Off-grid solar for new development (Campground+Two Yurts), thanks for any help!

cdnorth

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John Frum

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Totally new to all of this, where does the 4800 feet come from? Thanks for all the help!
You need 3 wires out and 3 wires back.
400 feet * 6 conductors = 2400 feet.
My mistake will do the math again.
 

John Frum

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2/0 awg for 2.48% voltage drop for the furthest yurt
1 awg for 2.97% voltage drop for the closer yurt
 

John Frum

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Those yurts don't need ~6000 watts continuous.
Not comfortable to give you a number on how much over subscription you can get away with.
Honestly this project is above my pay grade.
 

John Frum

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Thanks for all the help, this gives us an idea of the range of what we are looking at so we can determine what path we want to go. Any thoughts on the equipment?
Actually much of what I said last night was wrong.

I looked at things again today.

Here is what I came up with
I suggest you use 4 of the all in one boxes to create 120/240 split phase electricity.
Even though all your consumers are 120 volts it helps with the distance.
Might be better to just buy a 1000 foot spool of 2-2-2-4 and sell the un-used bit.
Code:
wire
    https://www.wireandcableyourway.com/4-4-4-4-tulsa-underground-secondary-distribution-cable
    https://www.wireandcableyourway.com/2-2-2-4-dyke-underground-secondary-distribution-cable
breakers
    https://www.se.com/ca/en/product/QO2100/mini-circuit-breaker%2C-qo%2C-100a%2C-2-pole%2C-120-240vac%2C-10ka%2C-plug-in-mount/
    ~$100.00CAD
scenarios
    home run wiring
        main_panel {
            |->yurt1(300 feet)
            |->yurt2(400 feet)
        }
        25amps to each yurt
        main_panel->yurt1
            4-4-4-4
            $1.62USD per foot = $486.00USD
            100 amp double pole breaker
        main_panel->yurt2
            2-2-2-4
            $1.96USD per foot = $784.00USD
            100 amp double pole breaker
    daisy_chain wiring
        main_panel {
            |->yurt1->yurt2
        }
        yurt1 {
            |->yurt2
        }
        50 amps from main_panel to yurt1(300 feet)
            2-2-2-4 $588.00USD
            100 amp double pole breaker
            1.54% drop
        25 amps from yurt1 to yurt2(100 feet)
            4-4-4-4 $162.00USD
            100 amp double pole breaker
            0.82% drop
 

iamrich

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This sounds like a fun project. Basic questions first:

Is any grid power available (Assuming no)?
Do you need AC for the yurts?
What is the "Main Facility?"

I think your tankless water heater calculation is way low on amperage unless it is a tiny unit?
 

cdnorth

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Hello, thanks for taking a look at this and providing your thoughts, much appreciated!

Grid power is available but it's quite a distance away and we were quoted at 75k-100k to bring it in.

We were planning to have everything at 110V in the yurts but are open to any suggestions.

By "main facility" I am saying the central facility that will have four combination restroom/shower rooms, a small kitchen/coffee area, a small office and a storage area. In addition, all of the camping sites are included with the "main facility" as well ( these will have a few lights and connections for folks to plug in electronics). Basically, we have this main facility area plus the two yurts (12 camping sites, central area and two yurts total).

Regarding the tankless water heater, this will be propane, what amperage do these units typically draw if this seems low? The central restroom unit will be larger but nothing crazy and each yurt will have a fairly small unit.

Hopefully this helps clarify, let me know your thoughts and if you have any other questions, I agree that it's a fun project! :)
 

John Frum

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We were planning to have everything at 110V in the yurts but are open to any suggestions.
You can still have everything at 120VAC in the yurts and still do 120/240VAC split phase transmission.
Doubling the voltage, halves the amperage which means you can use thinner(cheaper) wire.
Also doubling the voltage, halves the voltage drop as a percentage.
 

cdnorth

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You can still have everything at 120VAC in the yurts and still do 120/240VAC split phase transmission.
Doubling the voltage, halves the amperage which means you can use thinner(cheaper) wire.
Yes, thanks again, for some reason I never got a notification of your response but thanks for putting all of that together! It may take me a minute to piece it all together in my head but definitely makes sense to run 240V!
 

iamrich

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Hello, thanks for taking a look at this and providing your thoughts, much appreciated!

Grid power is available but it's quite a distance away and we were quoted at 75k-100k to bring it in.
Not worth it. But... if you could trench your way in with even a single 20amp circuit, it would open up your options. We will discard this though.
We were planning to have everything at 110V in the yurts but are open to any suggestions.
I think this is best
By "main facility" I am saying the central facility that will have four combination restroom/shower rooms, a small kitchen/coffee area, a small office and a storage area.
I would add a mechanical room to hide everything. This would be the core facility, but you could also run the same setup on each yurt, especially if you can work a fixed mechanical room onto each yurt (even a closet size one). I think tent when I hear Yurt, but I am not sure what you will be building these out of.

In addition, all of the camping sites are included with the "main facility" as well ( these will have a few lights and connections for folks to plug in electronics). Basically, we have this main facility area plus the two yurts (12 camping sites, central area and two yurts total).
I would just run a breaker box/distribution panel for the campsites and bury everything in conduit. You will not need much power for this assuming you are going to let your patrons know that they can't run 12 gigawatts worth of crap. It's camping after all :)
Regarding the tankless water heater, this will be propane, what amperage do these units typically draw if this seems low? The central restroom unit will be larger but nothing crazy and each yurt will have a fairly small unit.
That works, but you have to vent them. I was thinking pure electric. The demand for electric is like 5000w for a decent flow rate, and you are feeding four showers.
 

iamrich

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Maybe two MPP 6548 for the main building. That will give you 13kw of power to run everything (120v single phase) which should be plenty I think. Run this off the biggest battery array you can manage and the biggest solar array you can manage. Each unit has 2 solar charge controllers, so I would max them out (4kw each) and point each array in a slightly different direction (South East, South, South West assuming northern hemisphere). That way you start getting power early and keep getting it all day long. 16kw array should net you at least 50kw a day I would think. Supplement with a small (very quiet) generator (2-3000w). The generator can run all day, so it doesn't have to get it done all at once.

Then I would run a single 6548 for each yurt with a single 5kwh battery pack. That will run a mini split AC and all of your other needs and the 5kw should give you an hour buffer at constant use. You would hook the AC in side to the main building, so you really only need to run a single 10awg line from the main compound to the yurt. That would give you 20-30a of charging (24/7) from the main building.

Repeat the above for Yurt 2

If you can add more solar to the main building, just add PCM-60x's for each 3kw or so of array you can add. Batteries just keep adding as you can afford them. I like the EG4 batteries for simplicity, but at $1500 a pop they are expensive compare to DIY cells.
 

50ShadesOfDirt

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I'd tend to want autonomy between all the structures (yurts, camping sites) ...

One yurt going in now, one later, possibly same for some number of rv sites. With each having their own system, nobody impacts anybody else; one site down, the other sites keep going. Nobody takes more power than their independent system can offer to them.

This seems to save all kinds of trenching costs, wire runs, over-sizing of systems, etc? Adds reliability in a fashion? Possibly savings for buying multiples of a component?
 

iamrich

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I'd tend to want autonomy between all the structures (yurts, camping sites) ...

One yurt going in now, one later, possibly same for some number of rv sites. With each having their own system, nobody impacts anybody else; one site down, the other sites keep going. Nobody takes more power than their independent system can offer to them.

This seems to save all kinds of trenching costs, wire runs, over-sizing of systems, etc? Adds reliability in a fashion? Possibly savings for buying multiples of a component?
I think the panel array will be the issue. I doubt someone wants a 10kw panel array next to their campsite, but I definitely agree with the autonomy idea.
 

iamrich

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4. Is there a real difference between solar panels? The ones that were quoted were significantly more expensive than what we are seeing on signature solar or similar and I can't imagine that there's much of a difference. I'm sure this is just what he's the most comfortable installing and I've asked the question and I'm sure he won't have a problem installing any type. I'm just curious if there's anything we should be keeping away from.
You are going to be completely off grid. I would run used panels (250w seems to be the best bang for the buck) and a lot of them if you have the real estate. You can get used 250w panels for $50-60 (sometime less) in USA, so that is 5kw for $1000 (plus ground mount racking). $5000 will get you a 20kw array that you can point in multiple directions and you can just keep adding on as you have time/money.
 

cdnorth

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Not worth it. But... if you could trench your way in with even a single 20amp circuit, it would open up your options. We will discard this though.

I think this is best

I would add a mechanical room to hide everything. This would be the core facility, but you could also run the same setup on each yurt, especially if you can work a fixed mechanical room onto each yurt (even a closet size one). I think tent when I hear Yurt, but I am not sure what you will be building these out of.


I would just run a breaker box/distribution panel for the campsites and bury everything in conduit. You will not need much power for this assuming you are going to let your patrons know that they can't run 12 gigawatts worth of crap. It's camping after all :)

That works, but you have to vent them. I was thinking pure electric. The demand for electric is like 5000w for a decent flow rate, and you are feeding four showers.

Thanks so much for all the feedback, I think off grid makes the most sense and it gives us something extra to educate guests on which is cool as well! I've already planned in a small mechanical room that we will use to store all equipment, the water heater and some cleaning supplies in each yurt and a large storage area in the main facility that we can section off for mechanical equipment. Yes, the individual we were talking too was suggesting that we limit each site to 5A to minimize the likelihood of overloading. I'm not entirely sure what route we'll go there but the good news is we will be starting with 4-6 camp sites and can evaluate for a season and figure out what we need to do when we build out the rest! For the water heater, we'll either vent or place it outdoors.
 
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