Initial version of solar-power-router-for-water-heater.js

[Tof973]

This script use a Shelly PRO EM 50 in standalone mode to act as an "Energy Router" usefull to redirect solar overproduction to a Water Heater. There is no need for any Home Assitant nor other shelly device .
Mainly made for France but can be easily adapt.

Working:
Configuration of the parameters in CONFIG header object.
The two clamp meters should be connected in the following way:

• EM1(0) = A on the house grid main phase cable
• EM1(1) = B on the heater phase cable
• The Shelly Pro EM 2A switch should be connected to the water heater managment switch in place of the Linky.

During specific day period, the shelly is looking for EM1 every 10 minutes (the last 1 minute data) and if there is enought overproduction (energy returning to provider) , it turns ON the water Heater.

A minimal period of Time wre the Heater in ON should be configured (2 hours by default).
When the cumulation of time ON during the day was not enough (because of bad water, etc), the missing Time is compensate by putting the heater ON during he night in the "Lower prices period" .

This script is particularrly usefull for solara autoconsum , when the overproduction is not sold out back to provider , and it work also with a solar system with batteries (you can set up a night time range not cosuming batteries) .