New Here: Building my first system and have some questions

[AlanGJP]

I've done a lot of research and am putting together my first system. I bought a home in rural Washington last November and am finally parting together the pieces to build my system. I'm on a level 1.12 acre property that is almost entirely free of trees. There's a deck attached to the back of our home that is almost large enough to fit the panels I purchased. I figured I'd explain what I'm trying to do and what I have. See if I messed this up or if I'm on the right track.

Things I've purchased:
2 x Eco-Worthy 5K Hybrid Inverter
4 x 280Ah 12V Eco-Worthy Batteries (12.34kWh)
24 x Eco-Worthy 410W Solar Panels
1 x Eco-Worthy battery balancer
1 x Victron MEGA fuse 200A/58V for 48V Products
1 x 20A Battery Charger
2AWG Cabling for the batteries to the inverter

Use Case:
Initially this would be used to charge our three EVs. (One is a PHEV)
Eventually I'd add additional batteries and maybe panels to also power the house/garage

Installation:
Most of the panels will replace the transparent roofing pieces on our large (attached) rear deck. I will likely have to expand this a bit onto the house above the deck, but everything should fit find there without too much trouble. I'll run that into the utility closet where our breaker box is. The two inverters will live in this room with the batteries. We have a detached garage with a 50A 240V connection to the house. I want to connect that to the output of the inverters and (for now) only power the detached garage.

I already have a level 2 and level 1 charger on the front of the garage, so I want to use those with this setup and also power the garage at the same time. The garage has a 240 sq ft attached office space, but uses very little power. (laptop, a few led lights, and a tv) I would also plug the inverters into the 240V that went to the currently connected garage to work as a backup for when solar is weak or unavailable.

Is this a solid plan? As it stands, nothing is connected. One inverter is still in it's box and I have yet to touch the panels. I did connect the 4 x 12V batteries, topped them off and connected to 120V in as a test, worked great. I'm wondering if I should set it up this way, or route the solar into the garage and connect everything there - which was the original plan until I considered that mounting the panels on the back deck made a lot of sense and would shorten the cable needed and since I'd eventually want to run the house off this, I'd be that much closer.

Anyone else with a similar setup? I'm thinking (at minimum) I need to add more fuses? One between the panels and input on the inverters. Anything else I'm missing?

Thanks so much, I've been a lurker for a long time, excited to be this close. I'm hoping to get this up and running to charge the vehicles before winter.

 

[Q-Dog]

Send the 12 volt batteries back ... and get 48 volt batteries for a 48 volt system.

 

[AlanGJP]

Send the 12 volt batteries back ... and get 48 volt batteries for a 48 volt system.

Unfortunately, I can't I've had it for almost a year and the return window is closed on that option. I do have space for the 12v batteries.

 

[Mattb4]

Not familiar with what it takes to run EV battery chargers but your PV system seems to have everything it takes to work but maybe not enough to be sufficient. You are in Washington State. If on the West side you likely will have trouble getting enough sunshine to make for a reliable system. 3 electric vehicles are a lot of load to supply.

I am sure it will be fun to see how it works out.

 

[AlanGJP]

Not familiar with what it takes to run EV battery chargers but your PV system seems to have everything it takes to work but maybe not enough to be sufficient. You are in Washington State. If on the West side you likely will have trouble getting enough sunshine to make for a reliable system. 3 electric vehicles are a lot of load to supply.

I am sure it will be fun to see how it works out.

Thanks for responding! So, the 4Xe is only around 15kwh and the only vehicle that will be completely drained daily. It’s also the one that’s here all day and can charge any time. My wife’s leaf will use maybe 10% of her charge and need to be topped up every day from around 4:30pm on, I’m thinking the batteries should be enough for that. My daughters bolt only really needs to charge on weekend and it would be plugged in all day. So I’m thinking we’d be right on the edge with these batteries.

So my first upgrade would be to add another four 280Ah to the mix, as needed.

My south view is completely unobstructed. So while I’m in WA, I do have a good southern view.

 

[MichaelK]

East side or West side? With ~10% output on cloudy/rainy days, of which the Seattle area will have 9 months of, you may not make more than 1000-1500W of power from October till May. That is not going to be enough to charge an EV 9 months out of the year. And it most certainly will not charge more than one EV!

For my own off-grid system, I currently have 6500W of panels online, making power, and I've never seen more that ~600W in the rain.

 

[Mattb4]

Thanks for responding! So, the 4Xe is only around 15kwh and the only vehicle that will be completely drained daily. It’s also the one that’s here all day and can charge any time. My wife’s leaf will use maybe 10% of her charge and need to be topped up every day from around 4:30pm on, I’m thinking the batteries should be enough for that. My daughters bolt only really needs to charge on weekend and it would be plugged in all day. So I’m thinking we’d be right on the edge with these batteries.

So my first upgrade would be to add another four 280Ah to the mix, as needed.

My south view is completely unobstructed. So while I’m in WA, I do have a good southern view.

Batteries are not the issue since they are simply storage (and load when discharged). Supply is the issue. That is why I asked if you lived in Western Washington or Eastern. West of the mountains has a lot of overcast days that will limit your ability to produce power. I grew up and lived in Western Washington until my 30's so am somewhat familiar with the Weather there.

 

[AlanGJP]

East side or West side? With ~10% output on cloudy/rainy days, of which the Seattle area will have 9 months of, you may not make more than 1000-1500W of power from October till May. That is not going to be enough to charge an EV 9 months out of the year. And it most certainly will not charge more than one EV!

For my own off-grid system, I currently have 6500W of panels online, making power, and I've never seen more that ~600W in the rain.

You’re right that on a dark rainy day here, you can see around 10% in the moment, I’d expect ~1 kW from my 9.84 kW array in those conditions.

But WA isn’t as cloudy as residents want you to believe - at least, not anymore. And that’s worst case, not daily or monthly production. PVWatts data for my location shows Oct–May I’ll still average ~16–33 kWh/day in the months between peak summer and deep winter, and ~7–10 kWh/day in the dead of winter — about 5 MWh total over those months.

That’s not enough to charge an EV from 0–100% every single day in winter if I were off-grid, sure, but I’m topping up, not refilling from empty, and a typical 30–50-mile day is ~9–16 kWh. Even in winter, that’s often mostly or fully covered. Grid-tied, I’ll still offset thousands of kWh a year in the gray months, and summer surplus will more than make up for the seasonal dip.

Saying “you won’t make more than 1,000–1,500 W from October to May” sounds dramatic because it takes the absolute worst moment in a rainstorm and acts like that’s the daily average. That’s just not how the math works.

 

[AlanGJP]

Batteries are not the issue since they are simply storage (and load when discharged). Supply is the issue. That is why I asked if you lived in Western Washington or Eastern. West of the mountains has a lot of overcast days that will limit your ability to produce power. I grew up and lived in Western Washington until my 30's so am somewhat familiar with the Weather there.

You’re right that supply is the key factor, but “West of the mountains” isn’t a constant wall of gray. My County averages about 2,172 hours of sunshine per year (~6 hours/day), with ~10 h/day in July and ~2 h/day in December. That’s a lot more than people remember from decades ago, and it’s already baked into PVWatts’ production estimates.

For my 9.84 kW array, PVWatts shows about 5 MWh from Oct–May alone — averaging 16–33 kWh/day in spring/fall and 7–10 kWh/day in winter. That’s seasonally lower, yes, but far from “barely producing.”

 

[AlanGJP]

Not sure what the goal is here. "You live in western Washington, forget solar"? I'm looking for help, not replies that imply I should just give up, or move...

 

[Mattb4]

Not sure what the goal is here. "You live in western Washington, forget solar"? I'm looking for help, not replies that imply I should just give up, or move...

Your first post asked "Is this a solid plan?" Establishing your solar potential and your loading is part of figuring out if it is.

So it is not about "give up or move". It comes down to will it work or not?

It also comes down to if you do not care if it works 100% at first eventually you will pound it into doing so. I am a big fan of doing things and seeing how it turns out. Now hold my beer.

 

[AlanGJP]

Your first post asked "Is this a solid plan?" Establishing your solar potential and your loading is part of figuring out if it is.

So it is not about "give up or move". It comes down to will it work or not?

It also comes down to if you do not care if it works 100% at first eventually you will pound it into doing so. I am a big fan of doing things and seeing how it turns out. Now hold my beer.

That question was with regard to pulling the feed from the house to the garage and connecting that to the output on the inverters. My concern is doing this might be a mistake. I'm not sure if connecting the output from two inverters into the garage 50A fused line makes sense, or if I should just place the whole thing in the garage.

I asked because I'd planned to eventually plug this into the whole house and placing the inverters where that would happen made sense. Just worried maybe I'm missing something.

As far as the vehicles, I went with hybrid inverters in case I needed grid to make up for the panels in the winter. I suspected winter would severely impact solar - from the get go. I have the room and can always add more solar in the future. I thought 24 x 410W would be a good launching point.

 

[MichaelK]

I lived in Washington and Oregon for more than a decade, and I had the green shoes to prove it. My numbers are based on real-world production on cloudy/rainy days, not guestimates. If you won't accept those, then good luck to you.

 

[max2k]

That question was with regard to pulling the feed from the house to the garage and connecting that to the output on the inverters. My concern is doing this might be a mistake. I'm not sure if connecting the output from two inverters into the garage 50A fused line makes sense, or if I should just place the whole thing in the garage.

I asked because I'd planned to eventually plug this into the whole house and placing the inverters where that would happen made sense. Just worried maybe I'm missing something.

As far as the vehicles, I went with hybrid inverters in case I needed grid to make up for the panels in the winter. I suspected winter would severely impact solar - from the get go. I have the room and can always add more solar in the future. I thought 24 x 410W would be a good launching point.

it appears to me you're missing the main component: the actual energy - all that equipment would not help if the Sun is not shining. You'd need much larger array to satisfy your needs at which point it won't make any financial sense multiple times over. As was already pointed out the design starts from calculating your energy consumption then moving to calculating array size using pvwatts site then you'd realize not every place on Earth is good for solar. Batteries can only store the energy but it needs to come from somewhere first.