feat: add shelly script example

[hoinmic]

Add ShellyScript battery management demo with grid power balancing. Script automatically charges battery when excess grid power is available and discharges when additional power is needed.

The script can be executed directly on the Shelly device (e.g., Shelly Pro3EM).

[hoinmic]

@dav1dBoy I made an example for shelly script. What do you think?

[Spessartwald]

I made a similar thing with ESP32 & Tasmota. Took me some time to implement a PI control loop, which will achieve +/-2W grid power consumption after 30sec with the SF800Pro for slow changing loads, but fast enough to follow a switching coffee machine heater with 1,3KW and ~20sec on/off cycle to keep its temperature. The total efficiency in this case is not the best, due to a minimum cycle time of 1sec to get the power value from the smartmeter, and the settling time of the SF800Pro of approx 2sec from 0->800W. I assume that my current control loop has an efficiency of ~90% during a ´standard´ day, with cooking, washing, gardening. This means losses (feed to grid) of 0,3KWh, on a sunny day. That´s sufficient for me from cost point of view, but not from a technical point of view. It should be almost ´0´

Im very interested to see the transient behavior and total efficiency of your control loop with the Shelly. Do you have any measurements ?

[hoinmic]

Thanks for your comment. I tested the code with a “Zendure SolarFlow 2400 AC.”

In my case, I can only evaluate the results based on nighttime data, since the device is used as a supplement to a larger solar system (during the day, the Zendure SolarFlow 2400 AC is more or less just charging, and there isn't really any regulation taking place).

Normally, I achieve an autonomy of 96–98 percent at night (active devices: freezer, refrigerator, lights, dehumidifier, Wi-Fi, etc.).

To illustrate, here are the results from last night (since midnight):

[Spessartwald]

Good morning, thanks for that.
Your Shelly script matches perfectly to your SolarSystem.