Single SolarEdge inverter for two buildings?

[ringi]

Can I use a single SolarEdge inverter for both the house and a deteched garage that is about 10m away?   If so what sort of cable needs to be connected to the garage and how does it need protecting?

 

I have East and West facing roof on the single garage with South,East and West on the house,  (also North facing roof on the house that I expect I will not use).

 

Is there any issues with the SolarEdge per panel micro inverters with roof integrated PV?

 

As the work will be combined with a re-roof and I have some shading I am thinking as many panels as possible make sense using the ability for SolarEdge to have double the panel capacity then inverter output.

 

 

[joth]

In principle this is quite possible but suitability will depend on a lot of factors.

 

The normal way is to install PV high voltage cable inside flexible steel conduit like

https://www.tlc-direct.co.uk/Products/LFLS20slash10.html

How many cores will depend how many strings are being exported to the other building.

 

 

 

[Dillsue]

4 hours ago, ringi said:

Can I use a single SolarEdge inverter for both the house and a detected garage that is about 10m away? 

Yes. Max cable length for a single string is 300m so you'll likely be able to wire a house and nearby garage within that length. You might find it easier to run two strings, one for the house and one for the garage. There's a minimum number of optimisers per string which is 8 or 6 depending on the optimisers youre using- see the optimiser data sheet. We used 6mm 2 core SWA for external wiring from garage to ground array, check the cables DC voltage rating is higher that the SE string max.

 

There's a limit to the inverters DC input so worth checking you're not exceeding that, but I dont think it's double the AC power rating. I did read somewhere recently that the limit had been lifted so definitely worth checking. 

Edited February 16, 2023 by Dillsue

[ringi]

1 hour ago, Dillsue said:

You might find it easier to run two strings, one for the house and one for the garage

 

So this is likely showing my misunderstanding, but I though SolarEdge only had a single input to the inverter that all optimisors/panels are connected to, unlike other makes that often have two optimisors in the inverter with two sets of connectors.

[Nickfromwales]

Optimisers go on the panels. This allows each panel to function independently, and for any shaded ones to never interfere with overall maximum efficiency.

Are you looking to DIY this? If not, it's probably a good idea to get an MCS accredited designer to run an eye over your ideas first. You can get these done for free, so well worth the money     

[Dillsue]

11 hours ago, ringi said:

 

So this is likely showing my misunderstanding, but I though SolarEdge only had a single input to the inverter that all optimisors/panels are connected to, unlike other makes that often have two optimisors in the inverter with two sets of connectors.

Assuming you got an SE3680H or smaller inverter, if you take the cover off youll likely see 2 pairs of terminals for the DC connection. One pair is used and the other is spare. There's also space on the bottom of the inverter for a second pair of MC4 connectors to be fitted so its easy to add a second pair of connectors if you want. If you look at the larger inverters they have 2 pairs of MC4 connectors as standard. I think the rationale is that the smaller inverters can normally be installed with a single string of 25 x optimisers whereas larger inverters need dual strings to get to max capacity.

 

Instead of adding extra connectors to the inverter you can parallel up the strings using an MC4 Y piece or a junction box. If you get a big enough DC isolator you can parallel up there which is how my original 2 string MCS install was done

[Conor]

12 hours ago, ringi said:

 

So this is likely showing my misunderstanding, but I though SolarEdge only had a single input to the inverter that all optimisors/panels are connected to, unlike other makes that often have two optimisors in the inverter with two sets of connectors.

No, my solar edge Inverter has connections for two strings. Optimisers fine in the in-roof tray system.

[ringi]

10 hours ago, Dillsue said:

Assuming you got an SE3680H or smaller inverter, if you take the cover off youll likely see 2 pairs of terminals for the DC connection. One pair is used and the other is spare. There's also space on the bottom of the inverter for a second pair of MC4 connectors to be fitted so its easy to add a second pair of connectors if you want. If you look at the larger inverters they have 2 pairs of MC4 connectors as standard. I think the rationale is that the smaller inverters can normally be installed with a single string of 25 x optimisers whereas larger inverters need dual strings to get to max capacity.

 

Instead of adding extra connectors to the inverter you can parallel up the strings using an MC4 Y piece or a junction box. If you get a big enough DC isolator you can parallel up there which is how my original 2 string MCS install was done

 

Thanks, how does the system keep both strings at the same voltage so they can be connected in parallel?

[Dillsue]

9 hours ago, ringi said:

 

Thanks, how does the system keep both strings at the same voltage so they can be connected in parallel?

I beleive the optimisers on each string regulate that strings voltage. You have to have compatible optimisers on each string so they can work together correctly and a minimum number of optimisers to ensure minimum voltages are reached. If youre planning on mixing optimisers, SE produce a compatibilty table that shows which models can go on the same string