Thoughts and ideas on this system setup...

[Integraolig]

Hey all,
Been researching a new system for a while now and with the increase to a 30% tax rebate, I'm all in this year.

A bit about my home, average 1,500kwh per mo. Panels will be a Ground Mount located 5' from the main breaker pole. We have a dedicated electrical pole outside that the meter is on, which is also the main breaker (200amp). At that main breaker it distributes to 3 circuits. Line 1 goes to a sub-panel in the home (100amp). Line 2 goes to the well pump. Line 3 goes to the HVAC (which is a heat pump system, the condenser is run from the sub-panel in the home while the rest of the system and backup heat is ran from line 3).

I was originally looking at a sting inverter (Sol-Ark 12k)... but have found that this inverter really needs to be inside the home along with the battery system. So having to run the lines from the panels to the inverter inside, and new main lines from the meter (grid) inside to the inverter... then from the inverter back out to the main breaker where the meter is, is really redundant and far to run the lines.

Question 1
Then I found the Enphase IQ8. As these are made to stay outside on the back of the panels, then goes into a combiner box (which is also good to stay outside) this seems like our best option. The only lines we'd need to run into the house is for the battery system. Correct?

Question 2
I'm getting conflicting information about the IQ Combiner Box 4 being the only networked item I need... while others say that I not only need the combiner box but also the "Communications Kit". To my understanding, the IQ Combiner box already has the Communications Kit basically built into it. Which is correct?

Question 3
How much of a power variation should I be looking at from the panel to the microinverter? I was thinking of going with Jinko JKM405M-72HL-V panels which at SCT is 405w. But the largest output microinverter is the IQ8H which is 384w. I read somewhere that 30w lower microinveter to panel wattage is the norm. But I'm just seeing this as wasted wattage. Shouldn't these match closer? Like a 380w panel with the 384w IQ8H?

Thanks all!

 

[nc73]

Your avg kwh hour might be a bit off....If not you're quite the energy hog or a really large mansion.

 

[Integraolig]

Sorry, one to many zero's. It's corrected now. 1500kwh per mo.
Thanks!

 

[Ampster]

How much of a power variation should I be looking at from the panel to the microinverter? I was thinking of going with Jinko JKM405M-72HL-V panels which at SCT is 405w. But the largest output microinverter is the IQ8H which is 384w. I read somewhere that 30w lower microinveter to panel wattage is the norm. But I'm just seeing this as wasted wattage. Shouldn't these match closer? Like a 380w panel with the 384w IQ8H?

DC to AC ratios greater that 1 to 1 are common because panels rarely peak at there nameplate capacity. Enphase has tables to help. It is important to not exceed the voltage specs of the inverter. My IQ7s have maximum output of 290 Watts and I have the connected to 345 Watt panels. That is a DC to AC ratio of 1.2 to 1.

 

[Integraolig]

DC to AC ratios greater that 1 to 1 are common because panels rarely peak at there nameplate capacity. Enphase has tables to help. It is important to not exceed the voltage specs of the inverter. My IQ7s have maximum output of 290 Watts and I have the connected to 345 Watt panels. That is a DC to AC ratio of 1.2 to 1.

I came across this "calculator" on the Enphase site.

IQ Microinverter compatibility calculator | Enphase

enphase.com

All it tells you when you enter the panel info is what IQ8 version will work and no other info. Do you know where the tables are located?

 

[Ampster]

Do you know where the tables are located?

https://support.enphase.com/s/article/IQ8-and-IQ8plus-Microinverters-Datasheet

 

[Integraolig]

Ah the datasheets, yes I've looked at each of them. I thought you were referring to a table that showed the best DC-AC ratio for each of the units.

Do you also use the IQ Combiner Box 4? And if so, other then the Combiner box, panels and IC7 units... are there any other devices in your system?

 

[Ampster]

I thought you were referring to a table that showed the best DC-AC ratio for each of the units.

There is no "best" DC-AC ratio, there may be an optimal one base on a use case. For example, if I wanted more generation in winter I would have gone with larger panels for my IQ7s. The higher ratio would have had clipping in summer but better output than my existing panels. In my case the system size permitted by my utility provider is based on inverter capacity and that also drives the busbar loading rules. So if there was a constraint there I might have spent the money for a higher DC-AC ratio

Do you also use the IQ Combiner Box 4? And if so, other then the Combiner box, panels and IC7 units... are there any other devices in your system?

I do not use a combiner box. I had the Envoy from a previous system. I have two strings and I also wanted the flexibility of moving one string to my main service panel if my hybrid could not handle the capacity of both strings when AC coupled. I am going to add four used Sunpower panels to a new string of IQ7+ micros and that will probably go to the main service panel.
I do use the consumption CTs and I also have an Emporia Energy monitor which gives me a check on the Enphase production numbers. The rest of my system is in my signature.