Grid power cut, lost data

Hi all

Yesterday we had a power cut from 11am to 10pm (annoying that we had a near full battery for a lot of this time but couldn't use a single watt of it, grrrr! But that isn't the reason for this post). The battery continued to charge (looking at the lights on the side) but once power was restored and the inverter connected to the WiFi, the data from that period was lost. I'm guessing the inverter doesn't keep this historically which is a bit annoying. Is this the case? I'm really starting to be against this cloud set-up, there are more draw backs than advantages to the end user. A hybrid system would be much better with local control and data capture being the primary with periodic and historical updates to the cloud as the secondary.

Local control is the answer to a very large number of questions.

You do know that you have an EPS built into your inverter? A proper electrician can wire it up for the next power failure.

anabanet Is that where I can have one 13A socket to use during a power cut?

The data from the inverter snapshots is purely that - a snapshot.
The cloud part does most of the heavy lifting storing all the figures in the portal / turning it into graphs.

The inverter doesn't store this up if it can't connect, nor does it record anything other than cumulative figures internally. i.e even in local control mode you can't query the inverter for past power output data from days gone by.

chris_p That is the very easiest and cheapest option - almost like having an extension cord dangling out the inverter. You can also run a separate Consumer Unit, and have a few circuits dedicated ( such as lights, TV and a special kitchen plug ) This makes it quite a robust and permanent solution, more costly, but very effective. - Finally you can go mental and have whole house switching but imo - that is a bridge too far.

hoggy Very disappointing that they didn't think to include at least a tiny bit of storage for this eventuality. WiFi drops can easily occur, power cuts etc.

anabanet Hmmm might be worth considering at least lights and the odd socket for things like fridge/freezer. Guessing the demand has to be kept under 2.5kWh?

It’s a specialist option, the installer can fit it - but generally only on request.

Some installers might ask if you want it, others might assume you know it exists and that you would ask for it to be fitted.

You’ll probably need a new earth fitting too, in order to use the EPS.

“In Island mode EPS circuits must not rely on a TNS or TN-C-S earthing system as when grid is lost earth and neutral may also be lost. A TNS or TN-C-S earthing system may be left connected when operating in island mode.”

https://kb.givenergy.cloud/article.php?id=12

chris_p no inverters I know of store any data locally.

Very few electric meters do - I know of three ranges from Schneider that do this - but the cheapest is about £400 (they go up to about £10k) most meters just send what they are currently reading when asked. Don’t ask don’t get!

My SolarEdge inverter saves data if it loses it's internet connection and uploads it when it reconnects.

judgepd interesting. That’s quite good is that!

chris_p Fridge and Freezer take care of themselves IMO. If you have a power failure, dont open the freezer, and it will last 24 hours. My power failures ( several times a year ) last 60 minutes to 3 hours.

Loosing Internet is critical - I work from home. Loosing Sky is just annoying as my recordings get interrupted. Loosing lights scares the kids. Not being able to make tea is just wrong on so many levels...

So my EPS is : Modem, Sky, Lights, Kettle. Then I am happy.

anabanet The fridge and freezer request came from my partner, we nearly lost a freezer full of stuff when it went pop last winter. I know it should be ok in a typical power cut but she wants peace of mind.

judgepd Same with the myenergi zappi / eddi, they store the data locally and send it through the optional hub when connectivity is restored.

With how impressive the GivEnergy cloud portal appeared I was really shocked to discover GivEnergy inverters don't store the data until it's confirmed to have been uploaded.

Has anyone seen official comment on this from GivEnergy? Is it something they are considering implementing?

Please could someone from GivEnergy confirm what, if any, data is not lost in the event of lack of connectivity to the GivEnergy servers?

Is it just the (five) minute interval data that's lost?

Does the inverter store daily totals for charge/discharge, generation/import/export and synchronise those when connectivity is restored?

chris_p Freeze a plastic 400ml bottle half filled with water. When frozen solid, drop a penny ontop of the ice and place in the freezer. If you have a thaw, that would affect the frozen products, the penny would have dropped so to speak.... If you want it especially sensitive, then add a little salt to the water. It requires a deeper temperature to remain frozen solid, so it 'mealts' at around -4 degrees, so you have a much earlier warning of any issue.