Hoping someone could help...

[gjohn]

Not sure if this helps but I am in MA also, have a StorEdge, a LG Chem battery which I use only for backup, and a subpanel for critical loads fed when the grid goes down by the battery.

@Willow1 - your experience in this case is immensely helpful. Thank you very much for making the effort to send those pictures too. I do recognize the inbuilt transfer switch for battery kick-on purposes. Looking at your wiring it looks like it may be possible that my electrician did not wire the way yours is, which may be putting me in this predicament ( but not yet sure). There is a small possibility that you might also have the same issue i have (see #3 below) ? Could you please help me figure out a few things:
1. which of the meter is the total solar measurement -i assume the grey NOT the black? and is that meter installed before the connections go to solar edge? I assume it is after.
2. on your StoreEdge picture, which line is the critical load and which one is the main panel load?
3. On a monthly basis does the reading from your TOTAL meter approximately equals what is reported by Solaredge? If not, could you please quote some numbers for one or two months, if possible?
4. is your crtical load panel put on a seperate fuze box that is only powered by Solaredge? ie there is only one incoming connection to that panel, and that is from Solaredge.
thank you very much.

[Ampster]

Not sure if this helps but I am in MA also, have a StorEdge, a LG Chem battery which I use only for backup, and a subpanel for critical loads fed when the grid goes down by the battery. The transfer switch is standard with the basic StorEdge unit and SE inverter. There are two Eversource installed meters. One for netmetering, and a separate one measuring total output that is used to calculate MA SMART credits. Here's a link to some photos which show the configuration (there is also a combiner box before the total output meter for some panels with microinverters separate from the Storedge/SE which you can ignore): https://1drv.ms/a/s!AurfEsR2BLA4geVLqD6qLmCZeEEYPw

Yes that helps. Perhaps that is what the OP means when he says he gets credits. You are probably talking about SREC credits and apparently your utility or whomever you sell the SRECs to (presumably Eversource) installs their own meters, one for production and one for net metering. I think the OP needs to get another meter installed or determine if the revenue grade meter in the StorEdge will suffice. The operative answer most likely will come from his power company not from this board.

[willow1]

Not sure if this helps but I am in MA also, have a StorEdge, a LG Chem battery which I use only for backup, and a subpanel for critical loads fed when the grid goes down by the battery. The transfer switch is standard with the basic StorEdge unit and SE inverter. There are two Eversource installed meters. One for netmetering, and a separate one measuring total output that is used to calculate MA SMART credits. Here's a link to some photos which show the configuration (there is also a combiner box before the total output meter for some panels with microinverters separate from the Storedge/SE which you can ignore): https://1drv.ms/a/s!AurfEsR2BLA4geVLqD6qLmCZeEEYPw

[Ampster]

yeah - ...... TOTAL solar power is what is sent to meter not net. obviously, that can be done in different ways and the meter needs to see 4Kw coming in and we are good. we also dont have peak-power differentials like in California (we are in MA). I do understand the physics (simple kirchoff's law in this case) thanks for trying to help and your ideas.

First off power is not sent, it flows to the loads. For solar power generated behind the meter the grid acts like a load. Physics determines that any solar generated will flow to the nearest load then to the grid which is what happens.The meter will only see the Net because the load is behind the same meter that the solar is behind. That load is closer than the load that the grid presents.

Forget the transfer switch for the moment. Also, I think Kirchoffs law is confusing the issue. Do you understand why the meter only sees the net? You would have to take the load somewhere else, for example behind a separate meter, and then all your production will be seen by your main meter.

The fundamental question is not really about how to set up a transfer switch, instead is is, how l get your utility meter to measure production without subtracting load? Is that not the issue? You as much said it when you said, "the meter needs to see 4Kw coming in and we are good."

If one can not do it with a simple circuit behind the meter, a transfer switch will not make it happen. I have no need to convince you if you do not want to see it that way. My comments are intended to be informative to the thousands of lurkers that may gain something from this conversation. I hope someone else chimes in with a point of view that clarifies it better than I have been able.

[gjohn]

yeah - you are not understanding the rate structure, no point in going there in detail as that is not the question at hand. TOTAL solar power is what is sent to meter not net. obviously, that can be done in different ways and the meter needs to see 4Kw coming in and we are good. we also dont have peak-power differentials like in California (we are in MA). I do understand the physics (simple kirchoff's law in this case) thanks for trying to help and your ideas.

Anyone out here who can answer the ATS and solaredge question? - that would be very helpful - calling on all experts. All ideas and perspectives welcome. thanks.

[Ampster]

thanks. good point - but the catch is that we live, we get credits also for the TOTAL production of the solar as seen by the utility-issued meter for the next 10 years due to solar promotions, in additions to savings you mentioned above.

The critical phrase is, "...as seen by the utility-issued meter....".

in your example, the meter sees only 3kW and therofore i get only credit for 3KW-h instead of 4KW-h.

Yes that is the physics. You can't change that.

The other credit is ofcourse the calculation you did above. Another reason to have the storEdge to not send power to CriticalLoad directly is due to the SENSE monitor, which currently gets confused as the electric flow reverses in the critical-line (when solar over produces) and cannot calculate the total usage correctly. By forcing the current to go via the main panel, sense will see the total used by the house.

The simple solution is to move the Sense CT. I have mine on the main service entrance. It sees power going in both directions and comes up with a consumption and generation number based on what the Solar sensor is reading. The Sense is only programmed to calculate the consumption by using the two pairs of CTs in that fashion,.

I think you may have some expectations that are not consistent with how this stuff actually works. I also may not understand your rate structure and the mechanism of how you get credit for production. The SolarEdge Inverters I believe are revenue grade so the issue is what kind of meter will your power company accept for that production measurement. If they will accept the SolarEdge production numbers then you would not have to install a separate meter to just measure production. Otherwise there is no work around that I can see. A transfer switch will not effect what your single meter sees.

[gjohn]

Mathematically and electrically it doesn't make much difference if you power your critical loads from the grid or from solar. Lets assume your inverter is putting out 4kW and your critical loads are 1kW. Your meter will see the difference of 3kW being the Net power generated. If you ran the system for an hour you would get credit for 3kWhrs of electricity. I assume you get credited at the same rate that you pay.

thanks. good point - but the catch is that we live, we get credits also for the TOTAL production of the solar as seen by the utility-issued meter for the next 10 years due to solar promotions, in additions to savings you mentioned above. in your example, the meter sees only 3kW and therofore i get only credit for 3KW-h instead of 4KW-h. The other credit is ofcourse the calculation you did above. Another reason to have the storEdge to not send power to CriticalLoad directly is due to the SENSE monitor, which currently gets confused as the electric flow reverses in the critical-line (when solar over produces) and cannot calculate the total usage correctly. By forcing the current to go via the main panel, sense will see the total used by the house.

[Ampster]

Hi Amster: there are indeed multiple breakers......... The time-based system doesnt make much sense for me over what i proposed because in my drawing the critical load will always be powered by the utility until there is a power outage, in which case the battery kicks in via StoreEdge. I want to minimize the discharge of the battery as well and use it only when there is a power outage (to prolong battery life).

Mathematically and electrically it doesn't make much difference if you power your critical loads from the grid or from solar. Lets assume your inverter is putting out 4kW and your critical loads are 1kW. Your meter will see the difference of 3kW being the Net power generated. If you ran the system for an hour you would get credit for 3kWhrs of electricity. I assume you get credited at the same rate that you pay.

So my question is do you see a problem in putting an ATS as shown in the diagram? it would have been great if Storedge had a profile that doesnt send PV power (partially) to critical loads when the grid is on, but we havent found a setting in storedge to make that happen (including from the link you sent - unless i am misunderstanding). I dont mind loosing a tiny amount of PV power to an ATS switch.
thanks
Joanne

Maybe not a problem but you are not going to change the result by putting in a transfer switch, StorEdge does NOT decide where to send the power because power will flow to the loads behind the meter before any excess is sent to the grid. Physics is what makes that happen. The only way you could see the difference is to install a separate meter. Then the question becomes will your power company let you offset generation on one meter with the load from the other meter. Then mathematically the result will be the same, but electrically the power will be equalized at the nearest transformer or the common connection to those meters.

I know you don't want to use your battery except when needed for backup. However depending on your TOU rates you might be able to improve the return on your investment by programming your inverter to use the battery to ride through the peak rate. Then you would charge the battery at super off peak rates. Two issues will determine if that is economical. One, is the rate differential between peak and the lowest off peak rate. Two, the warranty on your battery. What TOU rates are you signed up for and what type of battery do you have? Does the battery have a warranty, which assumes being used by a StoreEdge Inverter?

[gjohn]

Hi Amster: there are indeed multiple breakers that are not shown for simplicity, so it is not a line-side tap. There is a breaker to protect the grid workers (between Solaredge and meter) as well as between panels and storedge for system shutdown. All of this is installed by a professional electrician but he doesn't know much about the Solaredge system (again, you are correct the StorEdge inverter). The time-based system doesnt make much sense for me over what i proposed because in my drawing the critical load will always be powered by the utility until there is a power outage, in which case the battery kicks in via StoreEdge. I want to minimize the discharge of the battery as well and use it only when there is a power outage (to prolong battery life). So my question is do you see a problem in putting an ATS as shown in the diagram? it would have been great if Storedge had a profile that doesnt send PV power (partially) to critical loads when the grid is on, but we havent found a setting in storedge to make that happen (including from the link you sent - unless i am misunderstanding). I dont mind loosing a tiny amount of PV power to an ATS switch.
thanks
Joanne

[Ampster]

I don't understand your diagram. You show the SolarEdge being wired directly to the meter. Does it go through a breaker on the main service panel or is it a line side tap?
If I understand your goal, you want to sell all the power generated by your panels to the grid. The easiest way to do that is to find out if there is an internal setting that will do that. Otherwise you would need to define when the transfer would operate. It could be time based or measurement of some output. If you really want to take advantage of TOU rates you may want to run the critical loads on batteries during the entire peak rate period. It would be simple in concept to find a transfer switch that could be triggered by a timer.
A quick Google search found the following:

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.solaredge.com/sites/default/files/storedge_charge_discharge_profile_programming.pdf&ved=2ahUKEwiDrYTavNvmAhXUJzQIHdaXCGEQFjAAegQIARAC&usg=AOvVaw1dNSCRnIQhaxdlfXfLSAuK

I am assuming you have a StorEdge inverter.

[gjohn]

I have a similar problem i hope someone can answer (for some wired reason, i cant start a new thread). I have Solaredge installed for solar panels and connected to backup power battery (LGChem) with no other back up source like generator. The battery is managed by solaredge for backup. The critical (aka backup) load is currently connected directly to solaredge which results in some of the solar produced to go to power the critical load when solar is producing. As i do not want this to happen (our utility gives credit for what is put back to grid), i came up with the idea of installing an auto-transfer switch to switch to backup power from solaredge-connected battery. Are there any solaredge experts who can confirm i can connect an autotransfer switch on the critical-load panel feed coming from solaredge? I am worried about something that may not be obvious to a non-expert like me (e.g any wait time needed for solaredge to do a power surge to ATS). I have included a detailed diagram below to (see circled area). If it wont work, please tell me why.
Also does anyone have any advice on a good lasting but not too expensive (< $400) ATS or similar gadget (30 Amp or higher) that can work with a battery-based backup setup ?
Thank You for your help.
Joanne

[gwm1471]

Thank you all for your input. I bought a 11k generator (used) and replaced my dying one...so that is up and running. Solar...my buddy had a separate panel (some house and workshop circuits) for just the solar/battery setup that is why he had a charge controller so I will install it as he had it set up. At least I am all set for the winter... Thank you all again!

[J.P.M.]

Not dumb at all. But it does show some solar ignorance. Once you get educated with respect to the potential and limitations of alternate energy and PV in particular, you'll have a better perspective from which to make more informed decisions.

Get the generator fixed/replaced for emergencies. Grid tie the PV if you want but get more informed before you attempt it. If you do, you'll probably still need the genny. Stand alone PV for emergencies isn't worth the hassle/cost, at least not at this time.

[SunEagle]

20x250PVs that a big experiment

Using those panels on a grid tie system would make sense. But trying to build an automatic emergency power system using batteries instead of a generator is an experiment that will cost you more then replacing that generator.

[Paul Land]

If you want a science experiment than proceed with you experiments but if you need reliable backup power buy a new generator or fix the one you have. The cost and complexity to do what you want will exceed the cost for a generator.

20x250PVs that a big experiment