The 10kWh version was just cancelled, it's been in the technology press in
the last few days.

On Wed, Mar 23, 2016 at 8:49 PM, Sterling Jacobson <[email protected]>
wrote:

> I think they have two versions of powerwall?
>
> One that floats as backup mostly, and another that is solar fed and drains
> many cycles?
>
> Would those be two diferent battery types in them then?
>
>
>
> *From:* Af [mailto:[email protected]] *On Behalf Of *Eric Kuhnke
> *Sent:* Wednesday, March 23, 2016 9:48 PM
> *To:* [email protected]
> *Subject:* Re: [AFMUG] Tesla 7kWh powerwall as UPS?
>
>
>
> The thing is...  Calculating lead acid batteries as 30 or 15 cents per kWh
> to purchase doesn't take into account lifecycle cost. If the lead acid
> batteries are only good for 800 to 1000 cycles, absolute maximum, and the
> competing battery option is twice as expensive but lasts for 4000 or 5000
> cycles, the more expensive option actually costs a great deal less.
>
> It remains to be seen whether the powerwall will really hold up to
> thousands of cycles.
>
>
>
> On Wed, Mar 23, 2016 at 8:45 PM, Chuck McCown <[email protected]> wrote:
>
> 7/5=1.4 hours at full load.
>
>
>
> Batts are about 30 cents per watt hour for AGM, half that for flooded
> cells.
>
> Inverters are about 25 cents per watt.
>
>
>
> 7kWh battery == $1125 –$2250
>
> 5 kW inverter == $1250
>
> Put it on your critical loads.   Charge the batts with a rectifier that is
> fed from commercial power.
>
> You can run the inverter all the time, or use a smaller charger and put in
> a transfer switch.
>
> Transfer switches/contactors are not very expensive.  One single relay
> will do the job.
>
>
>
> *From:* Eric Kuhnke <[email protected]>
>
> *Sent:* Wednesday, March 23, 2016 7:45 PM
>
> *To:* [email protected]
>
> *Subject:* [AFMUG] Tesla 7kWh powerwall as UPS?
>
>
>
> $3000 is not so bad for something that can deliver up to 5kW for multiple
> hours...
>
>
> http://arstechnica.com/business/2015/09/tesla-powerwall-home-installations-are-starting-for-pilot-customers/
>
> I am interested to see the results of integrating two of these in parallel
> with an off grid solar array. At first glance it appears a great deal less
> expensive than buying a dozen 12V 200Ah lead acid AGM batteries to make a
> string. And should last a lot longer in 60% cycle depth daily cyclic use.
>
>
>
> Interesting they've cancelled the 10kWh model ($3500) which had a much
> shorter lifespan, the 7kW model is rated at 5000 cycles.
>
>
>

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