Switch AC outlet on when on-grid solar is generating

[ctdctd]

I have a 2.5Kw Solar on-grid setup in the UK.
I also have a 24V 100Ah battery setup with an 250W AC charger which I use to power stuff at night.

At the moment, I charge the battery when the sun is out - this works well, but I tend to micromanage it and spend far too long looking at the net generation figure!

So, what I want is a controller that does something like:-
1) Is net generation > 300W?
2) If yes, switch on battery charger
3) If no, switch off battery charger
4) Wait 5 minutes or so, then go back to 1)

Nice and simple - programmable thresholds and time would be useful as would an additional switch to use with something else on really sunny days.

Not sure if this is a commercial product or if it needs to be a home brew.
Anyone done it or got any suggestions?

 

[sunshine_eggo]

The idea is to use "free solar" to run your charger?

Can it be approximated by a simple timer, i.e., can you identify a timeframe where your array usually produces 300W and then simply put the charger on a timed outlet where it only runs during the time you typically get >300W?

 

[ctdctd]

Yes - only charge when there is 'free' solar.

No, I need to measure the power being exported to the grid to allow for variable sun and variable use of power.
This can be done with a clip meter to my house AC power cables or by reading the display on my Smart Meter - however, it does not have a data export facility.

There are commercial products which are designed to use 'free' solar to power a water heater with a variable voltage but they are over complex and expensive for my requirement.

 

[solar8484]

Should be straight forward to do with emonPi (https://openenergymonitor.org/).

 

[ctdctd]

Thanks, I've decided to try DIY and have a clamp current transformer and a Wemos D1 mini coming today.