On average. You use $220/month. Your RMP blended average rate is most likely 12 cents per kWh. So 220/.12=1833 kWh/month /30=60 kWh per day.
From: Sterling Jacobson Sent: Wednesday, March 23, 2016 9:48 PM To: [email protected] Subject: Re: [AFMUG] Tesla 7kWh powerwall as UPS? What are you doing that uses 50 kWh/day? Is that to charge your car? That can’t be normal. I think my power bill is around $220 a month, what is my average kWh/day based on that? From: Af [mailto:[email protected]] On Behalf Of Chuck McCown Sent: Wednesday, March 23, 2016 9:39 PM To: [email protected] Subject: Re: [AFMUG] Tesla 7kWh powerwall as UPS? 2.2 kWh Batts of that size would cost $700 1.8 kW inverter. That would cost $450 They plan to sell it for $1700. And they are not saying that this can pull the one single load for one hour. It will store about 25 cents worth of power. Tesla is 7 kWh. I use about 50 kWh/day. Tesla would run my house for 3 hours on average, but since the power consumption is not continuous, when I am actually using lots of juice it would probably last for less than an hour. From: Sterling Jacobson Sent: Wednesday, March 23, 2016 8:22 PM To: [email protected] Subject: Re: [AFMUG] Tesla 7kWh powerwall as UPS? 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:[email protected]] On Behalf Of Eric Kuhnke Sent: Wednesday, March 23, 2016 7:54 PM To: [email protected] 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 <[email protected]> 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.
