Batteries:Degrees of power cut protection

NoobSolar

Which batteries will charge from my panels during a power cut? I have a solaredge HD Wave inverter. Also which battery will be capable of running a circuit / some outlets in a power cut?

Reed_Richards

I don't know the answer but I do know that you need to ensure that your inverter will continue to run via power from the battery and or the panels.  If the inverter goes off it cannot control the panels or the battery so, I believe, cannot be turned back on again without mains power.   

gefnew

If a power cut occurs then the inverter shuts down to isolate from grid to protect the engineers working on the fault .You would have to have some form of islanding on your system.

NoobSolar

Is there a cheap - ish way to do that? I am hoping one day to get a givenergy or pylontech battery.

QrizB

NoobSolar said:

Is there a cheap - ish way to do that? I am hoping one day to get a givenergy or pylontech battery.

Yes, you could split your consumer unit into "essential" and "non-essential" circuits and then use a contactor to isolate the essential circuits from the grid when the power fails.

There's a diagram of how to do this in my Sofar's installation manual, and I would expect other battery inverters to include similar information. Your installer should be trained in how to do it.

Martyn1981

If you're interested there's a vid here from Fully Charged where Bobby has the Tesla Gateway added to his Powerwalls. This acts as a giant switch connecting or disconnecting the house from the Grid, thereby allowing the batteries and PV to operate legally in Island mode, with no risk to any engineers working on the local network.

Obviously the Tesla set up is not at all cheap.

Several years ago a Vid channel I watch 'Tesla Time News' had a powercut whilst they were filming. A tree actually fell taking out their powerlines, and there was just a flicker, the filming didn't miss anything, whilst the presenters were shocked having heard the crash outside. That was in the US, again with Powerwalls (4 PW II's I think) and the Gateway.

Tesla Powerwall: how quickly can it respond to a power cut? | FULLY CHARGED for clean energy & EVs

gefnew

Hi NoobSolar.
This is a quick browse on the net.
Victron Anti-islanding box 63A | Victron Energy Accessories | DIY Solar (zerohomebills.com)

QrizB

Having a bit of a Google around the subject, it seems that Enphase offers "sunlight backup" on its IQ8 microinverters, at least in the US.

Here's a pdf from their US site:
https://enphase.com/download/sunlight-backup-user-guide-homeowners

An Enphase Sunlight Backup system provides backup when the sun is shining. The system provides backup for up to 4x 240V or 8x 120V circuits. The system consists of IQ8 Series Microinverters, IQ System Controller 2, IQ Combiner 4C, 2x IQ Load Controller and other accessories as needed.
NOTE: Sunlight should only be used for the essential loads in the home. Using the solution to backup the entire home will lead to poor experience and is not supported by Enphase.

Here's a basic installation diagram; it's much as previously described, with a separate "backup loads" panel that is maintained by the IQ8 microinverters (the diagram includes Emphase's own battery storagr system):

Enphases's batteries are shown as "coming in 2022" on the Enphase UK website.

Reed_Richards

Ruddy heck, £770!?!  What I have is an Automatic Transfer Switch; these seem to cost about £60 online and that was approximately what I paid my electrician.  Mine is designated CGQ2...  But this is used in conjunction with the inverter which automatically routes the output to a different "back-up" port in the event of a grid power failure.  The ATS switches the protected circuits off the mains and to the back-up inverter output.  The lights flicker when the switchover takes effect but it's very quick.  

gefnew

That`s what happens with a quick browse of the net.

ispookie666

Interesting the Zeihl anti islanding box should come up. I looked into this when I had the victron multiplus, looking at the cost I purchased a Multiplus II. 

I made up an ATS using a few relays - the peak power for the system was 1500W including inductive load of 200W. This was to run a fish tank from two mains input to add redundancy. It worked a treat. 😜

@QrizB that Enphase system is geared towards US markets. I doubt they would even consider getting approval for these kit on this side of the Atlantic..
From what I understand, Enphase does frequency shifting to reduce inverter output power.  I do not know if the grid generated by the standalone inverter would be sufficient to restart the Enphse micro inverter.