Google's $1M Little Box Challenge (Power inverter mini)

[Xisiqomelir]

Thermally overheat thread if old:

https://www.littleboxchallenge.com/

COOLER SIZED ISN'T COOL

Inverters are the essential boxes that take direct current from devices such as solar panels and batteries and turn it into alternating current for use in homes, businesses and cars.

The problem is household inverters are too big - roughly the size of a picnic cooler. Making them smaller would enable more solar-powered homes, more efficient distributed electrical grids, and could help bring electricity to the most remote parts of the planet.

That's where you come in: figure out how to shrink an inverter down to something smaller than a small laptop (a reduction of >10x in volume) and smaller than everyone else, and you'll win a million dollars (and help revolutionize electricity for the next century).

Learn More About Inverters

What the inverter needs to do

The winning inverter will be the one that achieves the highest power density and meeting a list of other specifications, as determined by a panel of judges, while undergoing testing for 100 hours.

In brief, the other specifications are :

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 Ω 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 60°C 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

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.

A more detailed description of the technical specifications for the inverter, the testing procedure and the requirements for technical approach and testing application can be found in this document.

How to register

The registration process is a simple form to fill out. Information must be provided in each of the fields, but any serious entry (e.g. not containing offensive material or clearly gibberish) submitted in english, regardless of approach suggested or team background, will be successful in registering. You should receive a confirmation email within three business days of your registration with a unique confirmation code.

Once registered, all the team members listed will receive updates and reminders about the prize. You must register before the registration deadline (September 30, 2014) in order to submit a technical approach and testing application and be qualified to win the prize.
Device Manufacturers

One promising set of new technologies which may allow for the achievement of higher power densities are wide bandgap (WBG) semiconductors, such as Gallium Nitride (GaN) and Silicon Carbide (SiC). Below are a list of WBG device manufacturers who have made pages describing their technology, how it might enable contestants to win the competition and opportunities for obtaining some of their devices.

Is this even vaguely feasible, electrical engineering people? I took two classes for undergrad physics and that was just fooling around with Maxwell's equations, but leaping out at me like....a jumping spider is the 2kVA load in less than 40 "^3 req.

You keep patent, by the way. I got tired of transcribing the infographics.

[madd0ct0r]

hah! I think someone at EWB might have already built something that comes close

[Irbis]

That could make renewable energy than all uninformed people campaigning for "more panels/kill atom" put together. One thing that jumped at me, though, is lack of price/resource requirement. If someone presents a box made out of (for example) solid platinum with osmium and rhenium cables, will he get the prize despite his design being commercially useless?

[Gaidin]

That could make renewable energy than all uninformed people campaigning for "more panels/kill atom" put together. One thing that jumped at me, though, is lack of price/resource requirement. If someone presents a box made out of (for example) solid platinum with osmium and rhenium cables, will he get the prize despite his design being commercially useless?

Bingo. They presented a hilariously feasible project. Something any number of engineers have probably done on the back of a napkin already at a bar. The problem? You can't sell the damn thing to anybody making less than seven figures, I'd bet, if they want it that small.

But then, this is Google. This could be something like Tesla's car. We'll sell this to the upper/upper-middle class, make god knows how much, and use that to fund a way to figure out how to make it feasible for everyone else.

[Sky Captain]

I don't get why obsession with making a smaller inverter for household application where size isn't a big problem. This could be more useful for cars and boats where space is restricted, but for household application who cares if it is the size of a cooler box or small laptop, people shopping for household inverter would look at the price and specifications first, size usually would be at the bottom of a priority list.

[Me2005]

I don't get why obsession with making a smaller inverter for household application where size isn't a big problem. This could be more useful for cars and boats where space is restricted, but for household application who cares if it is the size of a cooler box or small laptop, people shopping for household inverter would look at the price and specifications first, size usually would be at the bottom of a priority list.

This was my question as well. I have an attic *full* of absolutely nothing, I could put a huge box up there and not care. I use no fuel to move my house, so mass doesn't matter much - as long as it's light I can put it anywhere and if it's heavy I can put it in the garage or talk to an engineer about putting it elsewhere. From what I understand, a smaller unit would be more likely to fail than a larger unit, so it'd be more detrimental for me to have a small one in my house, especially if it's also going to cost much more.

Can someone explain why this is a desirable thing?

[InsaneTD]

I think it's more for homes that don't have a basement/attic. Those aren't that common here in Australia and so they tend to end up in the garage or more commonly, the laundry. Both of those are barely big enough for their primary job and adding a big piece of electronics won't help. They could also be planning on marketing the idea to places with lots of town houses. Where again, space is at a premium.

[Sky Captain]

I think it's more for homes that don't have a basement/attic. Those aren't that common here in Australia and so they tend to end up in the garage or more commonly, the laundry. Both of those are barely big enough for their primary job and adding a big piece of electronics won't help. They could also be planning on marketing the idea to places with lots of town houses. Where again, space is at a premium.

If house is so small there is no convenient place to put cooler box sized inverter then most likely roof space also is too small for useful solar array. Electronic components usually don't like to be squeezed into tiny spaces where heat removal is problematic, overheating too often can cause electronic devices to fail quickly. Size of an inverter really isn't the problem that is holding back widespread deployment of solar power. Energy storage is the main problem. Better Google would have launched competition about development of cheaper longer lasting batteries.