<div dir="ltr"><div class="gmail_default" style="font-family:times new roman,serif;font-size:large">Regarding 3 Power Walls PWs, more solar modules, and inverters. I hope this is helpful, I am always going to first principles. You did not mention what the customer expectations are. I see three common possibilities, 1) For backup power, in which case you need generation control, such as the AC Diversion control that Magnum solar used to make, or the frequency shift of the master PW shutting down the inverters. I have no idea how the PWs synchronize. Depending upon the model and age of the inverters they will back down until they shut off by frequency shift. From full power to shutoff is about 0.6 Hz. If the inverters do not have frequency shift power correction the inverters will shut down. Then stay down for 5 min until time to restart. 2) TOU or TOD (time of day energy pricing) with and without full net metering. The grid is connected the solar inverter can export when the battery is full. When the solar is insufficient the gateway programming directs the PWs to carry enough of the load to prevent power import. excessive charges. If you have two different pricing a study by Egauge or similar should be done to full fill the highest cost energy needs. This study should reveal the lowest price period and the amount of off-peak energy to buy. If you have data from the SMA or Egauge as to the past records you can modify your program using the probability of sun. 3) No export, this is similar to backup power except the grid provides synchronization and the inverters must have non-frequency power limitation. This is very tricky. . not sufficient power is </div><div class="gmail_default" style="font-family:times new roman,serif;font-size:large"> </div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Sat, Apr 17, 2021 at 2:26 AM Jason Szumlanski <<a href="mailto:jason@floridasolardesigngroup.com">jason@floridasolardesigngroup.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="auto">I think the limit is now stated as 7.6kw if memory serves me right.<div dir="auto"><br></div><div dir="auto">Jason</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Apr 16, 2021, 12:11 PM Matt Partymiller <<a href="mailto:matt@sesre.com" target="_blank">matt@sesre.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div lang="EN-US" style="overflow-wrap: break-word;">
<div>
<p class="MsoNormal">They used to advocate 7.9kW AC/DC per Powerwall. That number may have gone down recently. Coupling an inverter on the line side of the backup gateway will resolve your issue of meeting homeowner demand. Tesla will want you to add a CT
to that inverter to ensure it does not mess up their monitoring system, though that may already be incorrectly configured and not monitoring the whole home if the system is backup only.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Matt<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Matt Partymiller<u></u><u></u></p>
<p class="MsoNormal">General Manager<u></u><u></u></p>
<p class="MsoNormal">Solar Energy Solutions, LLC<u></u><u></u></p>
<p class="MsoNormal"><span style="font-family:"Merriweather Regular"">Lexington | Louisville | Bloomington | Cincinnati | Evansville | Indianapolis<u></u><u></u></span></p>
<p class="MsoNormal" style="vertical-align:baseline"><span style="font-family:"Merriweather Regular";color:black">859-312-7456 (Office)<u></u><u></u></span></p>
<p class="MsoNormal" style="vertical-align:baseline"><span style="font-family:"Merriweather Regular";color:black">877-312-7456 (General)<br>
<a href="mailto:matt@sesre.com" rel="noreferrer" target="_blank">matt@sesre.com</a><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-family:"Merriweather Regular""> <u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-family:"Merriweather Regular"">Check out our amazing new website and social media updates: <a href="http://www.sesre.com/" rel="noreferrer" target="_blank">www.sesre.com</a><u></u><u></u></span></p>
<p class="MsoNormal"><a href="http://www.sesre.com/" rel="noreferrer" target="_blank"><span style="font-family:"Merriweather Regular";text-decoration:none"><img border="0" width="45" height="45" style="width: 0.4687in; height: 0.4687in;" id="gmail-m_-7550801393344852797m_5440115797467579935Picture_x0020_1"></span></a><span style="font-family:"Merriweather Regular"">
</span><a href="https://www.facebook.com/SolarEnergySolutionsLLC" rel="noreferrer" target="_blank"><span style="font-family:"Merriweather Regular";text-decoration:none"><img border="0" width="48" height="48" style="width: 0.5in; height: 0.5in;" id="gmail-m_-7550801393344852797m_5440115797467579935Picture_x0020_2"></span></a><span style="font-family:"Merriweather Regular""> </span><a href="https://www.instagram.com/solarenergysols" rel="noreferrer" target="_blank"><span style="font-family:"Merriweather Regular";text-decoration:none"><img border="0" width="49" height="48" style="width: 0.5104in; height: 0.5in;" id="gmail-m_-7550801393344852797m_5440115797467579935Picture_x0020_3"></span></a><span style="font-family:"Merriweather Regular""> </span><a href="https://twitter.com/SolarEnergySols" rel="noreferrer" target="_blank"><span style="font-family:"Merriweather Regular";text-decoration:none"><img border="0" width="48" height="48" style="width: 0.5in; height: 0.5in;" id="gmail-m_-7550801393344852797m_5440115797467579935Picture_x0020_4"></span></a><span style="font-family:"Merriweather Regular""> </span><a href="https://www.linkedin.com/company/sesre" rel="noreferrer" target="_blank"><span style="font-family:"Merriweather Regular";text-decoration:none"><img border="0" width="48" height="48" style="width: 0.5in; height: 0.5in;" id="gmail-m_-7550801393344852797m_5440115797467579935Picture_x0020_5"></span></a><span style="font-family:"Merriweather Regular""><u></u><u></u></span></p>
<p class="MsoNormal"><u></u> <u></u></p>
<div style="border-right:none;border-bottom:none;border-left:none;border-top:1pt solid rgb(225,225,225);padding:3pt 0in 0in">
<p class="MsoNormal"><b>From:</b> RE-wrenches <<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org" rel="noreferrer" target="_blank">re-wrenches-bounces@lists.re-wrenches.org</a>>
<b>On Behalf Of </b>Kirk Herander, VSE<br>
<b>Sent:</b> Friday, April 16, 2021 11:13 AM<br>
<b>To:</b> <a href="mailto:re-wrenches@lists.re-wrenches.org" rel="noreferrer" target="_blank">re-wrenches@lists.re-wrenches.org</a><br>
<b>Subject:</b> [RE-wrenches] Powerwall 2 AC PV regulation<u></u><u></u></p>
</div>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black">Hello all,<u></u><u></u></span></p>
<div>
<p class="MsoNormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black">I am adding more PV to an orphaned Powerwall 2 AC system (which is all new to me), -3- PW's stacked to total about 40kwh of usable storage. it presently has about
13kw of PV, though -2- SMA inverters, feeding into it through a common subpanel between the PW gateway and the main panel. I'm wondering if there is a limit to the amount of PV the powerwall can regulate/backoff (or use for battery charging) during a utility
outage. What is the max PW charge rate? I need to add about 10 kw of PV to produce the owners goal of 100% coverage of electrical demand. <u></u><u></u></span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black">If necessary for safety, i assume the extra pv inverter can be routed to the main panel, and then won't participate in battery charging if the grid goes down. Am
I correct? Thanks. The PW manuals are of little use here.<u></u><u></u></span></p>
<div>
<p class="MsoNormal"><span style="font-size:12pt;font-family:Arial,sans-serif;color:black"><u></u> <u></u></span></p>
</div>
<div>
<p class="MsoNormal"><b><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Kirk Herander / <a href="mailto:kirkh@vermont.solar" title="Send an email to kirkh@vermont.solar" rel="noreferrer" target="_blank">kirkh@vermont.solar</a></span></b><span style="font-size:12pt;font-family:Arial,sans-serif;color:black"><u></u><u></u></span></p>
<p class="MsoNormal"><b><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Owner|Principal, VT Solar, LLC</span></b><span style="font-size:12pt;font-family:Arial,sans-serif;color:black"><u></u><u></u></span></p>
<p class="MsoNormal"><b><i><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">Celebrating our 30<sup>th</sup> Anniversary 1991-2021!!</span></i></b><span style="font-size:12pt;font-family:Arial,sans-serif;color:black"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black"><a href="https://nam02.safelinks.protection.outlook.com/?url=www.vermontsolarnow.com&data=02%7C01%7C%7C9f0330d75a244870112408d685311841%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636842843233477645&sdata=0NjyuKeQbEK6245SNnk8X4XnP9Q%2B%2BqtvcALkdDghvk4%3D&reserved=0" title="Click to open in a new window or tab
https://nam02.safelinks.protection.outlook.com/?url=www.vermontsolarnow.com&data=02%7C01%7C%7C9f0330d75a244870112408d685311841%7C84df9e7fe9f640afb..." rel="noreferrer" target="_blank"><b>www.vermont.solar</b></a></span><span style="font-size:12pt;font-family:Arial,sans-serif;color:black"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">dba Vermont Solar Engineering</span><span style="font-size:12pt;font-family:Arial,sans-serif;color:black"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10pt;font-family:Arial,sans-serif;color:black">802.863.1202</span><span style="font-size:12pt;font-family:Arial,sans-serif;color:black"><u></u><u></u></span></p>
</div>
</div>
</div>
</div>
_______________________________________________<br>
List sponsored by Redwood Alliance<br>
<br>
List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org" rel="noreferrer" target="_blank">RE-wrenches@lists.re-wrenches.org</a><br>
<br>
Change listserver email address & settings:<br>
<a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org" rel="noreferrer noreferrer" target="_blank">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br>
<br>
There are two list archives for searching. When one doesn't work, try the other:<br>
<a href="https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/" rel="noreferrer noreferrer" target="_blank">https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/</a><br>
<a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org" rel="noreferrer noreferrer" target="_blank">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a><br>
<br>
List rules & etiquette:<br>
<a href="http://www.re-wrenches.org/etiquette.htm" rel="noreferrer noreferrer" target="_blank">http://www.re-wrenches.org/etiquette.htm</a><br>
<br>
Check out or update participant bios:<br>
<a href="http://www.members.re-wrenches.org" rel="noreferrer noreferrer" target="_blank">http://www.members.re-wrenches.org</a><br>
<br>
</blockquote></div>
_______________________________________________<br>
List sponsored by Redwood Alliance<br>
<br>
List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org" target="_blank">RE-wrenches@lists.re-wrenches.org</a><br>
<br>
Change listserver email address & settings:<br>
<a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org" rel="noreferrer" target="_blank">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br>
<br>
There are two list archives for searching. When one doesn't work, try the other:<br>
<a href="https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/" rel="noreferrer" target="_blank">https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/</a><br>
<a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org" rel="noreferrer" target="_blank">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a><br>
<br>
List rules & etiquette:<br>
<a href="http://www.re-wrenches.org/etiquette.htm" rel="noreferrer" target="_blank">http://www.re-wrenches.org/etiquette.htm</a><br>
<br>
Check out or update participant bios:<br>
<a href="http://www.members.re-wrenches.org" rel="noreferrer" target="_blank">http://www.members.re-wrenches.org</a><br>
<br>
</blockquote></div>