West facing panel idea?

[cdherman]

I have a perfect south facing roof. But its over 400 feet from the main loads. I would potentially need 200A service in the distant shed, have to move the entrance pole and meter to the shed, if I wanted a hybrid system with battery backup of the whole enterprise. After doing some calculations, perhaps this is a bad idea. The economics are that an extra $5000 in panels on a west facing roof that is very close to the loads would be cheaper than the wiring to the more distant shed. Is my logic correct?

What's more, I am reading that west panels may be better from a grid standpoint, as peak loads, especially in summer are 4-8ish. Although my utility does not have TOU at this time, it could change.

BTW, both sheds are large agricultural structures. Total installed PV could go as high as 30k or more, but the utility at this time says they will only permit a grid tie system that is sized by PVwatts to cover average monthly loads. They have concerns about too much power going back into their grid. It is a small customer owned cooperative, and they are generally reasonable, though a little alterative energy adverse. In any case, I want plan the system with future expansion as an option, but inital size, at least in terms of panels, will be modest. I think PVwatts says 8k will cover our needs. Although a Ford Lightning is arriving in a month, so electricity use will rise.

 

[MichaelK]

Do the panels have to be mounted on the roofs? Why not ground mounts? Here's a pic of a mount I designed and built, that can hold six large, residential panels. Suppose you mounted six 72-cell panels, putting out 37.5V each. Six would reach 225VDC, and even at a distance of 400', you only loss about 8V, using standard 10-gauge wire.

 

[cdherman]

Lots of stuff on a sprawling farm. 39.683199480952695, -98.90626198609057 If curious. There are a lot of things at ground level that can cause problems for stuff. Huge machines moving around. Cows. Weeds to mow, or some sort of ground cover like crushed rock which is not free.

But the idea of remotely locating the panels and running the high voltage DC back to a better location is interesting. I will read more. I have several roofs that are available......

 

[740GLE]

I guess you’re not worried about mountains or terrain ?

I personally like the idea of western or south wester panels, as it’s usually hotter from 12 to 5pm, so my AC is probably working harder. Not sure how your loads are through the day.

Also planning for TOU rates is a very good idea.

 

[Zwy]

Lots of stuff on a sprawling farm. 39.683199480952695, -98.90626198609057 If curious. There are a lot of things at ground level that can cause problems for stuff. Huge machines moving around. Cows. Weeds to mow, or some sort of ground cover like crushed rock which is not free.

But the idea of remotely locating the panels and running the high voltage DC back to a better location is interesting. I will read more. I have several roofs that are available......

How tall is the tallest bin? Where is service panel located now?

I went here and inputted 15 meters high for what appears to be the tallest bin. I'd take out those trees behind the house on the south edge of the trees and put a ground mount in there. Even if the barn was 45 feet tall, it won't matter for that location on winter solstice, Dec 21st.

SunCalc sun position- und sun phases calculator

Application for determining the course of the sun at a desired time and place with interactive map.

www.suncalc.org

 

[cdherman]

How tall is the tallest bin? Where is service panel located now?

I went here and inputted 15 meters high for what appears to be the tallest bin. I'd take out those trees behind the house on the south edge of the trees and put a ground mount in there. Even if the barn was 45 feet tall, it won't matter for that location on winter solstice, Dec 21st.

SunCalc sun position- und sun phases calculator

Application for determining the course of the sun at a desired time and place with interactive map.

www.suncalc.org

I'm impressed! Those bins are old, short, mostly empty, though one still has drying capacity, which means like a 15 hp motor that to be fair would never be ran off solar or backup. The bins hardly ever impact insolation. Big grain storage is elsewhere. But it means that I have to have 200A pass through off grid in whatever solution I devise. Also, the farmstead sits on the edge of a property line. Everything to the west is not ours. So cannot go there.

As for ground mounting -- if you look at the last satellite views, you might catch the semi-trailer flat bed next to the shed. That is just one of may things that pull onto the place for refueling, refills etc. Its really a business, as are all real farms these days. Those machines need space. Really cannot take anything away. There is acres and acres around and about. But spending 10s of thousands on cable is a little painful too.

There is no single service panel. The meter pole has multiple breakers and one generator interconnect that precedes them all. The gen set switch is 200A. To make matters worse, to clear out space in 1980, for a new house and changing size of equipment, the old meter pole was moved. But underground in the vast "white area" in the satellite view, are multiple crisscrossing wires.....

Today, the grid is still the cheapest option. I am not doing this for making money, but I'd like to do it anyhow for a variety of reasons.

Perhaps we should blow things up and really rethink all the wiring. Except its not a great time to be purchasing a lot of heavy wires.....

 

[Craig]

Compare the price if you use a solar charger or all in one that can handle 500 volts of PV I think this will save you time and money. I like to use 8 guage welding wire which isnt all that expensive. How many amps or total watts are you expecting from your solar panels.

 

[timselectric]

Compare the price if you use a solar charger or all in one that can handle 500 volts of PV I think this will save you time and money. I like to use 8 guage welding wire which isnt all that expensive. How many amps or total watts are you expecting from your solar panels.

All of the welding wire I have seen is only rated for 300v. Where are you getting yours?

 

[Craig]

All of the welding wire I have seen is only rated for 300v. Where are you getting yours?

Mine says 600 Volts

https://www.amazon.com/Gauge-Welding-Battery-Copper-Flexible/dp/B01MTALFA1?th=1

 

[timselectric]

Mine says 600 Volts

https://www.amazon.com/Gauge-Welding-Battery-Copper-Flexible/dp/B01MTALFA1?th=1

Sweet, thanks.

 

[Zwy]

I'm impressed! Those bins are old, short, mostly empty, though one still has drying capacity, which means like a 15 hp motor that to be fair would never be ran off solar or backup. The bins hardly ever impact insolation. Big grain storage is elsewhere. But it means that I have to have 200A pass through off grid in whatever solution I devise. Also, the farmstead sits on the edge of a property line. Everything to the west is not ours. So cannot go there.

As for ground mounting -- if you look at the last satellite views, you might catch the semi-trailer flat bed next to the shed. That is just one of may things that pull onto the place for refueling, refills etc. Its really a business, as are all real farms these days. Those machines need space. Really cannot take anything away. There is acres and acres around and about. But spending 10s of thousands on cable is a little painful too.

There is no single service panel. The meter pole has multiple breakers and one generator interconnect that precedes them all. The gen set switch is 200A. To make matters worse, to clear out space in 1980, for a new house and changing size of equipment, the old meter pole was moved. But underground in the vast "white area" in the satellite view, are multiple crisscrossing wires.....

Today, the grid is still the cheapest option. I am not doing this for making money, but I'd like to do it anyhow for a variety of reasons.

Perhaps we should blow things up and really rethink all the wiring. Except its not a great time to be purchasing a lot of heavy wires.....

You didn't answer any of my questions.

If you are planning on a very large array, then you should move to the cow pasture which is open to the south. I'm not a huge fan of roof mounted solar if there is any snow during winter. I am a huge fan of seasonal tilt of ground mounts, again snow is a huge factor plus yield is better in winter.

Distance from array to SCC's or inverters can be managed by higher string voltages and up sizing wire slightly, however one needs to compare cost of larger wire to just adding more panels and accepting some loss due to voltage drop. That is for off grid, if grid tie then it most likely will be micro inverters.

The location west of the house shouldn't be an issue for a small array to run a house. It is out of traffic and has good sun. Distance is minimal to the house. You haven't really stated your needs or whether you are looking at grid tie, emergency UPS for the house or to run the house off grid or a system to run much of the farmstead (which would most likely need to be grid tie). If this is to run the house off grid, you only need to go to the house main panel area to add a system to the house most likely with a manual transfer switch.

If you are running overhead wire and were to go grid tie, the utility will require an upgrade to the main service panel for the whole farm. The 120% rule applies and the utility will want an upgraded meter/socket. If the system is tied in at the meter socket, you might be able to circumvent the 120% rule on the main panel at the meter. If not, plan on rewiring the whole farmstead with underground while you upgrade the main panel/meter socket. That is the time to do it. Electrical wire will not get any cheaper any time soon. The war is part of the reason but there is huge demand for wind/solar in commercial size due to Inflation Reduction Act tax incentives and people are adopting solar for their personal property to take advantage of the IRA. One thing about the IRA, if you have to upgrade much of your current main panel for the farmstead, you get a 15% tax credit the first year plus the depreciation for that first year for income tax purposes on the farmstead. So if you need a tax break for a really profitable year, this is big benefit.

 

[Zwy]

Sweet, thanks.

It's cheaper direct from Windy Nation. https://www.windynation.com/collections/welding-battery-cable

Any battery/welding cable I used has always been rated for 600V. Not sure where you are getting 300V cable but that would be a red flag to me on purchasing it.

 

[timselectric]

Not sure where you are getting 300V cable but that would be a red flag to me on purchasing it.

That's what the local shipyard I worked at, always had in stock. The maintenance crew would always try to use it for temporary power. (480v)
I was always ripping it out and smacking them on the back of their heads. lol

 

[740GLE]

They’ll learn their own mistakes, you can’t prevent stupid.

 

[timselectric]

They closed 4 years ago. It was sad to see that happen. 900 people lost their job. And my old boss took it as a good time to retire. So, I took all of my customers and started my own company.

 

[cdherman]

Hey guys, thanks for input.

-- grid tie, though hybrid with battery backup is a temptation, or just a grid tie to save some money. In any scenario heavy loads would normally be covered by the grid.
-- ground mount is out of the question.
-- I don't own anything west of the house and trees in western KS take decades to grow. No way they get removed.

But I still have not got a taker on the discussion west orientation of panels. Rest of internet seems to have a smattering of discussion how it might be useful, since it increases production late in the day.

The furthest north building has a quite steel south facing roof. It also would be an excellent candidate for a new meter pole, and location for an AIO such as Sol-arc 15 or EG4 18. The large shed to the south, in the middle, has the west facing roof in question. A string of panels on BOTH roofs, one steep south facing (winter) and one more flat west (Summer) might give a nice mix, but the DC high voltage lines would have to travel about 125' . Underground between those two sheds is a kind of a nightmare of criss crossing water and power lines.

But the idea of tying two sets of panels together, with the AIO in the north, right where we can have a 200A pass through to the reset of the utility. Very clean. I will read more on the DV HV line requirements.

Last question that brings up: Can I put DC high voltage lines in the same trench as AC? Separated by a layer of sand maybe?

 

[Zwy]

Hey guys, thanks for input.

-- grid tie, though hybrid with battery backup is a temptation, or just a grid tie to save some money. In any scenario heavy loads would normally be covered by the grid.

You better talk to your utility first. Then talk to your electrician about upgrade to service panel you will need. 120% rule applies.

-- ground mount is out of the question.

It can get expensive high in the air. Who gets to service/repair after the install?

-- I don't own anything west of the house and trees in western KS take decades to grow. No way they get removed.

It would depend on the size of the array. I was referring to only a few on the south end, just north of the shadow line.

If those are ash, consider the trees dead already. I have 20 on my acreage, everyone has EAB and will be cut down. I started with 7 last year.

But I still have not got a taker on the discussion west orientation of panels. Rest of internet seems to have a smattering of discussion how it might be useful, since it increases production late in the day.

East/west orientation will produce longer thru the day but will not yield as much as direct south facing. The second problem is roof mount will not be a good angle to the sun horizon early/late in the day. It will take a much larger array, more wiring, etc. No free lunch.

The furthest north building has a quite steel south facing roof. It also would be an excellent candidate for a new meter pole, and location for an AIO such as Sol-arc 15 or EG4 18. The large shed to the south, in the middle, has the west facing roof in question. A string of panels on BOTH roofs, one steep south facing (winter) and one more flat west (Summer) might give a nice mix, but the DC high voltage lines would have to travel about 125' . Underground between those two sheds is a kind of a nightmare of criss crossing water and power lines.

But the idea of tying two sets of panels together, with the AIO in the north, right where we can have a 200A pass through to the reset of the utility. Very clean. I will read more on the DV HV line requirements.

Last question that brings up: Can I put DC high voltage lines in the same trench as AC? Separated by a layer of sand maybe?

Run pvc conduit for the DC high voltage and use non perforated drain tile for the AC. I installed direct burial 4/0 for my shop and wish instead I had a tile it ran thru. Around here, any new bins, sheds, and outbuildings, everyone uses non perf tile.

I've been to farms where there was a large grain storage setup and the line was direct burial in between bins on the original installation. Whole yard dug up, driveways dug up less than 10 years later. A huge mess.

 

[cdherman]

I am less interested in discussing load panel upgrades. We don't run the majority of the loads from a single panel or sub panels and the utility has been OK with that for years. So please leave that out of the discussion. I understand that continuous use things need 80% derated. But talking about upgrading panels is really not where we are at. Ditto trees and ground mounts. (Trees are NOT Ash -- Burr Oak, 400 year "design life" so to speak.) I will figure out the load panels when the time comes.

I asked for advice primarily about west facing arrays. Several internet sources have suggested only a 15% loss. It occurs to me that I already understand and can use PVWatts to make some of those calculations. I will do so and answer my own question. I though originally I might stimulate some useful discussion about TOU and loads on the grid.......

This installation is going in, in a place where there are hardly any electricians and no solar installers. I've already been talking personally to the utility. I get it Mr Zwy, you think I don't know anything. But I actually do. BTW -- the farm owns a telehandler with a 55' high reach and 10k lb limit (less at 55'). I think we can install and service some #40 panels. We have a 8x12' work deck for the telehandler. Utility asks for a plan to approve. If you work with them and take their advice, they are able to help un-licensed people put stuff in to their satisfaction. Because that is what happens here.

I DO MUCH appreciate the conduit idea's. IRRC you have to be careful what you put in a conduit. And a "repurposed drainage tile" kind of sounds like poor mans conduit. But the idea is great, cause the thought to traversing that driveway/yard several times is a night mare. Putting both in one trench would be nice. Currently the middle large building is fed overhead from the current meter pole. But that arrangement has been begging for correction for years, as it is exposed to lightning and accidental contacts. One trench, hellish to complete, but a longer term solution would be great.

 

[740GLE]

Sounds like you know your answer. Go with a west facing array of it suits your construction and site plans.

If you find the west facing array needs a little juice, you could always add a small south facing array to capture more of that morning sun.