from-nibly
New Member
Hey everyone,
I hope this isn't inappropriate but I'm at the very beginning stages of designing a power setup for a community I'm going to be building starting in the 2-4 years. There are lots of details to figure out and one of them is power. I could really use some help figuring a few things out. Any questions that you can answer would be greatly appreciated. I'm coming from an assumption that I'd be using sol-arks (cause they SEEM straighforward) but I'm open to whatever.
Background:
I'm planning on building a community of up to 10 houses. I'm trying to figure out if it makes more sense to build 1 "plant" for each house, or make a single large power plant in a central community space and distribute the power from there. The 1 "plant" per house seems straight forward enough. Get a sol-ark 15k (or whatever) and hook it up to some batteries and a propane generator, store it all in a shed (venting the generator with a fire safe exhaust, and then do normal electrical work to the house and inside the house.
The large power plant that distributes however...
Self Warning
I'm not an electrical engineer, my brother-in-law is, but he's not a civil engineer. If there are things listed below that should be reviewed/engineered by a licensed engineer please let me know, I don't want to kill myself or anyone else.
So here are the things I'm thinking about
3 phase vs 2 phase
I've heard that 3 phase is a lot easier to balance the load between houses so I think it would make sense to use 3 phase instead of single phase with all the houses/buildings I'm planning. That would probably mean using something like sol-ark 30k
Transmission lines
I've done some rough voltage drop calculations using an online calculator. All the houses should be within 500 feet of a central point where I can put the "plant".
If I use 480v step up/down transformers I should be able to span 500 feet with 2/0 AWG aluminum triplex easy peasy. Those can obviously be pretty expensive new, but I've seen a lot of pretty beefy stuff on ebay used. (is that a good way to get myself killed?)
(120v / 480v) * 125amp = 36amp, which results in a 1.26% voltage drop according to this
www.calculator.net
According to ugly's electrical reference 2/0 AWG should be able to handle 115 amps (way more than 36 that would be carried)
Question 1:
Am I able to use 1 huge transformer on the plant side of things, hook that up to a distribution box (with breakers) and then send individual wires to each house? Then have smaller transformer at each house to step down the voltage?
Batteries:
One big issue, is that sol-arks, can only have 1 battery bank. I've seen some stuff on this forum about using a separate charge controller for big battery banks, but I feel like I'm missing something.
I think that means that they can only have the maximum of what a single sol-ark can connect, right?
Question 2:
Does that mean I can only distribute 30kw from batteries when the sun goes down even if I have 5 30k's all hooked up?
If so what's the point of being able to hook up 5 sol-arks in parallel to each other?
Question 3:
Am I better off building/designing my own solar setup with things like victron components where everything is separate?
Generator Backup:
For generator backup sol-arks have switching built into them, but similarly to batteries I believe they have some limits.
Question 4:
Can you hook up a generator to each sol-ark when you have 5 or so connected together?
Anway sorry for the wall of text, even if I can only get some answers on a few of these questions I would be extremely greatful.
I hope this isn't inappropriate but I'm at the very beginning stages of designing a power setup for a community I'm going to be building starting in the 2-4 years. There are lots of details to figure out and one of them is power. I could really use some help figuring a few things out. Any questions that you can answer would be greatly appreciated. I'm coming from an assumption that I'd be using sol-arks (cause they SEEM straighforward) but I'm open to whatever.
Background:
I'm planning on building a community of up to 10 houses. I'm trying to figure out if it makes more sense to build 1 "plant" for each house, or make a single large power plant in a central community space and distribute the power from there. The 1 "plant" per house seems straight forward enough. Get a sol-ark 15k (or whatever) and hook it up to some batteries and a propane generator, store it all in a shed (venting the generator with a fire safe exhaust, and then do normal electrical work to the house and inside the house.
The large power plant that distributes however...
Self Warning
I'm not an electrical engineer, my brother-in-law is, but he's not a civil engineer. If there are things listed below that should be reviewed/engineered by a licensed engineer please let me know, I don't want to kill myself or anyone else.
So here are the things I'm thinking about
3 phase vs 2 phase
I've heard that 3 phase is a lot easier to balance the load between houses so I think it would make sense to use 3 phase instead of single phase with all the houses/buildings I'm planning. That would probably mean using something like sol-ark 30k
Transmission lines
I've done some rough voltage drop calculations using an online calculator. All the houses should be within 500 feet of a central point where I can put the "plant".
If I use 480v step up/down transformers I should be able to span 500 feet with 2/0 AWG aluminum triplex easy peasy. Those can obviously be pretty expensive new, but I've seen a lot of pretty beefy stuff on ebay used. (is that a good way to get myself killed?)
(120v / 480v) * 125amp = 36amp, which results in a 1.26% voltage drop according to this
Voltage Drop Calculator
This free voltage drop calculator estimates the voltage drop of an electrical circuit based on the wire size, distance, and anticipated load current.

According to ugly's electrical reference 2/0 AWG should be able to handle 115 amps (way more than 36 that would be carried)
Question 1:
Am I able to use 1 huge transformer on the plant side of things, hook that up to a distribution box (with breakers) and then send individual wires to each house? Then have smaller transformer at each house to step down the voltage?
Batteries:
One big issue, is that sol-arks, can only have 1 battery bank. I've seen some stuff on this forum about using a separate charge controller for big battery banks, but I feel like I'm missing something.
I think that means that they can only have the maximum of what a single sol-ark can connect, right?
Question 2:
Does that mean I can only distribute 30kw from batteries when the sun goes down even if I have 5 30k's all hooked up?
If so what's the point of being able to hook up 5 sol-arks in parallel to each other?
Question 3:
Am I better off building/designing my own solar setup with things like victron components where everything is separate?
Generator Backup:
For generator backup sol-arks have switching built into them, but similarly to batteries I believe they have some limits.
Question 4:
Can you hook up a generator to each sol-ark when you have 5 or so connected together?
Anway sorry for the wall of text, even if I can only get some answers on a few of these questions I would be extremely greatful.