Adding a Second Solar Array

[sgeorgejr]

Hoping to get some help solving a problem I have with my current system. My current system is a grid tie10kw system with a maxed out solar edge inverter. The system was sized for my energy use before I purchased my Ford Lightning. My new system doesn't have the capacity to charge the truck and meet my home needs. I am looking for a cost effective way to add to the system. I have a second roof I can add another array too, but am not sure that is my best option. I read through some others with similar problems, but not really anyone who just added another solar system. My idea was to add another system to the other roof and and keep it completely separate from my current system. I am not sure if this is the best way to do it, but it seems cheaper than the poster who created a charging system with batteries. I hope I gave enough details.

 

[400bird]

Is your current system grid tied?
Adding a second grid tie system could probably cover your needs if you have a net metering agreement.

 

[sgeorgejr]

yes it is grid tied, and I do have Net metering.

 

[timselectric]

Then your agreement is the only limiting factor.
You have to stay within its limits.
I don't do grid-tied, someone else will have to provide further information.

 

[DIYrich]

My idea was to add another system to the other roof and and keep it completely separate from my current system. I am not sure if this is the best way to do it, but it seems cheaper than the poster who created a charging system with batteries. I hope I gave enough details.

A separate system would require inverter, batteries, and panels.

What do you currently have to charge the Ford?
What is your current inverter?
How much solar? Any open mppt available?
How much battery?
How can you get power between the garage and current inverter? How far?
How much solar do you want to add?

 

[sgeorgejr]

Hoping to get some help solving a problem I have with my current system. My current system is a grid tie10kw system with a maxed out solar edge inverter. The system was sized for my energy use before I purchased my Ford Lightning. My new system doesn't have the capacity to charge the truck and meet my home needs. I am looking for a cost effective way to add to the system. I have a second roof I can add another array too, but am not sure that is my best option. I read through some others with similar problems, but not really anyone who just added another solar system. My idea was to add another system to the other roof and and keep it completely separate from my current system. I am not sure if this is the best way to do it, but it seems cheaper than the poster who created a charging system with batteries. I hope I gave enough details

What do you currently have to charge the Ford?
I have the ford charger. It’s 80 amp right now.

What is your current inverter?
Solar edge se10000-is
How much solar?
It’s rated at 10.2kw
34 q cell panels
Any open mppt available?
Honestly not sure, how do I find this out?
How much battery?
I have 0 batteries except for my lightning battery which is 131kwh.
How can you get power between the garage and current inverter? How far?
I can run cable to the house under the driveway. It’s about 100ft from the garage to my panel.
How much solar do you want to add?
I want to add 4000kw. I can fit 12 panels easily. Depending on the panel size, but it I go with a second array, I will max the roof out. It’s a perfect south facing roof.

Thanks for the help!

 

[DIYrich]

Is the solaredge between the 80 amp charger and the grid? Or does the Solaredge just dump to the main panel?

Option 1: grid tied inverter. Take the 80 amp circuit as grid power to new inverter. Do a full setup in the garage (inverter, panels, battery). Dump excess solar back through the 80 amp wire.

You will need an eg4 18kpv or solark 15k to passthrough 80 amps from grid to charger. They will only provide around 50 amps from battery/solar.

 

[sgeorgejr]

Is the solaredge between the 80 amp charger and the grid? Or does the Solaredge just dump to the main panel?

Option 1: grid tied inverter. Take the 80 amp circuit as grid power to new inverter. Do a full setup in the garage (inverter, panels, battery). Dump excess solar back through the 80 amp wire.

You will need an eg4 18kpv or solark 15k to passthrough 80 amps from grid to charger. They will only provide around 50 amps from battery/solar.

The solar edge is not between the charger and the grid tie. There is no 80 amp in the garage, I park the car in the driveway and have it on the side of my house. Why do you think a battery is necessary? Can’t I just feed the grid and take it back when I need it?
I appreciate all your help.

 

[zanydroid]

The solar edge is not between the charger and the grid tie. There is no 80 amp in the garage, I park the car in the driveway and have it on the side of my house. Why do you think a battery is necessary? Can’t I just feed the grid and take it back when I need it?

You need to update your interconnection agreement to do this. And the answer to this depends 100% on your location and power company, so you need to provide that / do your own research (can be on other forums too).

So it is (largely) a legal/contractual limitation.

Apart from that, there is a busbar ampacity requirement that needs to be satisfied on the subpanels on the path to the power company, but this is easier to deal with than the law.

 

[#40Fan]

Why wouldn't a second off-grid sytem not work? I'd still add batteries to hold the extra juice the panels are making when the EV isn't plugged in though.

 

[DIYrich]

Why wouldn't a second off-grid sytem not work? I'd still add batteries to hold the extra juice the panels are making when the EV isn't plugged in though.

Start your own thread for your specific situation. Don't mess up someone else's thread.

 

[SunDave]

Start your own thread for your specific situation. Don't mess up someone else's thread.

Don't drink and post kids... I don't know if you didn't read it right, or are just having a bad day DIYrich, but #40Fan was posting about the OP's situation. If you don't like the info that's one thing, but coming off like this doesn't help either.

 

[DIYrich]

Don't drink and post kids... I don't know if you didn't read it right, or are just having a bad day DIYrich, but #40Fan was posting about the OP's situation. If you don't like the info that's one thing, but coming off like this doesn't help either.

OP doesn't want batteries, so it cannot be a separate system. Wants to net meter with the grid. Also, charging at 80 amps would require a huge separate system.

If #40fan wants a similar system, then the constraints may be different.

 

[DIYrich]

The solar edge is not between the charger and the grid tie. There is no 80 amp in the garage, I park the car in the driveway and have it on the side of my house. Why do you think a battery is necessary? Can’t I just feed the grid and take it back when I need it?
I appreciate all your help.

Small 2nd grid system would work. I would run the DC pv to where you have the solar edge, and put the 2nd inverter there.

 

[#40Fan]

Start your own thread for your specific situation. Don't mess up someone else's thread.

I would say you are way out in left field, but I think you got hit in the head when you were up to bat.

My idea was to add another system to the other roof and and keep it completely separate from my current system.

But, I will say the OP's other post was contradictory when asking...

Can’t I just feed the grid and take it back when I need it?

zanydroid answered that question though.

Nope, I'm not doing anything similar. Nothing in this thread is specific to my situation. Just stating/asking why an off-grid system, with batteries, wouldn't be the best way to go. EV is home, sun is blasting, charge away. Not home, fill up the batteries to use later. Does the OP need a full 80 amps when doing so? That is up to the OP and the amount of time during the sun blasting hours available.

 

[DIYrich]

Just stating/asking why an off-grid system, with batteries, wouldn't be the best way to go.

OP charges at 80 amps or 19.2kWh. That is a lot of inverter for a dedicated system. OP needs all of that to charge from empty to full overnight (131 kWh ev battery).

That's also a lot of battery storage. Assuming not great net metering, the best system for overnight charging is enough battery for regular use (50% of ev battery?), and let grid provide the rest. Inverter will need to be able to passthrough 80 amps, and export excess solar to the house or grid.

If you are going to have that much battery, you might as well wire the new inverter to backup the house. Use the solark 15k as the main inverter, and put the solar edge as ac pv into the solark.

Heck, I would design the system that way now. It would cost a few thousand more than a cheap grid inverter, but it would be really easy to add batteries later.

 

[DIYrich]

my lightning battery which is 131kwh.

I want to add 4000kw.

I assume you mean 4kw with 12 panels. In CT, that could generate 15kWh on average per day, or about 11% of the lightning battery.

CT has great net metering, so batteries would only be for backup. But, CT has the Energy Storage Solutions Program, which, along with the federal credit, can cover a good portion of the cost of a battery. Or, if you have the sol-ark or 18kpv installed, you can diy a battery cheap, and just take the federal credit.

 

[sgeorgejr]

Thanks for all the help, this is very valuable information.

I thought I can only federal tax credit once? I already did for my original array, so If i can take it again, that would be a game changer.

 

[DIYrich]

I thought I can only federal tax credit once? I already did for my original array, so If i can take it again, that would be a game changer.

If you add more solar and/or battery, you can take it again for the additional amount.

 

[zanydroid]

I thought I can only federal tax credit once? I already did for my original array, so If i can take it again, that would be a game changer.

You can get it as many times as you want, as long as the equipment has never had tax credit taken on it by previous owner