Tesla announces "Powerwall" batteries

[Sunking]

Yeah.

So 30% less DoD lets it withstand 7x more charge cycles? Really? That seems a bit high.

Are you just waking up to reality? the 7 Kw and 10 Kw are the exact same battery. The 10 year warranty is toothless and paying lip service.

[russ]

My posts are mild, and I'm just trying to be factual, or in your own words, "brutally honest".

Pardon? Delusional maybe but brutally honest or factual? Hardly!

[SunEagle]

Why whoops? What it means is that Tesla and the solarcity inverter maker haven't figure out how to allow the end user to reliably operate both grid and battery simultaneously.

From pv magazine:

U.S. inverter specialist Fronius will collaborate with Tesla from the fourth quarter of the year, bundling its Symo Hybrid inverter with the Tesla Powerwall home battery to customers in Germany initially, before rolling out the package to the rest of Europe and Australia.

Now go look at Fronius Symo Hybrid inverter functionality.

Unfortunately what Tesla is doing is providing false hope to people who believe the battery will provide them enough to go through a grid outage but the amount of power a single or even 3 of those 10kWh systems will not allow you to run a lot of your appliances and AC for long or at all. Sure the Tesla may cost less than the other battery systems but it is still not cost effective at this time and price.

I still don't understand why people in Germany or Europe would decided to spend a lot of money on battery systems without thinking about getting any return on their investment or at least minimizing the cost.

[Sunking]

Sure the Tesla may cost less than the other battery systems

That is not accurate, Tesla may want you to believe that, but not factual. Even top of the line FLA and AGM cost less and proven to last. Secondly as learned yesterday the $3000 and $3500 price Tesla is completely bogus, as Tesla and Solar City now say you can buy the battery outright for $7000 and no discount for quantity. That jacks up the price to $1000 - Kwh or 5 to 6 times higher than top of the line FLA.

No one was more disappointed than I was. But the way the PR was worded and illusive answers smelled of a Rat. After following Tesla and Musk for 9 years I have learned he is just a slick used car salesman who has made a fortune from Tax Payers money.

[Willy T]

No one was more disappointed than I was. .

This is good for a laugh. Had you planned on installing one in your golf cart ??

[Amy@altE]

That is not accurate, Tesla may want you to believe that, but not factual. Even top of the line FLA and AGM cost less and proven to last. Secondly as learned yesterday the $3000 and $3500 price Tesla is completely bogus, as Tesla and Solar City now say you can buy the battery outright for $7000 and no discount for quantity. That jacks up the price to $1000 - Kwh or 5 to 6 times higher than top of the line FLA.
.

The $7000 includes the inverter, obviously you'd need one regardless of which type of battery, and installation and maintenance. Figure at least $2k for the inverter, probably closer to $3k, and I can see where the $7k comes from. But I did the math, the price per watt for just the 7kWh battery is about the same as Aquion's stack, and 2X as much as the Trojan Industrial line and some AGM batteries.

[bberry]

I still don't understand why people in Germany or Europe would decided to spend a lot of money on battery systems without thinking about getting any return on their investment or at least minimizing the cost.

It's a big world with a lot of different needs and wants. The "home appliance battery" is now half the cost it was before Tesla's announcement. That change increases demand. Do you have a good understanding of worldwide demand for a home battery with the characteristics of the Powerwall? I don't.

The home battery announcement isn't the important part anyway. It's just the relatable aspect that can be used by journalists. What Tesla and competitors can deliver to commercial and utility users is what matters.

The business plans of new batteries are justified by the potential size of the utility and commercial markets. That should be exciting, because it potentially improves residential solar. Especially off grid. Who really wants to use a FLA battery system that would be high tech yet familiar on a WWII uboat?

[bberry]

That is not accurate, Tesla may want you to believe that, but not factual. Even top of the line FLA and AGM cost less and proven to last. Secondly as learned yesterday the $3000 and $3500 price Tesla is completely bogus, as Tesla and Solar City now say you can buy the battery outright for $7000 and no discount for quantity. That jacks up the price to $1000 - Kwh or 5 to 6 times higher than top of the line FLA.
........

First, all rational people will go with the lease. Second, why would solarcity discount? They will not be able to get enough Powerwalls to meet demand for several years. Powerwalls won't be the only choice in several years.

Complaining that the price isn't $3500 is like complaining that it costs extra money to retrofit your car with a newly announced, inexpensive engine.

[DanKegel]

I did the math, the price per watt for just the 7kWh battery is about the same as Aquion's stack, and 2X as much as the Trojan Industrial line and some AGM batteries.

http://www.trojanbattery.com/pdf/Sma...rn_Handout.pdf does make their industrial FLA line sound pretty good (speaking as a non-battery-expert with just a smattering of EE background).

Which AGM batteries are you talking about?

But the litany of potential pitfalls at http://www.survivalunlimited.com/bat...ryblunders.htm makes me think that any consumer battery solution is going to need to include remote monitoring and periodic service by the installer as part of the deal. Do you agree, and what does this add to cost of real-world systems you've seen?

[DanKegel]

Who really wants to use a FLA battery system that would be high tech yet familiar on a WWII uboat?

Don't laugh at lead-acid just yet. There's some life left in that technology, it's way down its cost curve, and it's got a killer track record.

[Amy@altE]

Which AGM batteries are you talking about?

I randomly picked the Outback EnergyCell 200RE. 12V 178Ah C/20, designed for daily use with solar. 2136Wh for $425. 4 of them for 48V = 8.54kWh and costs $1700. Granted, without Tesla's life cycle data or DoD, you can't compare lifetime costs, but purely on price per Wh, AGM wins.

[Amy@altE]

For flooded, SunKing's favorite series: Trojan's IND9-6V, 464Ah @ 6V for $834. 4 in series for 24V (just to keep things in the same range) = 11.1 kWh for $3,336.

[DanKegel]

Sunking's advice was to always check the warranty, so let's see:

http://www.outbackpower.com/outback-products/energy-storage/item/energycell-re

says the warranty is 2 years, and does not cover "routine or daily discharge of more than 40% of capacity".

http://www.trojanbattery.com/pdf/TRJ...edWarranty.pdf says the warranty
is 3 years outright and 8 years prorated, and covers 50% DoD.

http://www.teslamotors.com/powerwall just says "10 years". Since they haven't claimed DoD yet, people are making guesses (I've seen 70%, 80%, and "it's really a 12 kWh battery", http://rameznaam.com/2015/04/30/tesl...-almost-there/).
For comparison, http://bosch-solar-storage.com/the-s...echnical-data/ says 5 years, 50% DoD for their lithium system.
If I had to make a wild guess, I'd assume their 7kWh battery is really a 12 kWh battery, warrantied to handle a daily discharge of 7kwh for 5 years, ramping down to some lower figure at 10 years.

If you include the known warranty terms from Trojan and Outback, and your own reasonable guess at Tesla's warranty terms, what are the resulting lifetime cost per kWh?

[Amy@altE]

I prefer comparing cycle counts. Outback at 5 hour rate (only one I see on their datasheet) says 5700 cycles at 20% DoD and 1800 at 50% DoD. That's 15 years down to 5 years. People shouldn't be designing their system for 50% daily discharge, if they are, they get what they pay for. So I'll even cut this in half for a 10 year life. I know certain royalty will strongly disagree with me. But even if the AGM has half the life of the PowerWall, at half the price, available now, and works with standard equipment, I'm still not sold on Tesla. Yes, technically the flooded may still the best cost over life of system, but most homeowners will not take care of their batteries, so it will not meet its potential lifespan. So for the right person, by all means, flooded, but for Joe Homeowner, AGM.

[SunEagle]

....... but for Joe Homeowner, AGM.

Joe Homeowner should use the Grid as their battery.

Maybe people like Tesla will come up with something that is very cost effective on a much larger scale used by the POCO at specific grid points to smooth out the variable voltage fluctuations and outages caused by RE. If that is perfected then Joe Homeowner shouldn't need to worry about having his own energy storage system but can still install some type of emergency power gen set that powers more than a few lights and fans.