<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Since the Powerwall is AC coupled, how will it know if the power source is a PV solar array or a generator if either feed the PV input? It seems simple AC switching is all that would be needed. I like to think outside the box but I\u2019m not familiar with Powerwall.<div class=""><div class=""><div class=""><div style="color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br style="orphans: 2; widows: 2;" class=""><span style="orphans: 2; widows: 2;" class="">Larry Crutcher</span><br style="orphans: 2; widows: 2;" class=""><span style="orphans: 2; widows: 2;" class="">Starlight Solar Power Systems</span><br style="orphans: 2; widows: 2;" class=""><br class=""></div></div></div><br class="Apple-interchange-newline">
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<div><br class=""><div class="">On Jul 20, 2020, at 9:53 AM, Jason Szumlanski <<a href="mailto:jason@floridasolardesigngroup.com" class="">jason@floridasolardesigngroup.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class=""><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"></div><div dir="ltr" class=""><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">The Powerwall 2 is now supported by Tesla in an off-grid configuration from what I heard. It is AC coupled. It cannot interact with generators whatsoever. You can't charge the battery with a generator and you can't AC couple a generator to it. If you want a generator, you put a transfer switch on the load side of the gateway device. If the battery dies, the generator starts. The generator powers loads, but does not recharge the battery because it becomes isolated via the transfer switch. The big downside I see with that is there would be a loss of power to the loads until the generator fires up. I don't see a way around that.</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br class=""></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">I'm not a Tesla certified installer, but I have seen some of these batteries out in the wild and that's just the way it is - it's an integrated unit. I'd call it an "AC Battery," kind of like an AC PV Module. To answer another point in this thread, if the battery reaches its LBCO it can only recharge with PV in an off-grid scenario. It reserves battery capacity to turn on occasionally to see if there is PV input. At least that's how I understand it to work. I don't know what would happen if the battery actually reached 0%. Seems risky. I'm not sure how you would "jump start" it. Publicly available details seem scant on this, but there are a few system owners talking about it if you dig deep on the Interwebs.</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br class=""></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">It will be interesting to see what Enphase comes up with. There are generator inputs on their Ensemble system, but no software support for this yet. The concept is very similar to Tesla in that there is a gateway device, essentially a transfer switch with battery controls inside. The Gateway acts as the AC point of coupling for everything to tie in together. </div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br class=""></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">I'm not sure why you couldn't use a generator to charge the Powerwall battery the same way you would charge with the grid. However, you would need a way to disable PV AC coupling when the generator is running. I can see how Enphase would be able to do this pretty easily. But Tesla is clear in that they do not allow a generator to interact with the Powerwall in any way.</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br class=""></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">Jason Szumlanski</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br class=""></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br class=""></div></div><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Sun, Jul 19, 2020 at 11:43 AM Hilton Dier III <<a href="mailto:hiltondier@gmail.com" class="">hiltondier@gmail.com</a>> wrote:<br class=""></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div class=""><p class=""><font face="Times New Roman, Times, serif" class="">Greetings, Wrenches,</font></p><p class=""><font face="Times New Roman, Times, serif" class="">I have an off-grid
client who has been reading the buzz about the Tesla Powerwall
2.0. I have been reading the data sheets and manual for it and
it appears to be AC coupled only. There was talk of a DC input
version, but apparently that fell by the wayside. I try to be
agnostic about technology, and I'd be willing to subcontract a
Tesla-approved installer if, in fact, this was the best
solution.</font></p><p class=""><font face="Times New Roman, Times, serif" class="">Does anybody have
experience using the Powerwall 2.0 in an off grid PV system? Is
it AC coupled only? Can it take generator power without barfing?
What is the lead time on these?<br class="">
</font></p><p class=""><font face="Times New Roman, Times, serif" class="">Many Thanks,</font></p><p class=""><font face="Times New Roman, Times, serif" class="">Hilton</font><br class="">
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Hilton Dier III
Missisquoi River Hydro
Renewable Energy Design
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