Hard to tell. But the calculator has you pick the load you want to plug into it. And the only way you can save money is if you have time of day rates.
From: Sterling Jacobson Sent: Wednesday, March 23, 2016 9:53 PM To: af@afmug.com Subject: Re: [AFMUG] Tesla 7kWh powerwall as UPS? Oh, so maybe they used tricky marketing. For some reason it looked like you plugged the Orison into the wall and it magically powered everything around it from just that one plug. Are you saying it has outlets to plug other stuff in to? If so, then I guess I just bought myself a pretty looking UPS. Which I’m ok with I guess. If not, then how does it handle the load transfer, and what happens when the power goes and the load is too high? I guess it would just trip a breaker or something and power would be gone until the load is changed and breaker reset in the Orison. From: Af [mailto:af-boun...@afmug.com] On Behalf Of Chuck McCown Sent: Wednesday, March 23, 2016 9:39 PM To: af@afmug.com Subject: Re: [AFMUG] Tesla 7kWh powerwall as UPS? If you pull up the calculator, it is nothing but a UPS for your selected loads. From: Eric Kuhnke Sent: Wednesday, March 23, 2016 8:56 PM To: af@afmug.com Subject: Re: [AFMUG] Tesla 7kWh powerwall as UPS? There's a lot of marketing fluff there and not much technical info. I'm not sure how it can safely or legally feed power "backwards" into the same 120V 15A circuit it's plugged into, particularly during an outage if a house does not have a grid disconnect permanently installed. More likely the design is that it charges itself from an input 15A circuit, and has a separate set of power outlets/sockets which you can connect loads to. On Wed, Mar 23, 2016 at 7:22 PM, Sterling Jacobson <sterl...@avative.net> wrote: I purchased one of these to play with: https://www.kickstarter.com/projects/ericclifton/orison-rethink-the-power-of-energy I’m not sure exactly how they work their magic, but you should just be able to plug it into the same power strip and it will charge, and supply power in case of an outage? All on a common 15amp 110v plug. We’ll see how it actually goes in August when I get mine. I also pre-ordered a powerwall like a year ago and haven’t heard much back from Tesla. I would probably use the powerwall in a solar setup combo if I move. It’s tempting to get a few and string them together for my office, but it would take some creative engineering to wire it in correctly on a transfer switch I think. From: Af [mailto:af-boun...@afmug.com] On Behalf Of Eric Kuhnke Sent: Wednesday, March 23, 2016 7:54 PM To: af@afmug.com Subject: Re: [AFMUG] Tesla 7kWh powerwall as UPS? There's not a lot of technical information available about them, don't they have an integrated sinewave DC-to-AC inverter? I could be wrong but I believe they output AC. Assuming a typical installation for their target market, residential, do they require purchase of a separate DC-to-AC inverter? They're rated at 3.3kW load (AC) to power a house. On Wed, Mar 23, 2016 at 6:48 PM, Bill Prince <part15...@gmail.com> wrote: Only hassle is that they are 450 volts (or in that neighborhood). Big challenge finding DC-DC converters for that, or maybe go back to battery-inverter-DC power supply design. bp <part15sbs{at}gmail{dot}com> On 3/23/2016 6:45 PM, Eric Kuhnke wrote: $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.
