Google $1M Contest to Make Solar, Wind More Practical

John Lister's picture

Google is teaming up with the Institute of Electrical and Electronics Engineers to try to make "green energy" more practical. It's running a million dollar contest called "Little Box Challenge" to try and reduce the size of a key component in bringing renewable power to homes and businesses.

The competition is based around the fact that electricity comes in two forms: alternating current (AC), and direct current (DC). Alternating power is used in homes and offices, with its flow of electrical charge changing direction continuously. On the other hand, direct current always flows in only one direction; an example of direct current is a car battery with positive and negative terminals.

AC/DC Power Still Relevant

Because alternating current changes the direction of the terminals at a regular pace (approximately 60 times a second in the United States), it is much easier to change voltage mid-transmission. Because of this benefit, alternating current is used to carry electricity from power plants over power lines at extremely high voltages. When it reaches homes and offices, the power can be reduced to much lower voltages.

The problem is that most smaller-scale renewable energy devices produce direct current, such as solar panels or small wind turbines. To make it suitable for everyday use, it needs to go through a device called a power inverter that switches the direct current to alternating current.

At the moment, most inverters are fairly bulky. For example, a typical power inverter for a solar panel might be the size of an ice cooler or picnic basket. That makes it much less attractive to use energy sources on a small scale, whether it be in a home, or in a portable setting such as a car or recreation vehicle. (Source:

Google Will Fund Some Entrants

Google is now hosting the Little Box Challenge, which challenges inventors to create an inverter that is 10 times smaller than current models. That would make it smaller than most laptop computers. (Source:

Anyone can enter the contest, though Google says it expects it will be mainly businesses and university groups. It's offering some money in grant funding to academic entrants. Whoever wins the contest will keep the rights to any intellectual property involved in developing an entry and will be able to turn it into a business if they want to do so. However, Google will publish an overview of the technological approach the winner took in solving the problem.

What's Your Opinion?

Would smaller inverters make you more likely to use renewable energy? Or do you think renewable supporters need to concentrate on tackling other problems and limitations? Can you think of other ways a smaller inverter might be useful?

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Dennis Faas's picture

This would certainly help to boost green energy projects by lowering costs, but I think one the biggest hurdles of green energy - especially for home applications - is the cost of solar energy panels.

I had a solar energy company solicit me last year, wanting to put solar panels on my roof. The promise was that the government would buy back the energy at a very high locked-in rate, guaranteed for (I believe) 20 years, which is also the time it would take to pay back the cost of the installation. The project would have been in the neighborhood of $45,000 - most of which was attributed to the high price of solar panels.

Long story short, I would have needed to go to the bank and take out a mortgage just to have them put panels on my roof. Meanwhile, there was no guarantee that the installation would maintain itself / remain in a working state, nor was there any guarantee my roof wouldn't leak due to an improper installation. What if the company went out of business after the system failed? I'd be on the hook for having to pay back a loan on a defunct system. No thanks!

jamies's picture

Solar power and windpower generated electricity normally have to be 'inverted' or at least regulated to match the home supply - 240v 50cycles in UK, 120? 60 cycles in the USA.

Windpower devices are usually a bit too large to install on existing, modern city properties.
However many such buildings do have space for the sort of rotating advertisements that used to be on the pavement outside small shops - sort of like a cut-up 50 gallon drum.

Considering that most of such homes lose heat at a far greater rate when cold winds are blowing, why not make small wing driven generator devices available with an associated radiator - such as the oil filled freestanding ones sold for domestic use.

If the radiator is set to use DC supply at (say) up to 200volts, it could be connected (via a regulator) to a generator that is not going to be connected to the normal mains supply, or any other devices in the house (except, perhaps some storage batteries)

That would avoid the expense of the inverter and connection to the mains with all the annual? checking currently needed.

Simple - more cooling wind = more heating via the radiator!


Maybe something similar could be done with solar power - directly drive cooling devices so you get the sun to do the A/C


ecash's picture

A few points to ponder.
1. the corporations that control, YES CONTROL(as they dont OWN 80% of the facilities) dont like a distributed system. they dont want to SPREAD power generation around.
2. Cost? it WAS, said in the past that the corps were Buying up the Solar companies and shutting them down or Over pricing the products so no one would buy them.
3. do you know that 90% of the products in your home work off DC, power? And that MOSt power is created FROM DC, to AC to be sent..mostly because of Loss in transmission to location Farther away there is less Loss in AC..
4, if you could get Small town initiatives going, you could reduce a good share of power usage.. It is now possible for small towns to generate MOST of their own power, with only a few acres of land..Wind, Solar electric, and solar furnaces..
Much of which could be placed on taller buildings in Cities to generate power..
5. it would be an interesting idea, to set up homes for AC and DC..Stop making things for DUMB PEOPLE.

There are so many things that are PART of this, its almost overwhelming..
You COULD convert to DC powered products, but prices are about 4 times AC, for some strange reason..
Power converters, is part of the problem, but power Storage is the fun part..

I would LOVe to replace 1 WHOLE wall of my house and have it become my Storage..

nepperson's picture

It would seem there are other factors besides the size of the invertor that would curtail the use of green energy. There is Location, Size of the Solar Panels or Wind Turbine or Solar Furnace and Efficiency or Usability Percentage (How mush can you count on solar energy on a cloudy day or a day with no wind) of the system that would seem more of a concern than having an invertor the size of a notebook.

It is true that AC current dominates because you can transmit AC further with less loss due to resistance and other reasons. This method of transmission has been around for a long time and to keep it simple at the time the devices in the homes were designed to utilize the AC current without converting it. Those devices were typically Light Bulbs, Heating systems either for water or for the house, and motorized devices like Fans, Refrigerators and such. There was no technology such has what we have been accustomed to for entertainment, knowledge, or convenience. The technological devices we all love need DC power to make them operate anyway and the very first stage of any such device is the "power supply" which is a circuit to change the AC current to usable DC current. If this stage was not needed due to homes running on DC instead of AC it would be cheaper to produce the device and as this stage is often the cause of device failure due to surges and brownouts the items may even last longer.

Perhaps this is one of the ways we need to change in our thinking. Some of the AC devices such as water heaters or light bulbs will work on DC power just as good as AC (conversion factor is approximately 66 percent if I remember correctly). Other household items are already on the market (although pricier) for use in RV/Campers (or for the person that wants to be self sufficient and run devices on human power) will run on DC power . I even saw a pamphlet for a Solar Powered A/C system manufactured by Trane at my local home improvement store. If DC driven devices were mass produced in the same quantities of their AC brethren it would lower the manufacturing cost and ergo the end cost.

My thought is that homes that were designed for Green Energy normally have a method of storing the excess DC power as in a battery rack (in all likelihood). If these homes were also designed for DC current (only) it would be more efficient instead of having to convert it to AC which the "power supply" of the device would convert back to DC we could eliminate that inefficiency. There would only be one convertor needed and that would be an AC to DC convertor as a backup to use the power from the power company to recharge the Batteries or provide the DC current for the home for those cloudy or windless days

While we might not be selling power back into "the grid" without an invertor it would go a long ways to reducing our dependency on the power company. And although DC power has a limitation on how far it could travel without significant loss there could still be several homes connected to one green power system with proper planning enabling the cost of the system to be distributed among several users. Anyways, this was just my opinion on whether the invertor size was the needed improvement in green technology.