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Panasonic and Tesla Sign Agreement for the Gigafactory

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Re: Panasonic and Tesla Sign Agreement for the Gigafactory

#51
post #36
post #4

Earlier quoted context omitted.

I don't see why they wouldn't, they already sell their powertrains to other companies. It would probably depend on how much extra capacity they have. The Tesla vehicles are in high demand and only going to be in more demand when they start rolling out the Tesla 3 (which is really the 4th Tesla isn't it, I guess they're referring to it being the 3rd generation with the Model S and X being the same generation).

Elon gave a funny explanation for the new name: he would have wanted a Model E to compose S E X, but the name was already taken. So he chose 3 to at least have S 3 X.

I don't know why this is being downvoted. Elon Musk himself confirmed that S, E, and X was supposed to make fun of how sex is used in marketing to sell.

Re: Panasonic and Tesla Sign Agreement for the Gigafactory

#52

Earlier quoted context omitted.

This doesn't explain why LiPoly batteries are cuboids.

Indeed it does not, this is about Tesla's and Panasonics 'gigafactory' which will make Lithium-Ion batteries in a cylindrical form factor. Lithium Polymer batteries (or LiPo for short) are a special case of Lithium-Ion batteries. They are sold in a 'pouch' format (and they are not the first to use a format like that, for instance, in the polaroid cartridges there used to be a battery in a similar form factor (polapul…

Also, and this is entirely speculation and I'd love to hear a battery engineer confirm this, but: if you're packaging together cylindrical batteries, it inherently gives you more air channels between the batteries to promote cooling. When you're talking tens of kilowatts, both in discharge and charge rates, the percentage that ends up as waste heat suddenly becomes a whole lot of heat. You probably wouldn't want a maximally stuffed cavity with these packs turning into a single, massive chunk of thermal mass.

EDIT: looks like I was firsted somewhere below, doh!

Re: Panasonic and Tesla Sign Agreement for the Gigafactory

#53
post #50

Earlier quoted context omitted.

http://www.autotrader.co.uk/search/used/cars/postcode/l331ze...

I need to do more research on the Leaf but yeah that is a close contender. The Zoe is a problem. I love Renault cars, my Clio was my favourite thing in the world, but the Zoe has DRM in the battery which you have to rent from Renault for a fee based on your mileage, which as far as I could tell, worked out to more than I would pay in petrol. I believe, although it may have been FUD, that if you go over the mileage yo…

It seems like it would be FUD, as the capability to remotely disable the car (and dealing with the liability from doing that in a inconvenient or even dangerous place) seems rather expensive, when you might as well just check the milage when it's serviced (not servicing your new or new-ish car at an authorized dealership is a great way of slashing its resale value).

Re: Panasonic and Tesla Sign Agreement for the Gigafactory

#54
post #28

This just shows me that Tesla is able to execute. The Gigafactory, opening up patents, rapidly growing charger network, and the eventual $35k Gen III tells me they have tons of potential in the future. Tesla is thinking big. They want everyone in the world to eventually have a electric car. I think they will own a significant share of premium market after they release the Gen III. However, they will be cars that peop…

Okay, but when does the factory first come online? The projections are for by 2020, so where do any possible cost savings for the III come from? Unless we can expect it to slip a few more years like the X did. I am hoping for a 200 mile range mid size, but I doubt Tesla will be first. I am also expecting range extender vehicles to have much more popularity initially because to be honest, I don't have time for 30 minu…

> Okay, but when does the factory first come online? The projections are for by 2020, so where do any possible cost savings for the III come from? Unless we can expect it to slip a few more years like the X did.

Tesla has already broken ground in several states for the Gigafactory (with plans to discard the sites they choose not to move forward with). I think 18-24 months is a reasonable timeline for them to be online.

Re: Panasonic and Tesla Sign Agreement for the Gigafactory

#55
post #33

Has there been any analysis on the amount of joule energy pumped out of all of the current gas stations on a daily basis? I'm worried the current electric grid is woefully insufficient for a world full of electric cars. I know their are plenty of electric lines out there running at greater than 100% of their rated capacity already.

Napkin math supports your concerns.

- The US used 134.51 billion gallons of gas in 2013.[1] - There are ~33 kWh/gal in gasoline [2]

134.51e9 gal x 33 kWh / gal = 4.44e12 kWh (4.44 trillion kWh / year)

- The US used a total of 3.856 trillion kWh of electricity in 2011 [3]

Ignoring improved efficiency and excluding other factors, converting all gasoline usage to electric would more than double US electricity consumption.

Under reasonable assumptions, PV solar generates about 0.75 kWh/m^2 per day. [4]

4.44 trillion kWh/year / 0.75 kWh/m^2 per day x 365 days/year / 1e6 m^2 per km^2 = 16,219 km^2

Which means you could generate all of the required electricity with about 16,200 km^2 of solar panels - which is just about exactly the total land area of Hawaii [5], or 405 million average home PV systems.

It's doable, but it will be non-trivial.

[1] http://www.eia.gov/tools/faqs/faq.cfm?id=23&t=10 [2] http://en.m.wikipedia.org/wiki/Gasoline_gallon_equivalent [3] http://www.eia.gov/energyexplained/index.cfm?page=electricit... [4] http://physics.ucsd.edu/do-the-math/2011/09/dont-be-a-pv-eff... [5] http://en.m.wikipedia.org/wiki/List_of_U.S._states_and_terri...

Re: Panasonic and Tesla Sign Agreement for the Gigafactory

#56
post #33

Has there been any analysis on the amount of joule energy pumped out of all of the current gas stations on a daily basis? I'm worried the current electric grid is woefully insufficient for a world full of electric cars. I know their are plenty of electric lines out there running at greater than 100% of their rated capacity already.

My assumption is that most of the charging for electric vehicles (aside from stopping at a supercharger) will go on at night which is off peak for our grid now. At least for the short term future. I don't know that solar will help in that case. The adoption of electric vehicles seems to be slow enough that it should give us time to identify the problems and attempt to come up with solutions. That rate could significantly increase if the model 3 delivers on it's promises. It probably still take major investments in our electrical infrastructure to support a majority of vehicles becoming electric.

Re: Panasonic and Tesla Sign Agreement for the Gigafactory

#57
post #36

Earlier quoted context omitted.

Elon gave a funny explanation for the new name: he would have wanted a Model E to compose S E X, but the name was already taken. So he chose 3 to at least have S 3 X.

I don't know why this is being downvoted. Elon Musk himself confirmed that S, E, and X was supposed to make fun of how sex is used in marketing to sell.

[deleted]

Re: Panasonic and Tesla Sign Agreement for the Gigafactory

#58
post #33

Has there been any analysis on the amount of joule energy pumped out of all of the current gas stations on a daily basis? I'm worried the current electric grid is woefully insufficient for a world full of electric cars. I know their are plenty of electric lines out there running at greater than 100% of their rated capacity already.

Napkin math supports your concerns. - The US used 134.51 billion gallons of gas in 2013.[1] - There are ~33 kWh/gal in gasoline [2] 134.51e9 gal x 33 kWh / gal = 4.44e12 kWh (4.44 trillion kWh / year) - The US used a total of 3.856 trillion kWh of electricity in 2011 [3] Ignoring improved efficiency and excluding other factors, converting all gasoline usage to electric would more than double US electricity consumptio…

If I read this right this is assuming that all current gasoline usage is converted into electrical usage. It's not like that would happen over night though, or possibly ever. Also, can PV help at night when a majority of charging should occur?

Re: Panasonic and Tesla Sign Agreement for the Gigafactory

#59
post #47

Earlier quoted context omitted.

It's an efficiency matter. The cylinder gives good electrode surface relative to the amount of matter contained. For a cube that ratio would be much worse, for a sphere it would be optimal, but spheres are harder to manufacture and connect to, as well as harder to stack in arrays. So we take a medium between the sphere and the cube and end up with a sweet spot in the cylindrical shape.

Why not stack flat plates like a car battery?

Because it would be more expensive and the space gain would be very small.

Battery geometry is mostly dictated by physics and economics, even though a flat plate battery would be denser the gains in density would be off-set by the increase in cost and in the end the wasted space doubles as a cooling channel so you might end up having to separate your flat plates by periodic air channels anyway.

The reason why flat plates are better in some applications (for instance, for starter batteries in cars) is because those batteries are optimized for very high current during very short bursts of time. 300 Amps @ 12V is 3.6KW out of a very compact little box. The power generated from that little package is extremely impressive (if you pull the distributor cap on your car (if you have an old car) you can actually move the car for a bit on the starter engine in first gear or reverse!) but because of the short duration the power absorbed by the battery is relatively small (current is absorbed by the internal resistance of the battery during charge and discharge leading to a warming up of the battery).

But it does not last for very long so heat removal is not usually a problem, and the charge currents are reasonably low, so again no big problem in removing the heat (low current, longer time).

With electric vehicles the situation is reversed, the discharge time is relatively long (hours) but the charge times are getting ever shorter which means packs have to be actively cooled to avoid overheating, and the easiest way to do that is to flow air through gaps in the cells.

Re: Panasonic and Tesla Sign Agreement for the Gigafactory

#60
post #52

Earlier quoted context omitted.

Indeed it does not, this is about Tesla's and Panasonics 'gigafactory' which will make Lithium-Ion batteries in a cylindrical form factor. Lithium Polymer batteries (or LiPo for short) are a special case of Lithium-Ion batteries. They are sold in a 'pouch' format (and they are not the first to use a format like that, for instance, in the polaroid cartridges there used to be a battery in a similar form factor (polapul…

Also, and this is entirely speculation and I'd love to hear a battery engineer confirm this, but: if you're packaging together cylindrical batteries, it inherently gives you more air channels between the batteries to promote cooling. When you're talking tens of kilowatts, both in discharge and charge rates, the percentage that ends up as waste heat suddenly becomes a whole lot of heat. You probably wouldn't want a ma…

But you're 100% on point there. That's a side benefit from having those cylindrical cells.
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