Finally, the start of my 25kw Ground Mount grid-tie system

[Hedges]

200 feet is significant but not troublesome. You're better off mounting the inverters right to the solar array and run a single large gauge 240 volt 4-wire line back to the house.

The inverter accepts up to 600VDC, so I would make the wire run with PV DC, not AC.
If multiple strings to be combined, you can have the combiner at the array. If you are paralleling multiple strings of different orientations, less IR drop for a given total wire cross-section that way.

If you mount the inverters to the home, you need to install rapid shutdown stuff, which can get really expensive fast.

If the panels aren't on the roof, segmentation between panels shouldn't be needed.
At most, disconnect of power from the inverter. A simple switch would rapidly shut down DC power to the inverter.
But if wires are in conduit into the inverter, I don't think RSD applies. If it does, put the inverter on a fence post adjacent to the house.

 

[live4soccer7]

The inverter accepts up to 600VDC, so I would make the wire run with PV DC, not AC.
If multiple strings to be combined, you can have the combiner at the array. If you are paralleling multiple strings of different orientations, less IR drop for a given total wire cross-section that way.




If the panels aren't on the roof, segmentation between panels shouldn't be needed.
At most, disconnect of power from the inverter. A simple switch would rapidly shut down DC power to the inverter.
But if wires are in conduit into the inverter, I don't think RSD applies. If it does, put the inverter on a fence post adjacent to the house.

This is what my original thought was as well. transfer the current with the higher voltage. It should be more efficient and if the pricing at the store I linked to is valid then I can get pv wire much cheaper than wire to carry the 240v.

I was also thinking the same thing. Just mount all the inverters on a post structure. That way you don't have it attached to the structure. I will be making some calls this week to the local utility company and count permitting office to get some questions answered. With the fronius inverters, I can go up to 800vDC. That would be even more beneficial. Again, still some information to be collected before I can get too far into decisions on specific equipment.

 

[Hedges]

Standard wire in conduit is fine for up to 600V PV runs.

https://www.lowes.com/pl/TFFN-thhn-wire-Electrical-wire-cable-Electrical/4294546249

800V PV may or may not be accepted for consumer installations - check building department. I thought 600V was consumer and 1000V was commercial. (But the headroom, for cold weather, would let you push array higher.)
I don't think there is a problem with inverter on wall of the house, fed by conduit from remote array and no RSD, check that too.

Make the conduit way oversize for easier pulling. Don't believe the conduit fill charts - just because it is allowed doesn't mean it is possible (except for a short straight run you can push wire through.

Make sure your choice of GT PV inverter does frequency-watts, so you can AC couple it to a battery for backup/off-grid in the future.

 

[live4soccer7]

Standard wire in conduit is fine for up to 600V PV runs.

https://www.lowes.com/pl/TFFN-thhn-wire-Electrical-wire-cable-Electrical/4294546249

800V PV may or may not be accepted for consumer installations - check building department. I thought 600V was consumer and 1000V was commercial. (But the headroom, for cold weather, would let you push array higher.)
I don't think there is a problem with inverter on wall of the house, fed by conduit from remote array and no RSD, check that too.

Make the conduit way oversize for easier pulling. Don't believe the conduit fill charts - just because it is allowed doesn't mean it is possible (except for a short straight run you can push wire through.

Make sure your choice of GT PV inverter does frequency-watts, so you can AC couple it to a battery for backup/off-grid in the future.

Thanks! Hopefully I will have some more "ammunition" after I get a hold of the relevant parties that have answers to these things for my area. I'll post up what I find out.

 

[wattmatters]

Are the connectors on the back of the panels traditionally long enough to be able to connect to the panel next to it without extending them?

Yes.

Just mount all the inverters on a post structure. That way you don't have it attached to the structure.

It's a really good idea to make sure inverters are protected from the elements and have good air flow for heat dissipation. Keep the inverter out of the sun, and preferably protected from rain/snow (and vermin if they are an issue looking for somewhere warm to snuggle in). A cover of some sort is a good idea.

800V PV may or may not be accepted for consumer installations - check building department. I thought 600V was consumer and 1000V was commercial.

Yes, check the DC limits in your area. Here we are limited to 600V residential. If you can go higher than be very selective about what DC breakers you use.

High voltage DC is a bastard to cut off. Way more dangerous and difficult than AC. 800V at 20+A is not something to putting a cheap breaker on. It will arc and can easily start a fire.

The normal shut down procedure is to cut AC power to the inverter(s) first, then isolate the DC side once the inverter is off and no more current is flowing. If DC side has to be broken first while operating in the daytime (for whatever reason, hopefully only ever in an emergency) then you will want to make sure it's very good breaker well capable of handling a break at those voltages and currents.

 

[live4soccer7]

@wattmatters Thank you very much for the great information. Where I'm planning on putting them will keep them out of the elements for the most part and the sun as well. It is on the north side of my building.

Hopefully I can have answers to a lot of these questions tomorrow or the next day.

I do know a local solar installer quoted me on an installed 30kw system using the fronius primo 15kw inverters, which tells me that our DC limit is probably 1000vDC since the normal/optimal operating range on those goes up to 800v with a max of 1000v.

 

[live4soccer7]

I should be receiving an email from the county with additional code information. What I have so far:

Wind: Min 85MPH
Snow: Min: 39lb/ft^2
Frost: 24"

I gave "thepowerstore.com" a call today to "pick their brains" and hopefully get some suggestions. The sales rep gave me pricing that was better than the site and is also quoting me on panels as well with freight included and going to provide me her suggesting on the most cost effective ground mount system from their perspective. All in all, I was very happy with the call. She is going to write me up an official quote and send it over soon.

She said they sell a lot of the solis inverters and she has no known issues with them. Granted, she is a sales person so you kind of have to take that with a grain of salt. But $1400 for 10kw inverter is pretty dang cheap.

This is the panel they are quoting me on as well:

PowerStore | Wholesale Solar Inverters, Grid-Tied Solar

PowerStore provides a one-stop shop for wholesale solar products, including grid-tied solar, off-grid solar, and solar storage solutions. Same-day shipping. Shop now!

thepowerstore.com

Even the web advertised price is cheaper than what I'm getting anywhere else. Hopefully the quoted price is a bit cheaper since I would be getting 80-100 of them.

Just waiting on information now before I can move forward with more calls/planning.

 

[live4soccer7]

I'm trying to find a link I had open for a while. It had the top panel brands each year and showed how many years they had "won". Anyone know what site I'm referring to?

 

[whatwhatcom]

I'm trying to find a link I had open for a while. It had the top panel brands each year and showed how many years they had "won". Anyone know what site I'm referring to?

Long-time lurker here, moving to Western WA soon and watching this with great interest, we have 1 acre there and want to outfit a ground-mount system too. Thanks for all the great information in the thread!

You posted in Post #21 this thread:

Top Performers | 2023 PVEL PV Module Reliability Scorecard

See which manufacturers earned Top Performer recognition from PV Evolution Labs (PVEL) in the 2023 PV Module Reliability Scorecard Summary.

modulescorecard.pvel.com

Is that the one?

 

[live4soccer7]

Long-time lurker here, moving to Western WA soon and watching this with great interest, we have 1 acre there and want to outfit a ground-mount system too. Thanks for all the great information in the thread!

You posted in Post #21 this site:

Top Performers | 2023 PVEL PV Module Reliability Scorecard

See which manufacturers earned Top Performer recognition from PV Evolution Labs (PVEL) in the 2023 PV Module Reliability Scorecard Summary.

modulescorecard.pvel.com

Is that the one?

hahahha. yeah, that's the one. I might be losing my mind over here.

Fantastic, TRINA is the top rated panel brand over the years. Good enough for me. Hopefully the price thepowerstore provides is undoubtedly the best. That will really push me to get the find details figured out and get this thing in motion.

 

[whatwhatcom]

Here are some pics of the bluesun solar mount system. It comes in at about half the price of sunmodo, unirac, or iron ridge. Wind rating of just under 100mph and snow load of 30lbs/sqft.

One of the concerns I see with it is that the brackets are held into the concrete by bolts instead of a post being set into concrete. This is a 30kw system from blue sun in Cincinnati. Seems like the arrays should be farther apart based on what we talked about already in this post, but that not really the point. Any input on this mounting system? I think the ironridge with 3" pipe is the best option, but I am trying to keep costs down where possible without compromising the system.

How does pricing out with the Bluesun Solar Mount system work, which web site do you use and do you just call them up to get a quote? I've been going through the IronRidge configurator and it's pretty slick, but the system seems pricey, even when I get the BOM and price out each piece.

I'm looking at used cells for now with the capability to swap out later for newer cells when I can afford it. But I don't want to hurt anyone with flying solar cells with too cheap a rack.

 

[live4soccer7]

How does pricing out with the Bluesun Solar Mount system work, which web site do you use and do you just call them up to get a quote? I've been going through the IronRidge configurator and it's pretty slick, but the system seems pricey, even when I get the BOM and price out each piece.

I'm looking at used cells for now with the capability to swap out later for newer cells when I can afford it. But I don't want to hurt anyone with flying solar cells with too cheap a rack.

You can probably get the ironridge stuff or other mounts cheaper through CEDgreentech as they should shave $$ off the MSRP you see on the builders.

The system from bluesun was about $5500 for 40kw worth of panels. Probably tack another $1-2k for freight and then you still have to do concrete. They DO NOT have stamped engineering plans for you like sunmodo, unirac, and ironridge. I'm pretty sure I have to have engineer approved plans for permitting in my area, so that is a problem for me. I'm trying to confirm a bunch of information with the county though as I plan this whole thing.

I REALLY wanted to keep this at about $1/W when finished, but highly doubt that will happen.

 

[wattmatters]

Fantastic, TRINA is the top rated panel brand over the years.

Trina in Australia has a good reputation. They are not premium end panels like LG but they make good quality value for money product and here in Australia at least they are known for standing behind their warranty. Some years ago they had a batch of failing panels but without issue they replaced every single one they knew about. Installers here rate them as a favourite because of the mix of performance, price and they know backup will be there if ever it's needed.

I have Trina panels on my roof, somewhat older technology at 275W each but that was more common back when my system went up. Would be nice if they were closer to 400W!

 

[live4soccer7]

Trina in Australia has a good reputation. They are not premium end panels like LG but they make good quality value for money product and here in Australia at least they are known for standing behind their warranty. Some years ago they had a batch of failing panels but without issue they replaced every single one they knew about. Installers here rate them as a favourite because of the mix of performance, price and they know backup will be there if ever it's needed.

I have Trina panels on my roof, somewhat older technology at 275W each but that was more common back when my system went up. Would be nice if they were closer to 400W!

Great to know. I'm looking at the 415W ones. We will see what the quote comes back as.

 

[live4soccer7]

@whatwhatcom I just realized you said you were moving to western WA. It's a great area, welcome! I wanted to do this about 5 years ago, but decided to put it on the back burner until now for various reasons.

Alright. Just a little new info, not too much.

I got a quote back from thepowerstore. They quoted $320 for 1000' of single conductor 10gauge 2000v wire. I haven't seen a lower price.
$1395 for the solis 10k inverters - I don't see frequency-watts in the documentation though.
Panels were quoted at $192 (415W Trina).

With that panel pricing, I will likely go with the Hyundai bifacial 450W panels for about $200. I'll get more power and have a smaller foot print. I'll also save on freight. Freight for all those items was about $1000.

I'm working on chasing down a copy of the latest or close to the latest of NEC NFPA book for pv/solar stuff. I found an older copy, but I don't want to rely on that.

I'm also still waiting to hear back from the county permitting office.

 

[whatwhatcom]

@whatwhatcom I just realized you said you were moving to western WA. It's a great area, welcome! I wanted to do this about 5 years ago, but decided to put it on the back burner until now for various reasons.

[...]

With that panel pricing, I will likely go with the Hyundai bifacial 450W panels for about $200. I'll get more power and have a smaller foot print. I'll also save on freight. Freight for all those items was about $1000.

Thanks! We're super excited about the move.

For the Hyundai bifacial 450W panels - we're likely starting out with used panels but would you mind sharing the local vendor who has those 450W panels? Going local would be my preference for shopping in general - and that seems like a decent deal compared to what we're seeing online anyway, especially factoring in freight.

 

[Hedges]

I got a quote back from thepowerstore. They quoted $320 for 1000' of single conductor 10gauge 2000v wire. I haven't seen a lower price.

Not bad. I see $265 for two 500' spools 10 awg stranded THHN from Home Depo. Those are 600V.
If you are allowed to run higher voltage, that will reduce losses.

Cerrowire 500 ft. 10 Gauge Black Stranded Copper THHN Wire 112-3871J - The Home Depot

Complete your indoor wiring project with this 500 ft. Black 10-Gauge Stranded THHN Single-Conductor Electrical Wire. Its copper strands can handle up to 600-Volt. It is sheathed in PVC and nylon.

www.homedepot.com

You should have a ground wire too, for the frames. It wouldn't be subject to the same voltage and probably only needs to be sized for Isc, not for voltage drop. Without ground wire, a short could apply voltage across the dirt, conduct current through it. Great for catching nightcrawlers!

I got spools of red and black 6 awg earlier for a lower price, now it would be $344 to get a spool of white. From eBay, $330 with delivery.

Cerrowire 500 ft. 6 Gauge White Stranded Copper THHN Wire 112-4202J - The Home Depot

Cerro's building wire is created primarily for use in commercial and industrial wiring as specified in the NEC, including use in conduit and cable trays for service, feeders and branch circuits as well

www.homedepot.com

Now isn't a great time to be buying copper.

 

[live4soccer7]

Thanks for all the info! I'm definitely going to be shopping around on all components. The wire just needs to be THHN? and then the rated DC voltage or higher, obviously. I've seen nothing so far that says I can't go up to 1000v. Yeah, right now sucks for wire and steel. Unfortunately, those are both decent chunks to the project. I'm hoping prices drop a little over the next couple months.

@whatwhatcom CEDgreentech They will have those panels in at the end of OCT to the beginning of NOV. I wouldn't be surprised if they came in a little later due to the container shipping issues/delays that have been happening.

 

[live4soccer7]

Wesbell wiring has quoted me $420/1000' of red and black 2000v 7 strand "PV" wire. So, that is 1000 of each color for that price, to clarify.

 

[live4soccer7]

Wesbell Wiring: $420/1000' 2kv wiring (includes 1000' of black and red)
Panels CEDgreentech: $220 hyundai 450W Bifacial OR $190 + freight on Trina 415W panels from thepowerstore
Inverters: $1400 SOLIS 10kw or ? (frequency-watts)
Ground Mount: ???
MC4 Connectors: Bluesun $1 for a set of mating connectors.

For the MC4 connectors, I shouldn't need a lot of them since the panels all connect to each other. I would think I would just need 2 connectors per string. Is this correct or am I missing something?

Will frequency watts ONLY be found on the hybrid controllers?