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Tesla Energy

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Re: Tesla Energy

#581

Post by kragen »

Dylan16807 wrote: post #580
kragen wrote: post #578

Earlier quoted context omitted.

Are you really saying that a metal bucket full of saltpeter (tree stump remover) is “exotic” compared to a giant electrical battery based on lithium, a metal which doesn’t exist in nature, violently explodes on contact with water, and needs a solid-state electronic charge controller to keep the battery from exploding when you charge it? Why would you say something like that?

By itself it's not exotic. Using it in molten state to cook things is exotic, yes. Lithium clearly exists in nature. Elemental lithium might not, but they don't make the batteries from that either. Molten salt also explodes on contact with water. A charge controller is unnecessary. It's just a cheap way to improve efficiency. The bucket of salt would have a similar controller. Also since price isn't a part of the equ…

You have some good points. I didn't realize that lithium-ion batteries didn't actually contain metallic lithium! I thought they did, just like nonrechargeable lithium batteries, but you're right. Thank you!

However, I don't think it's true that the charge controller is just a cheap way to improve efficiency; it's actually necessary to keep the battery from exploding like a firebomb when you try to charge it.

The bucket of molten salt has a much higher energy density for cooking purposes, although you're right that this only becomes an overwhelming factor if you consider joules per dollar instead of joules per kilogram. Lead-acid batteries are 0.17 MJ/kg; the particular molten saltpeter mix commonly used for energy storage is 0.16 MJ/kg just from the melting, plus another 0.3 or 0.4 MJ/kg from melting, depending on the temperature range. The practicality difference is that saltpeter costs US$1/kg, while lead-acid batteries cost about US$6/kg.

Re: Tesla Energy

#582

Post by Dylan16807 »

kragen wrote: post #581
Dylan16807 wrote: post #580

Earlier quoted context omitted.

By itself it's not exotic. Using it in molten state to cook things is exotic, yes. Lithium clearly exists in nature. Elemental lithium might not, but they don't make the batteries from that either. Molten salt also explodes on contact with water. A charge controller is unnecessary. It's just a cheap way to improve efficiency. The bucket of salt would have a similar controller. Also since price isn't a part of the equ…

You have some good points. I didn't realize that lithium-ion batteries didn't actually contain metallic lithium! I thought they did, just like nonrechargeable lithium batteries, but you're right. Thank you! However, I don't think it's true that the charge controller is just a cheap way to improve efficiency; it's actually necessary to keep the battery from exploding like a firebomb when you try to charge it. The buck…

>However, I don't think it's true that the charge controller is just a cheap way to improve efficiency; it's actually necessary to keep the battery from exploding like a firebomb when you try to charge it.

You only need to worry about it when you're riding near the edge of what the batteries can handle. If your solar array outputs 4 volts and needs a minimum of 6 hours to mostly-charge the batteries, and your batteries are in a nice cool basement, I'm pretty sure you can just hook them all together. It wouldn't be ideal but I don't think you'd have any real fire hazard.

Re: Tesla Energy

#583

Post by justatdotin »

aquark wrote: post #309
ZoFreX wrote: post #261

This is a three-pronged stroke of genius: 1) Immediate benefits to just about anyone. If you have your own solar panels, you need this (or something like it). Even if you don't, you can benefit by drawing more power during cheaper off-peak times. 2) If lots of people get in on this, we'll have the storage capacity we need on the grid to be more dependent on renewable energy. Lack of storage capacity is one of the big…

re 1: part of the benefit of solar locally is that the rate you get for pushing power back into the grid is way in excess of what you have to pay to pull it out. Whilst storing it for your own use later makes sense in theory, it doesn't work with the current economics

lucky you. Here (in one of the sunniest cities of the world) you can only earn parity - if you're lucky. The power company are disallowing new grid-feed connections in some suburbs because their aged infrastructure can't handle too much 'unconventional' input. (!!)

Re: Tesla Energy

#584

Post by mauricemir »

iamthepieman wrote: post #299
mauricemir wrote: post #223

Earlier quoted context omitted.

Yes talk to telco Engineers from the power side of the biz and they will have war stories about accidents and close misses with the Central Offices (Exchanges) DC power. High Voltage/Amperage DC is quiet different to AC power and i suspect that building/wiring codes are going to need to be updated if this local storage takes off.

dropped a wrench across the terminals on the deep cycle backup batteries inside a telco switching center. Had to disconnect the whole bank of batteries to fix it because the wrench welded itself to the terminals. it wasn't a tack weld either.

The one I remember is decorators placing a paint tin across the bus bars - which explosively painted the walls

Re: Tesla Energy

#585

Post by kragen »

Dylan16807 wrote: post #582
kragen wrote: post #581

Earlier quoted context omitted.

You have some good points. I didn't realize that lithium-ion batteries didn't actually contain metallic lithium! I thought they did, just like nonrechargeable lithium batteries, but you're right. Thank you! However, I don't think it's true that the charge controller is just a cheap way to improve efficiency; it's actually necessary to keep the battery from exploding like a firebomb when you try to charge it. The buck…

>However, I don't think it's true that the charge controller is just a cheap way to improve efficiency; it's actually necessary to keep the battery from exploding like a firebomb when you try to charge it. You only need to worry about it when you're riding near the edge of what the batteries can handle. If your solar array outputs 4 volts and needs a minimum of 6 hours to mostly-charge the batteries, and your batteri…

Well, you clearly know more about Li-ion batteries than I do, so you’re more likely to be right about that.

Re: Tesla Energy

#586

Post by criley2 »

psychometry wrote: post #367
criley2 wrote: post #335

Earlier quoted context omitted.

>" but it's not like Elon Musk has saved the world just yet." "I choose to rent, I choose to have no property rights over the building I live in, I choose to be legally incapable of installing solar panels and batteries on a structure I don't own: Elon Musk has failed me" Come on now. You made your choice to not be a part of the greater community and culture of property owners. These options, they're available to own…

Oh, give me a break. Asking your landlord to switch ISPs is not the same as instantly acquiring 100 grand to buy yourself a Tesla automobile. Nor is it the same as instantly having the financial and personal freedom to say "I'm going to go buy some property!" Have you ever considered that some people can't buy certain things because they don't have the means to do so? (Save me the tirade of libertarian talking points…

"I'm not blaming Elon for anything and I don't really have any interest in owning property at the moment. I'm simply pointing out that his company isn't really changing the lives of most people.

Please, sir, it's ME who needs to be given a break.

* I'm not a libertarian as you have insultingly labeled me, I'm a social democrat

* Just because you cannot afford a $3500 battery doesn't mean anything except you cannot afford a $3500 battery

* Had you watched even 10 minutes of Elon's presentation, you'd understand that your utility could install a large scale version of these for your benefit. It doesn't have to be a personal installation, a 'smarter' grid means you can send your solar during the day to a central storage run by a utility or government, and then spend that credit when you draw from grid at night.

* Considering that utilities can do this, that means socially speaking, a government could invest in these. In fact, you'll find California providing deep incentives for exactly this kind of work.

Your "100k on a Tesla" remark, when in reality we're discussing $3500 batteries and similarly priced solar setups, goes a long way towards showing that you have an IRRATIONAL reaction here, not a rational once. You clearly have not investigated even the basics of this, and are using hyperbole to make an emotional statement. $100k would power several homes independently of the grid, or power a multi-family structure like an apartment building.

You could ask your landlord to install a $3500 battery, that's a conversation you could have with your landlord.

It's one you choose not to have, and even though you choose that, you still blame Elon.

This world will change without you. Your attitude is no different that that "one guy" we all know who has a clam-shell dumbphone and is good with it. The world changed around him, although that one guy we know is still bemoaning that Steve Jobs did nothing for him.

For all we know, apartment complexes will install 50kwh setups with solar panels on their facility as a way to attract people: "NO POWER BILLS! POWER INCLUDED IN RENT! NO BROWNOUTS! NO BLACKOUTS!" It'd be a powerfully interesting marketing tactic. Just because you don't own a house doesn't mean Elon's ideas can't change the world.

Re: Tesla Energy

#587

Post by create123 »

mikeash wrote: post #573
alkonaut wrote: post #569

Earlier quoted context omitted.

When the used batteries start piling up, it's best for tesla if this system is already in place. Entirely possible that this will be new and subsidized batteries initially. They will need to find a use for the old car batteries.

Could be, but they're jumping the gun a lot if that's the main idea. Tesla sales didn't really ramp up until 2014, and the batteries will probably last at least 10 years in the cars themselves. In any case, they wouldn't need to subsidize these batteries. $350/kWh is a pretty decent price, and consistent with estimates of what they cost in Tesla's cars.

The large packs are priced at $250/kWh which I think is the real news. That means their cost is very likely under $200. Don't think the other car manuf are close to that.

Re: Tesla Energy

#588

Post by create123 »

parasubvert wrote: post #553
rhino369 wrote: post #500

Earlier quoted context omitted.

Doesn't Telsa already sell a product like that?

The home charger cable is capable of 240V/80A (20 kWh) connections. Superchargers are around 363V/225A (90 kWh) but supposedly capable of 120 kWh. http://www.autoblog.com/2013/02/01/hands-on-with-the-tesla-s... So you're looking at 3 hours at home vs 45 minutes at a supercharger for a full charge. With the 10 kWh wall charger you might be able to cut 45 min off a home charge.

Not possible. The specs on their site say 2.0kW continuous and 3.3 peak power per power wall.

Re: Tesla Energy

#589

Post by Yaggo »

fredkbloggs wrote: post #338
Yaggo wrote: post #83

Earlier quoted context omitted.

That's crazy cheap. The closest competitor which comes into my mind is probably SMA Sunny Boy Smart inverter with lithium battery, costing more than double while offering only 2 kWh of energy (but includes a solar inverter).

It's not crazy cheap at all. The incumbent technology here is flooded lead-acid, a proven solution used everywhere from telco COs to forklifts to off-grid cabins for over a century. Industrial FLA batteries (the top grade, longest-lasting, etc.) retail for somewhere around $250 per kWh, and typically have warranties ranging from 7 to 10 years. We don't know exactly what the differences are between Tesla's two offerin…

I meant "crazy cheap" as lithium-based product, i.e. compared to other lithium chemistry storages. Sure, lead-acid technology still offers better capacity/price ratio, but lithium chemistry has many advantages especially when used as domestic energy buffer for sun: longer lifespan (more cycles) in daily use, more peak power, wall mountable / lighter, etc.

Re: Tesla Energy

#590

Post by Angostura »

jarvist wrote: post #343
Angostura wrote: post #314

Earlier quoted context omitted.

I think I'd want to see an environment impact assessment of manufacturing the batteries.

OK; here's a well cited study from 2010 on electric cars: http://pubs.acs.org/doi/abs/10.1021/es903729a "The share of the total environmental impact of E-mobility caused by the battery (measured in Ecoindicator 99 points) is 15%. The impact caused by the extraction of lithium for the components of the Li-ion battery is less than 2.3% (Ecoindicator 99 points). The major contributor to the environmental burden caused b…

Thank you for that, much appreciated.
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