I have no idea if it'll meet your requirements or not, but have you looked at something like this GE direct-wire smart switch? https://www.amazon.com/dp/B00YTCZZF0
I have two use cases for this specific switch that I haven't acted on yet:
* schedule my non-smart EVSE to charge our car when power is cheaper at night
* monitor (but not control) the energy usage of our electric hot water heater. It's the second biggest electricity user in the house but I have to infer how much power it's using based on the other separately metered components.
Cost is the thing holding me back. Will it have positive ROI in a reasonable time for our PHEV minivan that only has a 30KWh battery? Seems somewhat unlikely. Would monitoring the power usage of the hot water heater have positive ROI ever? Also seems unlikely.
