EmonPi plus smart plugs to make better use of Solar PV - using smart plugs and far infrared heating panels

Hello all possible

I’ve had solar for 6 years, and an EV for 5 (using MyEnergi Zappi charger).

I saw OpenEnergyMonitor a while back, and would really like to get something set up as I could definitely make better use of the generated power. As we drift into the colder months - whilst I know there’s less power - using any ‘spare/unused’ for extra heating will be a bonus.

I think the EmonPi will hugely help me understand my usage, but what I’m curious about is if I could somehow link it up to a smart plug connected to a small/medium power far infrared heating panel(600w?), so that when there’s enough excess power it turns the heater on, then (with some kind of timer logic so it’s not silly - I don’t mind using some grid power) once the sun goes down or I’m using more electricity in the house it turns the heater off again - all automatically?

Obviously I’d want the option to disable such a system, or perhaps just unplug the device etc…

Hopefully that makes sense - any advice / signposts to existing posts would be hugely appreciated please

Thanks very much

Welcome, Sky, to the OEM forum.

But for the fact that you want to use your(?) emonPi, that sounds exactly like an application for Robin Emley’s Mk2PVRouter - and that will sop up exactly the surplus energy that would otherwise be exported (assuming the heater can use it), and will never need manual intervention. In effect, the router (diverter) will switch the heater just like a thermostat, but a lot more rapidly as it tries to balance the nett energy flow at zero. I don’t think it will work with a smart plug, however he does offer a remote load option using a radio link, which amounts to the same thing. There’s a full description of the operating principle in the ‘Learn’ section here.

Alternatively, you can use the Wi-Fi relay in conjunction with your emonPi, but this will need rather more setting up (which is outside my area of expertise, so I personally can’t help you there). From what you write, I think this would operate much closer to the way you envisage, but I can’t offer a guess as to how accurately it might be able to balance the surplus energy. With genuine relay contacts handling the switching, even though you’ll be switching only 600 W, it will of necessity switch a lot less frequently than the triac of the Mk2PVRouter. So depending on your meter, you might or might not get charged for the import that is balanced by export when the surplus is below the rating of your heater.

Thank you @Robert.Wall for taking the time to type such a comprehensive response

I’d seen the Mk2PVRouter but much of it went over my head… Sounds like I need to give it another shot

Thanks again, really appreciate it