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Re: Tesla Powerwall

Posted: Fri May 01, 2015 3:46 pm
by JimSouCal
palmermd wrote:
Zythryn wrote:
JimSouCal wrote:Did you see happen to see the video of the Tesla car fire where the packs lost integrity and burned..? The batteries exploded and burned till the energy was spent in an impressive display like a firework shipment catching fire. Garages are the most common starting point of residential fires... Probably due to gasoline autos...

My point is I don't think there is a household fire suppression technology that would put a dent on the batteries if they became involved in a house fire...

Cell phone and laptop have a much smaller capacity and energy potential. Just sayin...
Luckily I rarely drive my garage over three ball hitches at highway speeds ;-)

And the prescribed solution for a battery fire on a Tesla pack is to drown it in water....pretty sure that technology is available in most homes.

http://www.teslamotors.com/blog/model-s-fire" onclick="window.open(this.href);return false;
Ok, I misunderstood about the water working, so a sprinkler head would work. I am renovating and considering putting sprinklers in the garage. By the way, the Tesla fire I speak of was a stolen one here in Los Angeles, and it was more impressive than the one you link out too. Yes, I know gas cars burn with a fury too!

Re: Tesla Powerwall

Posted: Fri May 01, 2015 3:46 pm
by sparky
EVDRIVER wrote:
TimLee wrote:$350 per kWh is the real news.
Beats the few competitors out there by quite a bit.
Does pretty clearly show that Nissan's $250 per kWh replacement heat resistant pack with trade-in is at least somewhat below production cost.

:?:
I'm not sure it shows anything more than Tesla charges more. It can also show Nissan has lower costs and better economies of scale. Comparing the cost of two different battery types, configs and from two different makers does not draw any concrete conclusions. Let's see what Apple decides to use in their 200 mile autonomous car...
One difference: Nissan's $250/kWh includes them taking your battery pack in trade and giving you another non-BMS pack in return. So, I don't see much lower costs for Nissan.

Re: Tesla Powerwall

Posted: Fri May 01, 2015 4:03 pm
by sparky
Musk's presentation. It's available multiple places but this one seems to skip the commercials.
I got the invite to Tesla's Hawthorne Design Center for the 8pm event. Took forever for him to get onstage and talk for about 20 mins. Food was pretty good and plenty of free drinks. Nice to see a lot more people in their 20's-30's in the audience than the usual Tesla crowd (yes, I resemble that remark).
He's not the most polished but I always have this idea that he's working out 2 or 3 other things (landing rocket on hovercraft, hyperloop car pods...). in his head while he's doing a dog & pony. Mom-Musk and his kids were there... sweet.

Not just Tesla owners milling about. I spoke to some "power" people. LEED-type architecture firms and industry consultants. They have just started working with Tesla on a mid-scale project and seemed pretty impressed so far. They think the utility industry is about to be blind-sided again (as with PV popularity). I have no idea if they're right but I've been hearing about electricity storage being the next big thing for about 5 years now.
Maybe.
Dunno when or if I'll buy one of these gadgets.

Re: Tesla Powerwall

Posted: Fri May 01, 2015 4:38 pm
by evnow
The rated power of 2 kW is almost useless for any home.

I'd been researching backup generators - minimum that would work in our house is about 7/8 kW.

Re: Tesla Powerwall

Posted: Fri May 01, 2015 5:27 pm
by AndyH
2k1Toaster wrote:
JimSouCal wrote:In theory, I am very fond of this idea. I'd be inclined to install the unit away from the house in a utility room made out of cinder block, in the same manner I might store propane tanks or gasoline, vented, but not in my attached garage... Paranoid or circumspect...?
Only if you charge all your cell phones and laptops in that outdoor shed too.

Make sure it is insulated so the battery doesn't get too cold...
I'm with Jim. I charge all my LiCo either on the cement back porch with 3' of clearance all around or in a fireproof bag.

Paranoid or circumspect? Doesn't matter. I like the 'alive, no matter what fails' part, personally. :)

Re: Tesla Powerwall

Posted: Fri May 01, 2015 5:37 pm
by AndyH
sparky wrote:Musk's presentation. It's available multiple places but this one seems to skip the commercials.
I got the invite to Tesla's Hawthorne Design Center for the 8pm event. Took forever for him to get onstage and talk for about 20 mins. Food was pretty good and plenty of free drinks. Nice to see a lot more people in their 20's-30's in the audience than the usual Tesla crowd (yes, I resemble that remark).
He's not the most polished but I always have this idea that he's working out 2 or 3 other things (landing rocket on hovercraft, hyperloop car pods...). in his head while he's doing a dog & pony. Mom-Musk and his kids were there... sweet.

Not just Tesla owners milling about. I spoke to some "power" people. LEED-type architecture firms and industry consultants. They have just started working with Tesla on a mid-scale project and seemed pretty impressed so far. They think the utility industry is about to be blind-sided again (as with PV popularity). I have no idea if they're right but I've been hearing about electricity storage being the next big thing for about 5 years now.
Maybe.
Dunno when or if I'll buy one of these gadgets.
Thanks for the link and report!

I think the utility industry's in the midst of a couple of rapid-fire blind-siding events. ;)

http://climatecrocks.com/2015/04/16/why ... l-be-huge/
http://rameznaam.com/2015/04/14/energy- ... and-cheap/
A 2014 report by leading investment bank UBS noted, “Our view is that the ‘we have done it like this for a century’ value chain in developed electricity markets will be turned upside down within the next 10–20 years, driven by solar and batteries.” UBS surmises that less-expensive batteries, solar PV, and electric vehicles will empower customers to make their own energy decisions, and effectively make traditional power plants irrelevant by 2025.
http://blog.rmi.org/blog_2015_04_14_fin ... are_coming


Re: Tesla Powerwall [Cost Advantage?]

Posted: Fri May 01, 2015 5:45 pm
by sakumar
Is there a cost advantage to installing the Powerwall? I don't see it.

I already have solar panels and and am on a Time Of Use (Northern California PG&E E-9) plan with my electric utility.

I get that I would have power if there is an outage, but that is not a compelling enough reason for me.

I can't see how there is a cost advantage here. Currently I "sell" excess generation to PG&E and later use it. However, the utility remembers that I sold them power at a higher rate and then sells it back to me at a lower rate. I would lose this advantage with the PowerWall. I generate a kilowatt-hour during peak times that would be worth (say) $0.50 and later use it when off-peak at say $0.30. So in that scenario I'm $0.20 ahead. But if, instead, I store the generated power in the PowerWall and use it later, I lose the $0.20 advantage. What am I missing here?

Re: Tesla Powerwall

Posted: Fri May 01, 2015 5:45 pm
by AndyH
UPDATE: SolarCity tells Bloomberg that a 9-year-lease for the 10kWh Powerwall costs $5,000, including installation, maintenance, inverter, and control system. Buying the system upfront costs $7,140.
http://www.theverge.com/2015/5/1/852530 ... nouncement

Re: Tesla Powerwall [Cost Advantage?]

Posted: Fri May 01, 2015 10:26 pm
by JimSouCal
sakumar wrote:Is there a cost advantage to installing the Powerwall? I don't see it.

I already have solar panels and and am on a Time Of Use (Northern California PG&E E-9) plan with my electric utility.

I get that I would have power if there is an outage, but that is not a compelling enough reason for me.

I can't see how there is a cost advantage here. Currently I "sell" excess generation to PG&E and later use it. However, the utility remembers that I sold them power at a higher rate and then sells it back to me at a lower rate. I would lose this advantage with the PowerWall. I generate a kilowatt-hour during peak times that would be worth (say) $0.50 and later use it when off-peak at say $0.30. So in that scenario I'm $0.20 ahead. But if, instead, I store the generated power in the PowerWall and use it later, I lose the $0.20 advantage. What am I missing here?
For the times when power is out (rare but happens), it may very well be worth for some IF having a powewall unit means a microinverter AC array can be left producing leaving one to load manage. Also, the sell back arrangement varies by utility so some may have less pricing delta to take advantage of...?

Re: Tesla Powerwall [Cost Advantage?]

Posted: Sat May 02, 2015 3:21 am
by RegGuheert
sakumar wrote:Is there a cost advantage to installing the Powerwall?
At a more basic level: What problem does Powerwall solve?

The only obvious one that I can see is it provides a way for Tesla to sell more automotive battery packs so that he can try to fill his Gigafactory.

But I don't think a battery pack (originally) engineered for an automobile makes a good wall hanging. I have to wonder if these are already in use today for remote supercharger stations. That application has high value for Tesla and makes a decent amount of sense, but I don't see the same value for hom use.

Even ignoring the hazards mentioned, this thing will simply waste power if hung outdoors on an outside wall in a hot climate.

So, what is the main application?
- Backup generator replacement?
- Off-grid PV?
- Grid-tied PV with backup?
- TOU shifting?

Of all of those, only TOU shifting seems to provide a way for the unit to try to pay for itself. But at a 2kW power rating, you would need a bunch of these for most homes with central air conditioning. But it needs an inverter to have any use. I agree that Solar City will be involved if there are PV applications here.

Frankly, I think Enphase is more on track with their AC Battery. It's small enough and cheap enough for people to experiment with it while still being scalable to large applications.