Solar pv's got me thinking

[SuffolkFarmerboy]

Hello one for you electricians out there
Ok so ...On a small farm which I work which we have 100amp 3phase head supplying 2barns. We also have a onsite 100amp 3phase generator with automatic start on mains failure.
We are now looking in to have the barns covered in split pv
My wuestion is How would solar pv work if we was running on the generator ? Where would the spare electric produced go?! Would this mess up are generator having power fed back into it
Thanks in advance guys

 

[flameport]

When the mains (grid) fails, the solar inverter shuts down.
No mains power = no solar power either.

The fact you have a generator doesn't make any difference - the generator would never be connected to the solar equipment.

 

[DetlefSchmitz]

(Not an electrician)


Unless the PV wanted to supply less than the barn load at the time the generators went on, the PV inverter would not start up, or would turn off. If the inverter turns off there will be no 'spare' electricity. Unless your supply cuts off regularly it shouldn't be an issue that you get no PV power during an electricity cut.

 

[SuffolkFarmerboy]

How does the inverter know its the grid and nOt generator supply though , think I might be missing some thing here

 

[RF Lighting]

It will have monitors for grid power and shut down when this is not present.

Your generator change-over switch will have grid & PV supply as input 1, and generator as input 2.

The grid & pv supply and the generator supply are entirely seperate and they are never at any point connected together.

 

[SuffolkFarmerboy]

Ok Iam defrently sticking to farming this is well confusing ha
So the set up look like below

Grid-----main fuse-----changeover switch--------busbar------fuseboxs
....................................... ^............................^.................
..............................,......generator supply.........solar pv

 

[bernardgreen]

A client raised this a year ago as the installer company surveyor had no idea whether the generator "would complicate things". The "surveyor" had never experienced a generator back up system before. For the invertor proposed it was found to be necessary to inform the invertor that the supply it was getting was from a generator and thus not attempt to feed in any excess. If I recall correctly the entire PV system would have had to be shut down when the generatior was running. As a result of this confusion and some mis-leading ( over optimistic ) figures of financial return the system was not installed.

 

[flameport]

[code:1]

fusebox------solar
|
|
Grid-----------main fuse-----changeover switch-----fusebox
|
|
Generator

[/code:1]
Meters and some other items not shown.