Watch Elon Musk unveil Tesla's Powerwall, a $3K battery for your home to 'change the world'

The solar flares won’t fry a grid that’s prepared for that. The mechanism is saturating the transformer cores with induced DC current, and that’s easy-ish to defend against (switch off the transformer when it starts overheating (and possibly cause a cascade blackout), or run it at below 90% load to have reserve. Short-haul lines aren’t susceptible, long-haul ones will hopefully be replaced with HVDC in time.

I see the chance rather in “energy auctions”; smart grid, knowing the supply forecast for next seconds to hours, adjusting energy prices per minute. So the freezer knows that there is abundance of cheap power just now, and it can afford to store the energy now, and sink the excess wind power flowing in. Or the batteries can play the role of a market speculator, charging when the power is abundant and discharging back to the grid for a markup when there is a shortage. Similarly, said freezer knows it can go from say -18 to -14 'C safely if the energy is overpriced at the moment, or decide that instead of risking a $500 groceries load it will play it safe and buy the more expensive power to be sure instead of waiting. The consumer then can select appropriate strategy for the household or device.


As someone who spent days after Sandy listening to neighbors’ generators and fantasizing about blowing them all up, I’d love to see this tech take hold. It was like living on a helicopter landing pad. Musk is at least trying to push us forward and in the right direction, taking on big projects and acting on big ideas without any quick payoff. I like what I know about the guy.


That’s a different problem space, lol!

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I heard you like battery chargers, so I…

(I’ll show myself out now.)


Forcing everyone to live in cities is unrealistic and unnecessary. Rural communities can be sustainable, and the environmental effects of living outside a city can be mitigated with technology like this.

Many communities are always going to be rural and like it that way. To the extent that this makes it easier for them to be green, it’s a good thing.

Aside; did you know 40% of Native Americans don’t have access to electricity? Seems to me this is exactly the kind of thing that’s needed to serve that population. Or would you have them all move to the city?


I thought they were going to live in artisan bell-making communes.


Of course there are appropriate applications, and anyone who sat through Musk’s uninspired presentation knows about some of them. I’m talking about unintended consequences – I’m not talking about forced relocation of happy small-town Americans, a group that includes me, to cities. I’m talking about voluntary relocation of entitled, high income city people to very rural sites, far from shopping and services, which is already a problem. One of the few things that minimizes the sprawl is the cost of running power to their little slice of paradise.

Aren’t those motors supposed to be pretty much disposable? I had a friend in high school who was way into RC car racing and he burnt out a ton of motors, and the NiMH batteries weren’t the culprit either, because he bench-tested one of the motors with a DC power supply and the thing burnt out after just a few hours at 90% of it’s advertised output.

(I was thinking for charging cell phones and flashlights. Not violating the laws of thermodynamics.)

This is very confusing to me. Which is it? Does the world use 2000 GW, or 15000 GW?

Also, according to Wikipedia, the world’s energy consumption in 2008 was 143,851TWh
143,851TWh divided by (365.25*24) gives 16.41TW of power usage, which is several orders of magnitude larger than either of the figures quoted in the excerpt (and those two values differ by a factor of more than 8).

I have the feeling that someone doesn’t know unit conversions or the difference between energy and power.

Power consumption includes non-electric things like much transportation, heating etc.

Perhaps I am missing something, but 16.41 TW seems close enough to 15 000 GW.


You’re not missing anything. I was just hoist with my own petard here, overlooking the fact that 15000GW is 15TW.

“1 gram of powdered cocaine earns a 5 year sentence but 1000 whole milligrams of crack cocaine is 25 to life.”


Given how much cities suck, it makes sense that if you can afford it you get out of there.

Edit: And those who can will rationalize why it is good, those who cannot will rationalize why the ones who can and do are bad.

They are being run rather hard. Cooling must be apparently handled carefully. (Thought. Could the generator part be enclosed in hydrogen atmosphere?)

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Wouldn’t SF6 be much better than hydrogen for this purpose? Since it has really high heat capacity? Also, hydrogen is pretty reactive while Sulfur Hexaflouride is mostly inert and a very good electrical insulator.

Wouldn’t. It is a big and heavy molecule and has low thermal conductivity and high viscosity. Hydrogen is used industrially for cooling the large generators in “grown up” power plants. Same low viscosity trick is used for some Western Digital hard drives that are filled with helium.

The reactivity per se is not that much of a problem. It’s more about penetrating through many materials and leaking, and embrittling many alloys.

The electrical insulation is not that bad, just about 65% of air. Just run the generator at lower voltage (industry often uses about 6 kV) and transform it up afterwards. Use low viscosity good-cooling gas for the lower-voltage lots-of-movement part, use SF6 or other good dielectric gas for the high-voltage side switching equipment.
Here, enjoy the table I wrote down few years ago when just this question was bugging me.


The problem with electrolyzers it that it’s easy to make an incredibly efficient one, if you have an unlimited amount of platinum. The less platinum you use for your electrode, the less efficient it gets.

Actually, ruthenium is the best. Usually used on iridium support, can be on tantalum support as well.

Another common one is iridium oxide.

And there’s an intense research, for obvious reasons, of cheaper alternatives. Nickel/nickel oxide nanoscale heterostructures look promising:

Nanoheterostructures look quite promising as a catalyst family in general. Catalysis is one of the fields where nanotech will have a major impact.

What the hell? There are different communities to live in. Different people prefer different lifestyles. The same person may prefer different lifestyles in one lifetime.

What’s with all the hate and bigotry against city dwellers?


In my case it is not hate against any specific city dweller, but dislike towards too many people in too small area. Taken individually, any of them is okay by default. Taken together, too much of everything.

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No! There is only one way to live. Differing opinions are not allowed.