with the higher voltages like 4160.

Re:If I could make such a device, why give to Goog

[Anonymous Coward]

because you are a selfless person and to make the world a better place?

Re:If I could make such a device, why give to Goog

[Anonymous Coward]

Exactly. Only an idiot would give away such a thing for only $1 million. Sounds like it would be something that could be patented and the technology licensed for quite a lot of money.

EDITOR: Read this

[freeze128]

It's "Islanded-mode", not "islanded-more".

Re:EDITOR: Read this

[omnichad]

Freudian slip as they were thinking about using these moored to their off-shore datacenter islands.

I know this is /. but RTFA

[drinkypoo]

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

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)
Response:

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.

Re:I know this is /. but RTFA

[Anonymous Coward]

I think unfortunately this clause "Google may choose to make public some or all of the teamsâ(TM) high-level technical approach documents" does not make it a stupid objections, it means the team entering better have all their IP properly patented throughout the world or they may find they just produced free technology for someone else.

Re:I know this is /. but RTFA

[MacDork]

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.

Re:I know this is /. but RTFA

[drinkypoo]

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.

Re:I know this is /. but RTFA

[CauseBy]

I think that objection is irrelevant. It doesn't matter for whom it "works out well". What matters is if the competition successfully advances the technology. Western civilization has a pretty long history of successfully advancing technology using competitions with prizes. My favorite example is Napoleon incentivizing the invention of canned food.

Re:I know this is /. but RTFA

[omnichad]

Yep - it's called spec work:
http://www.nospec.com/

240V is fairly common

[Chirs]

240V would be used for kitchen stove/range, clothes drier, electrical heat (air and water). Some commercial cappucino machines use 240V.

A home shop could very well use 240V for a welder and any number of power tools...lathe, jointer, planer, tablesaw, mortiser, wide belt sander, dust collector, shaper, etc.

Re:240V is fairly common

[SuricouRaven]

No-one uses 240V.

The UK used to use 240V. We dropped down to 230 when the EU standardized voltage across member states.

Re:240V is fairly common

[confused one]

North America is 120 / 240V split phase. 240V is common for all large loads in homes and small businesses.

Re:240V is fairly common

[SuricouRaven]

I thought north america is 110/220. A little googling clears up the confusion: It's 120V now. It used to be 110V, long ago, and although it has now been raised to 120V many people continued to use 110V labels. It doesn't help that with such a low voltage, resistance loss is a serious issue even for the short runs within a building - so you may still see 110V at the socket, even if it's supposed to be 120V.

Re:240V is fairly common

[evilviper]

resistance loss is a serious issue even for the short runs within a building - so you may still see 110V at the socket, even if it's supposed to be 120V.

Not true. You're vastly more likely to see 130V at a socket, than ever seeing one at or below 110V. That's the actual voltage delivered near the electrical box, dropping down to 125V or so, after it has been run across a building. Rough-service bulbs in the US are designed and rated for 130V instead of 120V for just this reason... A 120V incandescent light very near an electric box can have a rather short life-span.

Re:240V is fairly common

[SuricouRaven]

So the voltage drop is so rubbish, the utilities have to overcompensate...

The country really should have just gone for 220-240 when they had the chance. It's too late now.

Re:240V is fairly common

[Anonymous Coward]

I don't know what the post you were replying to is going on about, as rough service lights at designed to be handled roughly, and a heavier duty filament that is rated for a higher voltage allows it to be banged around a lot, not because you can hook it up closer to an electrical box (Incandescent light bulb lifetimes scale as some huge power of the ratio of used power to rated power, although there efficiency goes down as a result). The only time I've see > 125 V is when helping someone who bought a very cheap generator, that could easily have been out of spec for 240 too.

If you consider standard cheap wire in a house, 14 gauge wire, at the full 15 A, you would need 60 m to get a 5 V drop each way. Unless someone is going to be cheap, runs over a couple dozen meters will use a larger wire anyway, as a 12 gauge wire lets you go now almost 100 m, and there are plenty of charts around recommending what gauge to use for long run circuits. Any house or facility that is not shoddily built won't have drop off issues. Although you could possible save a bit of money and use smaller wiring to get the same effect at 240 V. That said, while I'm not familiar with wiring requirements in other countries, I've talked to a few people who though American wiring gauge requirements were kind of small compared to the place they were from that used 240 V.

Re:240V is fairly common

[evilviper]

rough service lights at designed to be handled roughly, and a heavier duty filament that is rated for a higher voltage allows it to be banged around a lot, not because you can hook it up closer to an electrical box

False dichotomy... it's designed for BOTH purposes.

The only time I've see > 125 V is when helping someone who bought a very cheap generator, that could easily have been out of spec for 240 too.

That's your own lack of perspective. I'm an EE, I went through the training and could get an electrician's licenses if I so desired. I do electrical work on my own properties pretty often. At work I'm primarily responsible for monitoring the incoming power for our hundreds of servers at our data centers and our office server rooms, etc., and designing and ordering upgrades as they are needed. I also have friends who are licensed and working electricians with lots of experience. etc.

I just tested the wall outlets in my nice new apartment, a good long distance from an electrical box, and I've got 124.1V everywhere right now. That's not abnormal at all, but completely typical.

Re:240V is fairly common

[evilviper]

I forgot to mention that generators typically output over 130V, too. Since they're not going to be located INSIDE your house, they have to similarly compensate for being at the end of a long extension cord out in your back yard.

Re:240V is fairly common

[evilviper]

So the voltage drop is so rubbish, the utilities have to overcompensate...

To be clear, the voltage drop is not predominantly from too-small wiring, but from other appliances on the circuit drawing lots of power.

It's all relative. European 230V isn't even quite double the voltage of the US' ~125V, so you still get plenty of voltage drop, yourself. Someone else could come along and say 230V is rubbish, and everyone should have gone with 420V or so, when we both had the chance... Of course the US' lower voltage has the advantage in lesser risk of electrocution, too. The higher 60Hz frequency incidentally gave us better TV...

Even though the common NEMA outlets are 120V, and that's unlikely to ever change, the wall outlets don't need to for big loads... any house built in the past 50 years probably has 240V available at least the electric box, as they get 2 opposing phases of ~130V from the power company. Big appliances like electric stoves, electric water heaters, central air conditioning, and larger split-system heat pumps or large window air conditioning units, ALL are run on 240V here in the US.

Big industrial customers make up 75% of electrical demand, and they're different beasts all together. 277V (single-phase) is pretty common in US industry, particularly for lighting and what not, while big electric motors run on 3-phase 480V or so. Wherever higher voltages are beneficial, they're available.

Re:240V is fairly common

[Anonymous Coward]

I'm an EE, I went through the training and could get an electrician's licenses if I so desired. I do electrical work on my own properties pretty often.

You're not the only one with these experiences, by far. But with such an attitude, it is not worth pointing out where those experiences seem to differ.

Re:240V is fairly common

[confused one]

130V bulbs are for applications where the source is 230V 3 phase.

Re:If I could make such a device, why give to Goog

[Anonymous Coward]

Only an idiot would comment without reading the article.

Then again, I didn't actually read the article either. I read the comment slightly above yours that showed that the submissions are not given to Google; the inventor retains the IP rights. But it sure makes it easy to troll!

Time to get rid of inverters (isn't it?)

[cmeans]

I know nothing about electricity other than the fact that AC and DC are different, so feel free to mod this down.

Assuming that our DC sources of electricity are already somewhat efficient, why don't we just have other things that use that current be DC as well?

It would seem that inverters loose some "energy" in the conversion process, which is why we need this Google like X Prize to develop something more efficient...so taking them out of the equation seems like it would be a good idea.

Is it just that we're so used to designing electronics etc. to use AC, or are there other benefits? and, if so, then why not put effort into designing AC sources of electricity?

Re:Time to get rid of inverters (isn't it?)

[Anonymous Coward]

It would seem that inverters loose some "energy" in the conversion process

What do you mean by energy that isn't tight. I've heard you Republicans use that term, but I've never met any of your kind that can explain what you mean.

Re:Time to get rid of inverters (isn't it?)

[cmeans]

Thank-you for pointing out my spelling mistake.

Re:Time to get rid of inverters (isn't it?)

[vux984]

I know nothing about electricity

So you figured you'd post your suggestion on /. instead of attempting even the most cursory self-directed research. Gotcha. Laziness for the win.

Is it just that we're so used to designing electronics etc. to use AC, or are there other benefits?

Its easier to transmit long distances, at high voltages.
Its trivial to step up and down to different voltage levels via transformers. The equivalent in DC is not simple.

Mechanical AC generators are simpler and cheaper to build and maintain. And nearly all electicity is generated from mechanical sources (turbines).

Hydro and tidal are water driven turbines. Coal, wood, biomass (methane), natural gas, nuclear, even geothermal electricity are all "steam driving turbine" eleciticity generators, wind is an air driven turbine.

That leaves solar, which IS DC. Worldwide, like 0.2% of electricy is from solar.

Batteries too, are DC, but are charged nearly exclusively from AC sources.

then why not put effort into designing AC sources of electricity?

I guess so. I mean, only 99.8% of electricity comes from AC sources. Just imagine what they could do if they put some effort into designing some AC sources, right? :p

Re:Time to get rid of inverters (isn't it?)

[cmeans]

Thanks. I've learned something, and yes, this was much easier than Googling. Now I just have to Google to find out if you're blowing smoke up my kilt or not.

But, seriously....thanks!

Re:Time to get rid of inverters (isn't it?)

[Anonymous Coward]

Its easier to transmit long distances, at high voltages.

For long distances, DC is easier to transmit because it only has to be designed for the RMS voltage instead of the peak voltage. This is especially important for underground cables, where you would also have to worry about much higher capacitance too. But even for above ground cables, very high voltage lines are limited by corona discharge, and DC will gain you an extra sqrt(2) roughly. AC isn't about transmission easy, it is all about transformers and mechanical systems.

Re:Time to get rid of inverters (isn't it?)

[Anonymous Coward]

That was a dickhead intro but very good on the rest. Quite a few of us probably learned something.

Re:Time to get rid of inverters (isn't it?)

[vux984]

AC isn't about transmission easy, it is all about transformers and mechanical systems.

I guess it would be more correct to say that AC is easier to transmit *because* of the relative simplicity of transformers at the end points.

Re:Time to get rid of inverters (isn't it?)

[Anonymous Coward]

In that sense, it depends on the situation then. Long distance transmission lines use HVDC because the conversion cost is fixed by the gains for using DC instead of AC scales with distance. The conversion costs continue to come down, so the systems that use this will become more and more common.

Re:Time to get rid of inverters (isn't it?)

[fisted]

So what's the RMS Voltage of a (say) 1000 kV DC line? Are you sure you're not confusing DC with AC?

Re:Time to get rid of inverters (isn't it?)

[Anonymous Coward]

So what's the RMS Voltage

Well, he gets pretty amped up about Ubuntu...

Re:Time to get rid of inverters (isn't it?)

[Anonymous Coward]

The RMS voltage of a 1000 kV DC line is 1000 kV...

If you tried to transmit the same power using AC, you would need ~1400 kV peak which will need more insulation distance and cause a crap ton of more corona discharge in overhead lines.

Re:Time to get rid of inverters (isn't it?)

[evilviper]

Assuming that our DC sources of electricity are already somewhat efficient, why don't we just have other things that use that current be DC as well?

It's not AC vs DC. Somewhere along the way, your input voltage won't match your output voltage, and conversion is needed. That voltage conversion is where the expensive equipment and losses come in. Adding a DC to AC step in there, adds very nominal losses to above voltage conversion step.

Since the world standardized on AC power over a century ago, it's as good of an output option as any other.

Re:If I could make such a device, why give to Goog

[Anonymous Coward]

If that is the case, stay as far as you can away from Google (and Apple, Samsung and Microsoft).

mod parent up & read it before you post idiocy

[Anonymous Coward]

n/t

Re:If I could make such a device, why give to Goog

[Maxo-Texas]

Apparently on RTF, it says that the inventor retains IP rights.

IN that case.. never mind. :)

black box cheat

[Anonymous Coward]

My "inverter" contains a plutonium RTG.

I don't understand the problem here.

[westlake]

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

Re:I don't understand the problem here.

[Carnildo]

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.

Re:I don't understand the problem here.

[Archangel Michael]

Just design it to be 64.1 times more dense. I'm not an electrical engineer, but i would think a little advanced materials application should move the ball at least half way towards to goal, and I'm sure that there is already non-commercially viable means to do just that. Applying engineering to get the rest of the way should push the cost of the first half down further.

Unless someone is pushing the ball, progress may stall. I see this as Google pushing the ball, and that by itself might be worth it.

Re:I don't understand the problem here.

[Anonymous Coward]

Heat density.

I have a truly

[fisted]

I have a truly marvelous design for a kilowatt-scale power inverter which unfortunately this comment box is too narrow to contain...

Kittens?

[Anonymous Coward]

Can I use kittens in my design?

Re:Kittens?

[Anonymous Coward]

Does it output pop tarts, with the electricity as a side effect?

Re:Kittens?

[lgw]

Can I use kittens in my design?

Yes, as long as they fit in the box (so you're likely limited to 1 kitten), and as long as they're not water cooled kittens.

Re:Kittens?

[fbartho]

Also, Google gets to keep the boxes for over 100 hours, and you'll only be guaranteed to have power for 100 of those hours, and they make no guarantee of the storage conditions when it's not being tested, so if you want to have a living kitten at the end of it, you may need to do a lot of work.

Everything but the 40 in^3

[tesla_reincarnated]

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 www.HiQSolar.com

About 4x beyond current production.

[Animats]

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, at 171 mm x 173 mm x 30 mm, is a lot smaller than the panel it sits behind. Making it smaller won't have any effect on system size.

One big difference: Enphase offers a 25 year warranty on that unit. Google only wants to run for 100 hours. They'll probably get something that will pass their tests but wouldn't last a year in a real solar installation.

Re:About 4x beyond current production.

[Anonymous Coward]

Longevity is a solvable problem from an engineering standpoint. It might be expensive, but should be solvable.

A good working knowledge of your components is required, and the knowhow to ensure they are all being operated within their tolerance. (And the knowhow to over-spec critical devices in the event of a worse-than-worst-case scenario)

Of course, you might end up with a case where your project exceeds the tolerances of any readily available (Or economically viable) components, in which case your project is a failure.

Re:About 4x beyond current production.

[Anonymous Coward]

They'll probably get something that will pass their tests but wouldn't last a year in a real solar installation.

That would be perfect for them then as most google devices don't last a year either.

Re:About 4x beyond current production.

[Anonymous Coward]

Actually their demand is by far surpassed by the AMSC PM3000 series, actually one of this units hardware wise unmodified and run to mach the Google specs obtains the 50W/cubic inch, the unit redesigned can reach the 120w/cubic inch without problems.

Re:About 4x beyond current production.

[PTBarnum]

I looked at http://www.amsc.com/pdf/PM3000...

The spec sheet claims "power density of up to 130 W/in. (7.9 W/cm)"

But I also see:
Dimensions 38.2in*19.8in*18.7in = 14100 in^3
AC Power 690V * 750A = 520000 VA
Density: 37 VA/in^3 (also an upper bound on W/in^3)

What is the justification for the 130 W/in^3 claim?

Seems odd

[Anonymous Coward]

The people who should have already figured this out are the people sponsoring the event. Seriously, what backyard engineer is going to have the resources to design and prototype this thing? A million bucks would be a drop in the pan for the present commercial manufacturers, little incentive to reinvent their products. I see this going nowhere.

Who gets the prize when several teams meet spec?

[sberge]

Couldn't find the answer on the site. May be blind.

I have a truly

[Anonymous Coward]

is your name Galois?

I've heard this one...

[Anonymous Coward]

If someone makes a battery with associated inverter that does 2kVA for 100 hours per the spec, then it still exceeds the inverter spec they wanted (since you'd need that to get the power output from the battery anyways, that's kinda the point of this challenge), and you also have a battery that holds 200-300 times the energy of the latest battery (assuming you draw no input). Google would be happy to pay you $1mil for that thing, hell you could probably get $100mil for that.

They picked a power density that is very high, and the challenge is targeted at solar for the home, there isn't really anyway you can cheat without first solving the problem.

Eric Raymond as Google blog poster?

[Anonymous Coward]

It was posted to the google blog by Eric Raymond. The one from "Cathedral versus the Bazaar" fame? I think so... cool!

College kids created Google, Microsoft, Facebook

[raymorris]

A few friends who are electrical engineering majors certainly might achieve this. After all, it was a small group of college kids who created Google, Microsoft, and Facebook. On the other hand, 10 Google employees sitting in meetings to discuss the requirements document costs over $2,000 / hour once you factor in taxes and such. A million dollars is enough to motivate some ramen-eating college kids, and small enough that it's not much more than the cost of paperwork and approvals for many projects at large companies.

Weird restrictions

[rover42]

They exclude people in various places from entering. https://www.littleboxchallenge... I can see why Cuba, Iran, N Korea, Syria & Sudan are listed. But why on Earth are Brazil, Italy & Quebec on the list?

Re:Weird restrictions

[50000BTU_barbecue]

Quebec is a ridiculous backwater corrupt banana republic with a monstrous, bloated bureaucracy that not even Google can deal with.

Re:Weird restrictions

[Anonymous Coward]

Quebec is easy, Google doesn't want to provide the contest requirements in French.

Brazil, I'll guess because they don't want to add cane ethanol to it.

Italy? I dunno, no money for bribes to the the Pope?

Re:Weird restrictions

[Anonymous Coward]

It is often difficult to poke holes in an argument that is so well presented, however, you did miss the fact that Google has an office in Quebec.

http://www.google.com/about/careers/locations/montreal/

Re:Weird restrictions

[50000BTU_barbecue]

Yes, wonderful, how does that mean Google can handle the bureaucracy for this contest?

Please do show me the quality of your argument. You know, since I live in this shithole and everything.

Re:Weird restrictions

[Archangel Michael]

Likely it has to do with the prize laws in those locations. Goofy Laws designed to protect the population, does exactly the opposite!

Re: Hamsters?

[John.Banister]

Not enough cube. You want 9 million nanoscale exercycles powered by the souls of the damned. I dare you to open the box.

NOT What They Really Want

[Anonymous Coward]

Google doesn't want a better inverter, rather they want a means to convert Male-to-Female harassment in real time to Female-to-Male harassment that will stand Federal Judicial Review and bang-a-case in Google's favor.

Keep trying

[Anonymous Coward]

Let's tether technological advancement purely to up front cost.

Are there no savings to be had from smaller inverters with higher power density? Do you have no imagination left? Too many years kowtowing to PHBs and budgets, I expect.

We're not talking about building a colony on Pluto. There are very real advantages to improving our energy infra.

The same old repetitive question:

Why?

The answer is simple...

Because we should keep trying.

Cubic Inches?

[dutchwhizzman]

Please Google, educate the people and use metric specifications in your projects and requirements

Re:Cubic Inches?

[Trepidity]

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.

Re:Cubic Inches?

[Anonymous Coward]

Please foreigner, STFU about your shitty different arbitrary numeric constants already.

Re:Cubic Inches?

[wvmarle]

You can easily convert to more useful measures using Google.

Of course it'd have been nice had they use their own tools to advance science. Or maybe that should be: to have the US catch up with the rest of the world.

Re:Cubic Inches?

[CauseBy]

Maybe they were trying to filter out submissions from people too stupid to google "x inches in centimeters". Most engineers know how to multiply by 2.54, I think.

"...operating in an islanded more—..." WTF?

[Anonymous Coward]

"Island Mode" for Generator Operation...
"Inland Moor" for burying your enemies...
"I Landed More" for increased Air Miles...

We're saved!

[Anonymous Coward]

One million space bucks! We'll be able to pay off Pizza the Hut...

Oh wait..... It was regular bucks.... never mind then!

more HZ smaller transformer

[Anonymous Coward]

dunno if this helps but if you can up the AC cycling frequency
the transformer can be smaller ...
plasma can rectify also.
that's all. good luck!

Area 51 question.

[Anonymous Coward]

What if a team creates the solution and presents it to Google successfully, but the US federal government confiscates the device and takes the patents for itself as an item of national security importance? (This means the inventor is not even entitled to compensation!)

I am asking about this scenary, because such high power-density electric inverters already exist and they are being used in the latest generation of fighter jets (e.g. America's F-22 Raptor or Europe's Gripen NG and Eurofighter Captor). They are used in the power supply chain of onboard radars with active electronic beam-steering (AESA) antennas.

Such super-density inverters are extremely expensive, totally secret and currently require non-aquatic liquid cooling, using the plane's jet fuel as a heat transfer medium or even phase-change ammonia. (For example the Gripen NG received two new ungainly air-intake scoops to fit the extra cooling's bulky radiators.)

If a "basement-dwelling" team of geniuses invented a simple ram-air cooled equivalent, with same or better inverter performance, the "Skunk Works" guys from the "military-industrial complex" would be all over that in no time.

Not worth it to enter the contest

[Anonymous Coward]

if you design it for the contest, it becomes google's property. If I designed one, patented it, and licensed it I could earn more that $1M easily.

Why ??? do you have any idea of how much heat 50W per cubic inch produces ? Tablet size is not possible with today's technology.

I'm not an EE, but are new electrodes good enough?

[DRAGONWEEZEL]

If you could get a mechanical inverter to work for a max of 100 hrs using new electrode technologies... you should be able to make it small enough.I'm talking spin switched.

In short, My question is, electrodes are getting extremely good maximizing conduction and minimizing wear, but are they good enough to make mechanical switching a possibility?

Say funnel a MAX of say 20 amps @ 12vDC to a spin a high efficiency brushless DC motor nice and fast. The DC motor would be attached to a plate that would have a Rotating I (maybe an X?) of High tech carbon nanotube ended graphene electrodes spining in a circle. Spinning at the right frequency, it should convert the DC to square AC. Round it out, and then a computerized Vmeter + tied back to an ESC could regulate the motor's speed keeping the phase locked good n tight, minimizing fluctuations.

I'm not an EE though, I feel like there's something wrong w/ this, that the loss might be too high, or maybe that kind of electrode technology isn't there yet?
Just curious..

What is Google Up To?

[Anonymous Coward]

In general, this appears to mean that Google has an application that has access to a lot of DC power, and they need AC. Solar Panels, producing DC, and they need to power existing AC appliances in the house? "Island mode"? I'm curious to know what is producing so much DC power. If it's close to whatever needs the power, it never needs to be converted to AC. AC won out over DC in the early days of electricity because of DC's limited range of transmission. If the distance goes away, direct DC can come back. Appliances can switch over.

It doesn't make sense that it has anything to do with cars, because people tend not to use AC appliances in the car. I've always wanted a direct DC power supply to go from car power to directly powering a computer.

Maybe I'll start rewiring my house to also include some DC outlets. Seems like Google is up to something, here.

(As I post this, the "prove you're human" word is "ground". Interesting.)

Incredulous

[PJAJr]

Haven't these guys ever been to Harbor Freight?

Re:Incredulous

[Anonymous Coward]

One of the requirements is that it has to last 100 hours...

Who gets the prize when several teams meet spec?

[Anonymous Coward]

"...and the prize is reserved for the best performing entrant."

Re:College kids created Google, Microsoft, Faceboo

[Agripa]

I think the hard part in this case will be the physical design and construction to stay within the thermal constraints. Brick style power converters have power densities and efficiencies in this range but are designed to be attached to a metal surface for heat dissipation and Google's requirements do not allow for that.

Active forced air cooling would help a lot but also make long term reliability poor.

Re:College kids created Google, Microsoft, Faceboo

[Anonymous Coward]

Hardware is much more difficult (and requires deep experience) than software because it involves cold, hard physics. So script kiddies like Zuckerberg need not apply.

Your bulding is wired with 3 phase source.

[confused one]

Based on your commend, I suspect someone wired out your building in 230V 3 phase, since it's "close enough" to get away with in place of 120V/240V split phase; and, lets them put in more efficient 3 phase pumps and air conditioning systems. Some residential buildings and residential neighborhoods are wired out in 3 phase but the private residences only uses 2 of the 3 phases, except for the A/C system. Usually that's done in 208V 3 phase; but, it's conceivable someone could have put in 230V transformers.