1000' run from good solar site to house/shop - Questions

[KalebTheMaker]

Hi everyone,

On my property, my house and shop site are north-facing, but just down the hill, I have a great site that is south-facing and will get plenty of sun all year. The issue is that "just down the hill" is about 1000 feet. There is a road, so it would be easy to trench through. I have a backup site that currently (end of November) will see about 4-5 hours of sun, but that may go away completely by Solstice. I am keeping an eye on it to see if it will be feasible.

My question to you all is, if I have to run 1000' of conductors, should I put all of my gear close to the panels, and run AC up the long run, or put all my gear up near the house/shop and run DC on the long run? The question mostly is a long run more efficient/better-in-some-way on AC or DC?

I am looking at a 240v split-phase system @ ~60A, and about 10Kw of panels. Min/Max temps here: 20F / 115F. The solar setup is not done yet, still in the research phase and trying to work out this issue.

Thanks,
-Kaleb

 

[MurphyGuy]

If it was me, I'd put the grid-tied inverters near the solar array and then use a couple of transformers to kick the voltage up to 480 and then back down again at the house.

Is this 1000 feet of conductors or 1000 feet away from the house?

Is this a grid tied system or off-grid?

If you have to run wire to carry a 60 amp load a 1000 feet, the wire is going to cost you more than the actual solar system..

 

[MurphyGuy]

You might also consider finding an inverter/charge controller that can take a really high mppt input in the 600 to 1000 volt range, then just run smaller DC conductors at that high voltage.

That would also save you from having to install 3 full size wires running that far.

 

[KalebTheMaker]

Hi there,

It's 1000' along the road. A bit shorter line of sight, but would have to trench through *lots* of roots and rough terrain.

Fully off-grid. No grid-tie option.

Not quite that expensive, but close! If I did AC (two hots, common and ground - 4 conductors) it's something like $10/ft.

And that is exactly what I was thinking. If I can find something that high of volt range, If can run high voltage DC up the 1000' and have my equipment up near the house and shop the conductor gauge goes way down. I am currently looking at Victron, and their highest mppt input is 450v (as far as I can tell), so I might have to do two of those (and 4 conductors again, but smaller gauge).

Or am I missing something?

Thanks,
-Kaleb

 

[Zwy]

Hi everyone,

On my property, my house and shop site are north-facing, but just down the hill, I have a great site that is south-facing and will get plenty of sun all year. The issue is that "just down the hill" is about 1000 feet. There is a road, so it would be easy to trench through. I have a backup site that currently (end of November) will see about 4-5 hours of sun, but that may go away completely by Solstice. I am keeping an eye on it to see if it will be feasible.

My question to you all is, if I have to run 1000' of conductors, should I put all of my gear close to the panels, and run AC up the long run, or put all my gear up near the house/shop and run DC on the long run? The question mostly is a long run more efficient/better-in-some-way on AC or DC?

I am looking at a 240v split-phase system @ ~60A, and about 10Kw of panels. Min/Max temps here: 20F / 115F. The solar setup is not done yet, still in the research phase and trying to work out this issue.

Thanks,
-Kaleb

The trick is higher voltage and less amperage. Higher amps lead to more power loss which is current squared x wire resistance.

I have 420+ feet from array to EG4. I had 2 LV6548's (purchased before the EG4 came out) but changed the array location and glad I did. The problem with the LV6548's was 250VOC limit and needing 4 strings instead of 2. It also would require 8AWG due to voltage drop. With the EG4, 2 strings at around 400VOC and I could use 10AWG. Cost for 8AWG would have been $2500, 10AWG cost me under $700 with some special deals.

Did it cost me? Yep, that's the price of education. https://diysolarforum.com/threads/design-changes-and-the-associated-costs.49469/

 

[Chriskruger]

Convert to AC near your panels … then run it to your load. Keep it simple … power consumption in transformers would negate any gain doing step up and down transformers. Running heavy gauge dc wire to near the load b4 inverting is un economic and just stupidity.

 

[timselectric]

Definitely DC

 

[timselectric]

Convert to AC near your panels … then run it to your load. Keep it simple … power consumption in transformers would negate any gain doing step up and down transformers. Running heavy gauge dc wire to near the load b4 inverting is un economic and just stupidity.

DC would be high voltage. (Smaller wire)
A lot less expensive. And way more efficient.

 

[Shimmy]

How many kW are you looking at for PV? I would want the batteries to not be at the PV array for sure.

For ground mount, you might even go with a 1000VDC system, although I would put the charge controller outside the house for sure.

 

[KalebTheMaker]

DC would be high voltage. (Smaller wire)
A lot less expensive. And way more efficient.

This is exactly why I wanted to post this here. I have had mixed answers from people when I have spoken to them in person. Some people say go AC, and some say go DC.

Tim, this makes sense to me, and it's the way I am leaning currently. But then I hear answers like @Chriskruger saying that AC is the way to go.

 

[KalebTheMaker]

Convert to AC near your panels … then run it to your load. Keep it simple … power consumption in transformers would negate any gain doing step up and down transformers. Running heavy gauge dc wire to near the load b4 inverting is un economic and just stupidity.

Hi @Chriskruger , thanks for the reply. I don't understand how it's uneconomic if running DC would be smaller gauge wire. Can you explain, I seem to be missing something.

Thanks,
-Kaleb

 

[timselectric]

This is exactly why I wanted to post this here. I have had mixed answers from people when I have spoken to them in person. Some people say go AC, and some say go DC.

Tim, this makes sense to me, and it's the way I am leaning currently. But then I hear answers like @Chriskruger saying that AC is the way to go.

DC also suffers less voltage drop over long distance.
And it is better to keep the rest of your equipment together and close to the loads.

 

[KalebTheMaker]

How many kW are you looking at for PV? I would want the batteries to not be at the PV array for sure.

For ground mount, you might even go with a 1000VDC system, although I would put the charge controller outside the house for sure.

Hi Shimmy, ~10kW PV array. I am most likely going to build a "power shed" that is close, but not inside the house or shop.

 

[timselectric]

Hi Shimmy, ~10kW PV array. I am most likely going to build a "power shed" that is close, but not inside the house or shop.

Keep in mind that the equipment is going to last longer. If it's kept in a clean temperature and humidity controlled environment.

 

[pvdude]

My main PV is about 250 ft from the building w/ the electronics.
The MPPT charge controllers are good for up to 550vdc.
I ran #10 THHN in conduit, DC voltage drop is only a few volts, works great!

 

[KalebTheMaker]

Keep in mind that the equipment is going to last longer. If it's kept in a clean temperature and humidity controlled environment.

For sure. When I say "shed", I mean it only as an outbuilding. It will most likely be cinderblock (high fire hazard area) and clean inside. Only use will be for these electronic components.

 

[timselectric]

For sure. When I say "shed", I mean it only as an outbuilding. It will most likely be cinderblock (high fire hazard area) and clean inside. Only use will be for these electronic components.

What type of battery?
Why high fire Hazzard?

 

[42OhmsPA]

Another vote for high voltage DC run.
The below may suffice. Don't forget safety when working with high voltage DC and decent current...

Schneider Electric Conext MPPT Solar Charge Controllers

The Conext MPPT solar charge controllers come in 60A, 80A, and now 100A models. Get the most power out of your home solar system and improve battery life!

www.altestore.com

Edit - I still consider myself a rookie but no longer a noobie ?

 

[KalebTheMaker]

What type of battery?
Why high fire Hazzard?

Looking at either SOK 48v 100Ah Racks, or I have a connection with KiloVault. Just getting started looking at their solutions. Either way, they will be LiFePo4.

All of Northern California == High Fire Hazard.

 

[KalebTheMaker]

Another vote for high voltage DC run.
The below may suffice. Don't forget safety when working with high voltage DC and decent current...

Schneider Electric Conext MPPT Solar Charge Controllers

The Conext MPPT solar charge controllers come in 60A, 80A, and now 100A models. Get the most power out of your home solar system and improve battery life!

www.altestore.com

Edit - I still consider myself a rookie but no longer a noobie ?

I was just looking at that same link! Thanks!