Help Please. SolarEdge Inverter - Off Grid Solution

[faceplant]

HI all I am Dave and I live in Spain.

I have just had a brand new three phase solar edge system put in. However to my surprise they failed to mention to me that this inverter SE10K-RWS48BEN4 is not capable of going off grid. I have 16Kw of battery and I recently purchased an ID BUZZ so I was looking to utilise these for full battery back up of the house.

Does anyone have any ideas on how I can take though house off grid in the event of an outage,

Thanks for your help with this.

Dave
(Feeling like he's bought a dud)

 

[SeaGal]

From a quick search, it would appear that your inverter is grid-tie only. The manual mentions "For backup power an inverter specifically designed for backup applications is required; this inverter is not in the scope of this document."

My first thought is what was specified and agreed with the installers? And, hence, is there an option to reject the installation that doesn't meet the agreed functionality?

Second thought is that a grid tie inverter is designed to power down if there is no grid voltage, so I don't see an easy way around getting your SE to provide backup power in an outage situation.

I'm sure someone somewhere has found a workaround for doing that (I'm musing whether you could have an isolated system with an off-grid inverter tricking the SE into thinking it is connected to a grid (whilst obviously fully isolated from the real grid)), but no idea if that would work or what the legalities in Spain would be. Also being 3ph would add complications to such a bodge workaround.

 

[timselectric]

You will need a separate hybrid AIO.
To use battery and the existing grid-tied inverter.
Make sure that you choose one that is capable of AC coupling.

 

[Brett V]

You will need a separate hybrid AIO.
To use battery and the existing grid-tied inverter.
Make sure that you choose one that is capable of AC coupling.

What about the SE optimizers? Is there a way to trick them in to an ON condition without the SE inverter, or will they have to be removed?

 

[timselectric]

What about the SE optimizers? Is there a way to trick them in to an ON condition without the SE inverter, or will they have to be removed?

The problem isn't tricking the inverters to produce.
It's controlling their production.
Grid-tied inverters are designed to run wide open at all times. Without any control, or somewhere to send the power (the grid, usually). It will just burn up anything connected to it.

 

[donTommazo]

Hi. Did you find a solution to this? Wouldn't the SolarEdge Home Backup Interface 3-ph give you the backup functionality you are looking for?

 

[kommando]

The current inverter cannot provide an AC output without reference to another AC supply. You can trick it into thinking it's still connected to the grid by using a small inverter with a high quality AC output but first you need to ensure you disconnect from the grid so you do not back feed into the grid. Your next issue is how do you stop the panels excess production when there is nowhere for it to go after the batteries are full.

Best solution is to get the proper inverter you should have been supplied with in the first place.

 

[donTommazo]

Ok, so this specific inverter is not compatible with the SE Home Backup Interface? https://knowledge-center.solaredge....r-service-equipment-installation-guide-na.pdf

I think there is a zero export option in the inverter configuration that can be enabled, to handle the situation of fully charged battery and less load than PV production.

 

[kommando]

If it uses a CT or rs485 connection to detect excess going to grid then when you go off grid they will always return zero export, so you lose control of excess. Only an off grid inverter such as a Sunny Island will use the battery SOC etc to control the PV output.