Three solar systems, switchover?

[Shale MacGregor]

Currently considering three separate solar arrays and inverters for my home. One system on workshop , one system on pool house, and one system on house.

The workshop would have 16KW of panels and 80kWh of storage, the pool house would have 5KW and 20;kWh of storage , the house would have 14KW of panels and 60kWh of storage.

Primarily I would like the shop to be able to power the pool equipment when needed, and as a backup be able to power the house. I would not need the house to power the other two.

Thoughts or advice?

 

[FilterGuy]

Why separate systems? Why not one big system?

 

[toms]

socomec make fully programmable transfer switches that can be remotely switched.

i use a manual transfer switch between my two systems.

i have one house system, and one workshop / desalination plant system.

two systems are comforting for redundancy in the event of component failure

i have a third system also, but it is in a cabin that is 500metres from our house.

 

[Shale MacGregor]

Why separate systems? Why not one big system?

House is a roof-ac microinverter system grid tie currently, adding the back two myself and need power at each location and storage / climate control in one, I guess I could run the DC from the pool house panels back to the workshop, then run AC from the workshop up to the pool house.

 

[time2roll]

As long as energy is moving in just one direction a standard transfer switch will work fine.

 

[Shale MacGregor]

As long as energy is moving in just one direction a standard transfer switch will work fine.

So as long as I cut off one supply before turning another one on?

 

[time2roll]

So as long as I cut off one supply before turning another one on?

That is what a transfer switch does. If the home has it’s own power the relay connects the home inverter. If the home loses power the switch defaults back to workshop power.

same for the pool.

 

[Shale MacGregor]

That is what a transfer switch does. If the home has it’s own power the relay connects the home inverter. If the home loses power the switch defaults back to workshop power.

same for the pool.

Are there transfer switches where you can connect 3 or 4 sources, and prioritize them?

 

[time2roll]

Are there transfer switches where you can connect 3 or 4 sources, and prioritize them?

Not that I know of.
Although the switches can be stacked in sequence. Priority would be based on the sequence of the sources connected. Again power can only go one direction.

Although it would be interesting to see if all could be wired into a loop.

 

[Shale MacGregor]

Not that I know of.
Although the switches can be stacked in sequence. Priority would be based on the sequence of the sources connected. Again power can only go one direction.

Although it would be interesting to see if all could be wired into a loop.

I am confused by power can only go one direction. My inverters on the roof tie directly into the panel, the grid can take a ebb/flow, but my generator cannot. Is there also a device to put in between to prevent accidental backfeed on the sources that are simultaneously supplying current to pick up the slack ?

 

[time2roll]

Are all grid connected? One generator at the shop?

 

[Hedges]

Are there transfer switches where you can connect 3 or 4 sources, and prioritize them?

Mostly I see 2:1 switch. You could cascade several of those.


If you wanted to go the expensive route, and assuming your PV inverters do frequency-shift, SMA's Sunny Island battery inverters each establish and island grid, and multiple of these can play together with a "multi-cluster" that takes the place of utility grid.

 

[Shale MacGregor]

Are all grid connected? One generator at the shop?

Shop has no grid AC, poolhouse is fed by a 90 amp breaker off of the main panel at the house. Generator is very very rarely used and it is in main panel at house with a protected shutoff so you have to have grid off to turn it on

 

[time2roll]

Ok you already have a lockout at the house and it feeds the pool. Pull wire from the shop to the house and connect to the generator feeder with a transfer switch. The switch will allow generator or shop to feed power to the house but keep shop power and generator isolated.