<div dir="ltr"><div dir="ltr"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">AC coupling the Enphase IQ8 microinverters with a generator and no batteries is a supported setup with their System Controller 2 or 3G. The "Sunlight Only Backup" system in this configuration starts the generator automatically during a grid outage, but generator power will only be used if the loads exceed the PV inverter combined output. This is intended to reduce fuel burn, presumably, and start up large loads. I'm not sure how they deal with large loads dropping off, but the IQ8 responsiveness to load changes is supposed to be lightning fast, so I assume they have that all figured out. There are sizing ratio limits.</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">We have never installed a system like this (without batteries), and I can't imagine a scenario where I think it would be worthwhile in a residential setting unless there is a consistently moderate to high load during daylight hours. I just don't think the reduction of fuel burn would be substantial enough to justify the expense and complexity of the System Controller. Standby generators often run near idle anyway around here except when air conditioners cycle on and off. With pool pumps being so efficient, and often left out of backup load panels anyway, there are not many consistent loads in a house in a grid-outage scenario that would benefit the homeowner by reducing fuel consumption substantially. Unfortunately, it's hard to find ideal fuel burn figures for many generators to do proper estimates.</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">So a question aside from "what happens" if you AC couple a generator with PV is whether it's even worth it.</div><div><div dir="ltr" class="gmail_signature"><div dir="ltr"><br>Jason Szumlanski<div><span style="color:rgb(51,51,51);font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px">Principal Solar Designer | Florida Solar Design Group</span><br style="color:rgb(51,51,51);font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px"><span style="color:rgb(51,51,51);font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px">NABCEP Certified Solar Professional (PVIP)</span><br style="color:rgb(51,51,51);font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px"><span style="color:rgb(51,51,51);font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px">Florida State Certified Solar Contractor CVC56956</span></div></div></div></div><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Dec 1, 2023 at 7:16 PM Jerry Shafer via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</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">Wrenches<div dir="auto">Without batteries uou do not want to do this, l have tested small generators to excite larger solar inverters to run constant loads but if the inverters out power the loads then the smoke comes out so not advisable </div><div dir="auto">But hey thats just a guy that has been in the business for many years.</div><div dir="auto">Fun times.</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Nov 30, 2023, 5:20 PM Jeremy Rodriguez via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org" target="_blank">re-wrenches@lists.re-wrenches.org</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">Has anyone experienced a grid tie inverter back feed a whole house backup generator after a utility outage? <br>
What can happen ?<br>
<br>
<br>
Jeremy Rodriguez <br>
Solar Installation / Design<br>
All Solar, Inc.<br>
1453 M St. <br>
Penrose Colorado 81240<br>
<br>
Sent by Jeremy's iPhone. Sorry for typos and shorthand. <br>
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