Calculate Solar surplus

Hi everyone,

I have 18 * 370W solar panels and 2 mpp solar 5048MG inverters in parallel. I don’t send back to the grid solar surplus.
I can follow my production with a raspberry on which is installed influxdb and grafana (daromer iso).
So I know if I’m consuming electricity from solar or grid but when my house doesn’t use energy I can’t know what would be production and so the surplus ? How to calculate it?

Bonjour Benoir, welcome to the OEM forum.

If you are connected to the grid, why do you not send energy back to the grid? Here in the UK, everyone is encouraged to export their spare energy. For you, is it because of the way that your inverters are configured? Or is it a law of France or your energy supplier who says that you must not send energy into the grid?

If your inverters are not permitted to export energy, I do not think it is possible to calculate what your production might be, because you need to know how much current your panels could produce given the amount of light falling on them. The inverters might know that, but they might not make that information available to you.

The only alternative that I can think of is to install a small panel, whose only purpose is to measure the amount of light available and therefore estimate what your 18 panels might generate.

Bonjour Robert,

Because my inverter can’t do it.
But I found a solution, shortly I will connect batteries to stock my surplus so what will charge my batteries will be my surplus :slight_smile:

That is good for some surplus until it becomes full, then what?

Bottom line, storage would have to be larger than any production possible.

Heated water in large storage can take some additional diverted PV production after the battery becomes full. And calculated in addition to battery.