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EG4 18kpv best option for grid connection with 100 amp panel

pr3dat0r6sic6

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Southern, CA
Hello everyone long time lurker first time poster.

After about a year of reading and watching videos from will plus my own DIY experiment of setting up my pool's pump off grid. I finally decided to pull the trigger on a system for the whole house. I ordered a EG4 18kpv, 16 × Solarever 455W (in addition to the 8x 370w panels I laready have), and the new EG4-WallMount Indoor Battery.

I got the inverter and panel delivered last week and had my electrician friend come over who will be helping me install the system. We took a look at my existing panel and come up with a game plan. We are a little confused on what is the best option for me based on my home's current 100A panel. I attached pictures of my panel.

Based on the Decision Tree diagram I have a meter main with accessible cables from the meter to the 100a main breaker. So we would use the whole home backup with a supply side tap diagram.

Is this the best option? What is the forum's opinion on what I should do?
 

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Where will your electrician friend install the Solar breaker to put solar into the panel?

Based on every single spot being filled up and no place to put a solar breaker, I would go with a critical loads panel and leave A/some 30/40 amp breakers in the original panel, and move the others to the critical loads panel. This frees up more spots to add later.

100 amp service is like having a 24 kW inverter, to include surge power.

An 18 kW inverter won't provide 18 kW constant of power. I don't know your loads, it may be enough. Also, how will you deal with the guest / family factor who won't know limits like why can't I turn all four burners on the stove, run the double oven, and run the air conditioner like I did last year? IME, they tend to think if they do it once or when I'm not around, it'll be harmless.

Also, pay close attention to the surge rating of the inverter. I don't know your loads, you do. With surge, the 18 kW inverter won't handle the surge that your grid does now.

My Outback is a beast, but it has it's limits. My 4500 watt AC can surge to 26 kW to start it, and it starts 50 or 60 times a day. The Outback worked fine until the hotter part of the summer when there were multiple loads coming on, and the AC would not start or start noisily when the Outback ran it. This is a 16 year old air conditioner with a hard start already installed plus three extra capacitors I don't know what they do. An easy start could help, but this is a 16 year old air conditioner past its 10 year life that has shown signs its on its way out. Not sure I want to throw more money at this AC to get the Outback to run it, continue with the grid until the AC dies, or replace the AC.
 
Sorry I should of mentioned this. You may notice the one 30A breaker that is off that was going to a outlet in the garage for an electric clothes dryer. I ran gas lines for our gas clothes dryer so no plans to use this. We were going to pull that breaker and move the other ones up so we can place the back feed breaker at the bottom of the busbar.
 
If I understood correctly.
You will be installing the 18kpv in between the meter main and the house panel. (As a line side tap)
And the question is breaker and wire size?
They will remain the same as they currently are.

You currently have a 24kw (100a) panel feeder.
And you will be adding a 12kw inverter with the ability to pass through the 24kw (actually twice that) without issue.
 
Sorry I should of mentioned this. You may notice the one 30A breaker that is off that was going to a outlet in the garage for an electric clothes dryer. I ran gas lines for our gas clothes dryer so no plans to use this. We were going to pull that breaker and move the other ones up so we can place the back feed breaker at the bottom of the busbar.
You don't need a backfeed breaker with a line side tap.
 
You don't need a backfeed breaker with a line side tap.

Sorry I should of mentioned this. You may notice the one 30A breaker that is off that was going to a outlet in the garage for an electric clothes dryer. I ran gas lines for our gas clothes dryer so no plans to use this. We were going to pull that breaker and move the other ones up so we can place the back feed breaker at the bottom of the busbar.
I still like the idea of the critical loads panel.

Unless you're comfortable with the 18 kW inverter having the surge capabilities of your loads, I still think its a good idea to move some loads over. In testing in the winter, my AC powered up just fine with my inverter, but it was not until things got hot and the constant usage the surge limitations showed up.

There's some strategies I can't do because of my surge limitations, mainly running off battery at peak rates, or running off battery with the AC on.
 
Ok so were planning on using this diagram. My confusion is my main service breaker is on the busbar how are we supposed to place the manual transfer switch in the diagram between that and the panel.


1720474985874.png
 
I still like the idea of the critical loads panel.

Unless you're comfortable with the 18 kW inverter having the surge capabilities of your loads, I still think its a good idea to move some loads over. In testing in the winter, my AC powered up just fine with my inverter, but it was not until things got hot and the constant usage the surge limitations showed up.

There's some strategies I can't do because of my surge limitations, mainly running off battery at peak rates, or running off battery with the AC on.
1. The house panel is basically a critical loads panel.
2. It's not an 18kw inverter, it's a 12kw inverter.
 
Ok so were planning on using this diagram. My confusion is my main service breaker is on the busbar how are we supposed to place the manual transfer switch in the diagram between that and the panel.


View attachment 227321
Sorry, this is the first mention of the manual transfer switch.
Is there also a breaker in the meter main? (I assume there is)
Then the connection points can be moved on the diagram.
The supply side tap is after the meter main's breaker and your panels main breaker is in place of the panels main lugs.
All new connections are between your two existing breakers.
 
My meter main has accessible cables in the customer compartment going from the meter socket to the main breaker.

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How about putting polaris connectors on the lines going to the service breaker, and connecting those lines to the grid input of the inverter. The load output would then connect to the service breaker.
 
My meter main has accessible cables in the customer compartment going from the meter socket to the main breaker.
My mistake.
I thought that the original pictures were of two different panels.
I thought that the picture of the open panel was an interior sub panel.
What I suggested won't work in your situation.
Without rebuilding the entire service, your best option is to install a separate loads panel and move the circuits over to it. And place the 18kpv and manual transfer switch in between them.
 
How about putting polaris connectors on the lines going to the service breaker, and connecting those lines to the grid input of the inverter. The load output would then connect to the service breaker.
That does seem like a good idea but my main concern would be what if the inverter failed? We'd be without power until we can pull the meter socket and remove the inverter between the meter and the main breaker.
 
I left my outside panel, tapped it with a 100A breaker to an automatic transfer switch. A Pair of 18KPV's for 24KW/100A to the primary on the ATS. Common on the ATS to a shiny new 125A breaker panel...

ATS: https://www.amazon.com/Automatic-Transfer-Switch-Isolated-Generator/dp/B0BPQPCCJC/

Use the load lugs on the the EG4 to the new panel. Tap 100A breaker from the old panel to the grid lugs on the EG4. Configure and go.
 
That meter main buried in the wall, posses some real challenges.
1. I don't think (can't remember) that you can leave that enclosure with unprotected service conductors, and return from another source.
2. Buried in the wall, makes it very hard to access.
 
I'm thinking a critical loads subpanel might be the best move. We can move some of our heavier loads like our AC, pool pump, electric stove, electric cooktop to the subpanel so they can run of solar and the battery. The AC is a big one our SCE bill doubled from about $350/mo to $850 once summer hit. Once I start getting some ROI on this system I can set aside to do a main panel upgrade.
I'm looking for the route that will require the least additional investment to start saving us some money on our Edison bill.
 
I'm thinking a critical loads subpanel might be the best move. We can move some of our heavier loads like our AC, pool pump, electric stove, electric cooktop to the subpanel so they can run of solar and the battery. The AC is a big one our SCE bill doubled from about $350/mo to $850 once summer hit. Once I start getting some ROI on this system I can set aside to do a main panel upgrade.
I'm looking for the route that will require the least additional investment to start saving us some money on our Edison bill.
What is the goal?

You don’t need to move the loads to the subpanel to self consume. As long as you can get CT sensors around the correct part of the panel. You do need to know the loads for emergency grid down power, or if the CTs cannot be installed.

You rarely need to do a MSP upgrade for solar. I am backfeeding 20kW of solar into PG&E with a 40 year old 100A MSP. This is with a grandfathered MSP that can’t be upgraded cheaply due to various annoying PG&E rules.

Subpanels are cheap materials wise. It’s a labor question, and since no POCO power cut/restore (or pulling meter, which PG&E doesn’t want me doing) is needed you can do that slowly on your own clock
 
Based on the Decision Tree diagram
Can you paste the decision tree?

Before you go down the line side tap rabbit hole (and I'm not a fan of line side taps, you can avoid them with your panel by moving all the breakers out to a subpanel & using Sum of Breakers rule / aka Hawaiian tie in), please confirm with SDGE or SCE that they will let you.

This approach isn't in the 18kpv manual.
 
What is the goal?

You don’t need to move the loads to the subpanel to self consume. As long as you can get CT sensors around the correct part of the panel. You do need to know the loads for emergency grid down power, or if the CTs cannot be installed.

You rarely need to do a MSP upgrade for solar. I am backfeeding 20kW of solar into PG&E with a 40 year old 100A MSP. This is with a grandfathered MSP that can’t be upgraded cheaply due to various annoying PG&E rules.

Subpanels are cheap materials wise. It’s a labor question, and since no POCO power cut/restore (or pulling meter, which PG&E doesn’t want me doing) is needed you can do that slowly on your own clock
The main goal for me is lowering our bill. Living in the hot SoCal foothills 110 heat this weekend and a 15month old sun and wife who stay at home our AC is the biggest driver of the energy consumption. If I just got that load off SCE and 100% powered by solar and my battery I would start working my way towards full ROI.

Can you paste the decision tree?

Before you go down the line side tap rabbit hole (and I'm not a fan of line side taps, you can avoid them with your panel by moving all the breakers out to a subpanel & using Sum of Breakers rule / aka Hawaiian tie in), please confirm with SDGE or SCE that they will let you.

This approach isn't in the 18kpv manual.
1720482900629.png
 
might consider the Jesse Mueller line tap and interlock model, to avoid a big transfer switch
but still provides a method to power panel by grid or by inverter


 
The main goal for me is lowering our bill. Living in the hot SoCal foothills 110 heat this weekend and a 15month old sun and wife who stay at home our AC is the biggest driver of the energy consumption. If I just got that load off SCE and 100% powered by solar and my battery I would start working my way towards full ROI.
I’m in Arizona low desert on a plan similar to a NEM 3 plan you are likely to get in California. This makes payback periods long and unobtainable if not planned right.

If you can DIY it, or get good help from your friend, payback will be less.

There’s salesman that give pitches as if they have Nem1 favorable rates, but locally those rates have been gone for years.
 
Yes in my area NEM 3.0 with SCE they rip you off on power you sell back to them. So I'm not too concerned with being able to sell power back to the grid.
 

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