Turn your house into a giant battery.

June 29, 2012 3:17 PM

"You could turn your home into a battery," said researcher Neelam Singh. Researchers at Rice University have created paints that act as rechargeable lithium-ion batteries. They can be painted onto virtually any surface, and can be charged with a solar cell. Full paper.
posted by stoneweaver (42 comments total)

The future is wow!
posted by Renoroc at 3:24 PM on June 29, 2012

How much energy storage capacity are we talking about? If it's only a few thousand joules, it's a waste of time.
posted by Chocolate Pickle at 3:25 PM on June 29, 2012

"...could give any surface the capability to both harvest and store energy."

This is the coolest idea I've read in a long time.
posted by Greg_Ace at 3:26 PM on June 29, 2012

I totally read that as 'pants'. This is much cooler.
posted by cobaltnine at 3:27 PM on June 29, 2012

How much energy storage capacity are we talking about?

"equivalent to 6 Wh/m2" per the paper linked in the FPP, which took me only 30 seconds to find.
posted by anigbrowl at 3:31 PM on June 29, 2012 [1 favorite]

How much energy storage capacity are we talking about? If it's only a few thousand joules, it's a waste of time.

Anybody with the technical chops to parse the energy outputs described in that full paper link in the FPP? I half-tried but it just scans like meaningless electrical and materials engineering mumbo-jumbo to me.


"equivalent to 6 Wh/m2" per the paper linked in the FPP, which took me only 30 seconds to find.

Ah--on preview, thanks anigbrowl. But is that, erm, good?
posted by saulgoodman at 3:34 PM on June 29, 2012

Laptop batteries are generally between 45 and 90Wh, depending on size. If my math is right that means my garage wall is about equal to a low-power laptop battery.
posted by pupdog at 3:44 PM on June 29, 2012

But is that, erm, good?

Well, let's suppose you have a typical one story house with a simple rectangular footprint. It's 70 feet long and 30 feet wide (1400 square feet) with 9 foot walls. I assume you won't paint the roof because that's where the solar cells go, and we'll ignore windows and doors. That's 167 square meters, which gives almost exactly 1 kWh, or about 12 cents worth of electricity.
posted by jedicus at 3:44 PM on June 29, 2012

None of which answers saulgoodman's question without extra information, like: average home use in (series of countries). Googling turns up some numbers and I don't know how accurate any of them are, but they generally seem to suggest that - using jedicus' numbers - 1kWh is not a heck of a lot in a day.

Things to consider, though:

1) The paint is probably going to be more effective in certain parts of the world than others.
2) If you're in a really crappily poor place, you may not have a lot of things that need electricity anyway. (though your house is likely small and so you'll be getting even less, so I don't know)
3) This is the first iteration of the technology. Better paints might be out in five years' time.
4) The paint is probably way, way cheaper than standard solar cell installations, and will require less technical expertise to install and maintain.
posted by curious nu at 4:01 PM on June 29, 2012 [2 favorites]

The paint itself is just a battery - There will still have to be some sort of standard solar install to charge it.
posted by pupdog at 4:03 PM on June 29, 2012 [2 favorites]

That's 167 square meters, which gives almost exactly 1 kWh, or about 12 cents worth of electricity.

Hmm. That might not be very good but it's not as bad as it sounds at first either. According to this:

The EIA reports that in 2007, the average American home used 936 kilowatt-hours of electricity each month.

So assuming roughly 30 days in a month, that's around 31.2 kWh per day.
posted by saulgoodman at 4:04 PM on June 29, 2012

The paint itself is just a battery - There will still have to be some sort of standard solar install to charge it.

Reading comprehension, my old foe! We meet again.
posted by curious nu at 4:11 PM on June 29, 2012

But if you push a stainless steel cart against the wall will your kitchen explode?
posted by CynicalKnight at 4:15 PM on June 29, 2012 [3 favorites]

How much energy storage capacity are we talking about? If it's only a few thousand joules, it's a waste of time.

Yes, because technological breakthroughs generally emerge from the lab fully formed and ready for mass production. That's why even today, every school kid knows about Gottlieb Daimler's famous Model T car.
posted by gompa at 4:17 PM on June 29, 2012 [8 favorites]

It will be pretty interesting when the fine art painters start to get ahold of this stuff. The possibilities are intriguing.
posted by chaff at 4:20 PM on June 29, 2012 [2 favorites]

"...could give any surface the capability to both harvest and store energy."

This is the coolest idea I've read in a long time.

Tell that to the plants.
posted by fairmettle at 4:21 PM on June 29, 2012 [8 favorites]

Even if the capacity never got much better, you could still live a lot better than a caveman on 1 kWh of very judiciously used electricity at night. Even splurge on an hour of TV every now and then... Daytime solar capacity's no longer really a technical challenge. We could just, I don't know, sleep at night, or read books.
posted by saulgoodman at 4:23 PM on June 29, 2012 [1 favorite]

The graphite crystals in a lithium ion battery have a hard limit of approximately 900 cycles, and after that they are spent. If similar constraints apply here, what do you do, keep repainting in thicker layers? Scrape it off into a pile, and then do what with it?
posted by StickyCarpet at 4:23 PM on June 29, 2012

You could increase area by building and painting panels that are attached to a central pole, like cooling fins on electrical whatsits.

Or stack 'em up inside a wall.

Lots of possibilities...
posted by notyou at 4:27 PM on June 29, 2012 [1 favorite]

Even if the capacity never got much better, you could still live a lot better than a caveman on 1 kWh of very judiciously used electricity at night

Why is having a battery in the form of a huge painted surface better than a small compact sealed container though? It would have to be drastically better than a normal battery in some way to justify the hassle of having to paint it on stuff and dealing with all of the consequences of that (easier to damage, needs a lot of area, harder to dispose of in an environmentally safe manner, etc.). If all you need is a laptop battery's worth of electricity from your solar panels in your house then just use a laptop battery, they already exist and would be the smallest and cheapest part of your solar power system. It seems like this kind of painted-on battery technology would only have applications in situations where an existing battery wouldn't work for whatever reason.
posted by burnmp3s at 4:50 PM on June 29, 2012 [4 favorites]

Good gravy I need this like yesterday. I've got the equivalent of 12 largish car batteries charging off an inverter in my place to keep the lights on when the power drops, as it does at least twice a day in Nairobi. I would paint my entire place bright pink if it meant no longer hauling those damn batteries in and out when they need to be changed.
posted by allkindsoftime at 4:56 PM on June 29, 2012 [1 favorite]

If you overcharge it does it puff up and burst into flames? (anyone who flies RC knows about this one)
posted by smoothvirus at 5:01 PM on June 29, 2012

Why is having a battery in the form of a huge painted surface better than a small compact sealed container though?

Because everyone has painted walls, and having a little extra capacity doesn't hurt. Honestly, have we become so used to wonders? "Free food, eh? What if it is not to the liking of my individual palate?"

I would, however, like to know if the paint makes one's house a greater target for lightning strikes. I suspect that wouldn't be exactly a good way to charge one's house.
posted by JHarris at 5:07 PM on June 29, 2012 [2 favorites]

JHarris: ""Free food, eh? What if it is not to the liking of my individual palate?""

Not a great analogy. The McDonalds dollar menu is essentially free, in the grand scheme of things. Thankfully, it doesn't make up a large part of most folks' diets.

Just because you can do something does not make it a good idea. The cost of producing, installing, and connecting all this stuff is not going to be negligible, especially when compared to the cost of a battery that you could stick in the attic or basement.
posted by schmod at 5:11 PM on June 29, 2012

How is this tied to solar power in any actual way? You could just as easily recharge it through a wall socket, or use the solar cells to charge a regular lithium-ion battery.
posted by Holy Zarquon's Singing Fish at 5:31 PM on June 29, 2012

At the beginning:

However, it was not until 1883 that the first solid state photovoltaic cell was built, by Charles Fritts, who coated the semiconductor selenium with an extremely thin layer of gold to form the junctions. The device was only around 1% efficient.

Currently:

Solar cell efficiencies vary from 6% for amorphous silicon-based solar cells to 40.7% with multiple-junction research lab cells and 42.8% with multiple dies assembled into a hybrid package

So there may still be hope for this technology.

(Both quotes above from Wikipedia)
posted by troll on a pony at 5:41 PM on June 29, 2012

The obvious first step is to totally paint the Statue of Liberty an inconspicuous green, rendering her a vast thrumming copper reservoir of electric energy, and when lightning strikes her, BOOM! A living statue as American Autobot!

Next step: THE PAINTED DESERT
posted by nicebookrack at 5:50 PM on June 29, 2012 [2 favorites]

I was reading about this developing in National Geographic just a few years ago. How cool that they've come so far already. My household uses 10-12 kWh/day, and I know some folks who are entirely off the grid who use 3 kWh/day (both families of four, so fairly apples to apples).

If a house could get about 1 kWh/day of energy with this development, that's a big honking deal. Even in the Upper Midwest, you can get about 2 kWh per day from a two car garage with a standing seam solar film roof, so that could account for 25-100% of a household's electricity use, which is both huge and very achievable. This presumes conservationary measures such as those we have taken, but they all are dead simple and could be done by virtually everyone.
posted by Athene at 6:06 PM on June 29, 2012 [3 favorites]

...it's a waste of time.

Using paint for large signs, etc would cut down fossil fuel use, maybe not significantly, but are we every going to start? Every suggestion for alternate energy forms seems to get cut down at the knees. WTF, citizens? Are we going to do something about global warming or not?
posted by BlueHorse at 6:14 PM on June 29, 2012

I don't get the naysaying and the bringing in of extraneous use cases. Seems pretty obvious the vision is a place to store solar energy at night for example, when power use is down. If the numbers of 1kWh are right, then its not a lot of power but will run a TV and a fan or charge your gadgets and a number of things which are useful. Tech will get better with more research, and another small piece to puzzle may be fitted in time.
posted by sfts2 at 6:30 PM on June 29, 2012

Given that there talk about spray on solar cells that can be used on windows, the junction of the two technologies is interesting, especially as things imporve
posted by edgeways at 7:13 PM on June 29, 2012

I'm mostly worried about the safety issues: waterproofing, short circuits, protection from accidental overcharging, etc. What happens to this stuff in the event of flood, amateur with power-tools, house fire, or toddler?
posted by yeolcoatl at 7:26 PM on June 29, 2012 [1 favorite]

or about 12 cents worth of electricity.

Electricity is really astonishingly cheap, considering just how much work can be done with a kilowatt-hour, so that's maybe not the right way to measure. Rather, just realizing that your house itself can store that much power lets you, perhaps, run a small UPS for certain critical items, like maybe a cordless phone, or a network connection, or a thermostat if your climate control has some other method of powering itself.

Or maybe it could keep your refrigerator cold for an extra eight hours or so, as long as you didn't open it.

A thousand watts, for an hour straight, is a fair bit of power.
posted by Malor at 7:45 PM on June 29, 2012

Paint? Sounds gimmicky/press-releasy.

If this is a new electricity storage device, why not make like capacitors (only.. safer? higher energy density? cheaper? more stable?) and paint this on really thin ribbons/films and fold the results?

Better batteries are great. But this doesn't sound like the solution, maybe an a solution, but definitely not a major one. Unless there's some sociological/economic/legal-tax shenanigans successfully pulled off (then again; NYC has an incredible density of cabs - wouldn't economic incentives to transition that fleet into electric/-hybrid/CNG/hydrogen make a ton of sense not only in reducing the carbon footprint of NYC much less improving the quality of life by increasing air quality? The savings in medical care alone..).

The outside surface area of a 2 story standalone house could probably be folded into something into a space the size of a conventional water heater - depending on how thick the paint has to be and the thickness/flexibility of the substrate (and dried paint). Maybe much larger depending on the materials.

If you're in an ultra-high density environment, maybe increasing the size of the building marginally (by painting charge-holding material to the outside)... maybe. Depends on a ton of other factors.

Don't forget, you'll also need surface area for the proposed solar panels.
posted by porpoise at 8:09 PM on June 29, 2012

Cool that they developed a super flexible battery, I'm sure it will lead to wonderful things, but I'm not sure painting a house is one of them.
posted by deo rei at 8:14 PM on June 29, 2012

JHarris: "Because everyone has painted walls, and having a little extra capacity doesn't hurt."

On the other hand, heating walls up to 90~120°C, painting them in lithium cobalt and lithium titanium oxides, soaking them in electrolyte in an oxygen-free atmosphere, and sealing them in metallised film, is a job best left to professional painters…

deo rei: "Cool that they developed a super flexible battery, I'm sure it will lead to wonderful things, but I'm not sure painting a house is one of them."

This. The "turn your walls into batteries!" thing is bullshit; this is all about fabrication of thin, flexible, and odd-shaped cells. Think thinner mobiles, tablets, and laptops - not walls that'll gout fire when you hammer a nail into them.
posted by Pinback at 9:00 PM on June 29, 2012 [4 favorites]

Guess who would hate the increased impacts of Lithium mining. People who first really loved the idea of lithium battery paint, cause coal and gas are evil.
posted by kenaldo at 9:43 PM on June 29, 2012

How does this new lithium ion paint measure up in terms of flavour and mouthfeel?
posted by Sys Rq at 9:07 AM on June 30, 2012 [1 favorite]

NYC has an incredible density of cabs - wouldn't economic incentives to transition that fleet into electric/-hybrid/CNG/hydrogen make a ton of sense not only in reducing the carbon footprint of NYC much less improving the quality of life by increasing air quality?

Such a program did exist, don't know if it still does. Cabs outfitted for CNG got free fuel. The problem was that the fuel tanks took up the entire trunk and reduced the passenger area as well. The gas had to be picked up at just a few locations, so the logistics were not that good. They were not the preferred cabs for a ride from the airport with no trunk, and the cab could get stranded on any long ride.
posted by StickyCarpet at 7:39 PM on June 30, 2012

So after we spent decades painting lead on our walls and are still dealing with remediation, we are now going to start painting lithium on them? Maybe we should look to cadmium, too? I'd like to see some extensive studies on the environmental effects of the paint, its potential to be biodegraded, and the environmental impacts of its breakdown products before this is at all considered. Why not just put it in a container that can be easily recycled at the end of life?
posted by nTeleKy at 9:17 AM on July 2, 2012

Notice, the original article authors points out that painting everything with lithium isn't a practical approach for widespread application of this tech. They suggest it would be trivial to achieve the same result with safer materials. But obviously we'd have to be just as stupid if we rushed full on into this tech and started painting everything around us with toxic chemicals as we would be if we kept leaning on fossil fuels in the face of rapidly accelerating environmental problems like AGW and ocean acidification.
posted by saulgoodman at 1:43 PM on July 2, 2012

ACTION NEWS 12 SPECIAL REPORT:Are your walls giving you cancer? Details coming up next! But first, can you really trust your dog? The answer might shock you!
posted by blue_beetle at 3:55 PM on July 2, 2012 [1 favorite]