PowerGuru Node

ESP8266 based application for reading energy meters, sensors and controlling switches based on price, energy forecast and grid (consumption and production) information. See main project project PowerGuru Server

Interfaces

Energy meters

Shelly 3EM energy meter

Reads consumed and sold energy information from the meter (http query) and calculates net net consumption for current period.

Inverter with Fronius Solar API

Solar power production values energy (cumulated) and current power can be fetched from Fronius inverter. Tested with FRONIUS Eco 27.0-3-S .

Inverter with SMA Modbus TCP

Solar power production values energy (cumulated) and current power can be fetched from SMA Inverter via Modbus TCP interface. Tested with STP8.0-3AV-40 (Sunny Tripower 8.0).

PowerGuru Server

All day-ahead (spot) electricity price data and energy production forecasts are preprocessed by a PowerGuru Server instance. Powergutu Node gets state info (e.g "now spot price is low") from a PowerGuru Server service (http query).

DS18B20 temperature sensor

Currently one sensor is supported per a PowerGuru Node device.

GPIO controlled switches

One or more low voltage switches which can control grid voltage switches. Leave grid voltage installation to a certified professinal.

Current status

The software is under development (alfa testing)

Hardware Configuration

Example 2 channel configuration with ESP8266 based 2 channel relay module ja temperature sensor. With this configuration you can control for example 12VDC (or 24VDC) controlled AC relays or a water-based underfloor heating system (select between pre-programmed temerature levels). Waterproof temperature sensor can be attached to hot water pipeline or a water boiler, to sensor water temperature.

Required modules/parts:

ESP8266 microcontroller with relays

• ESP8266 (ESP-12F) Relay Module Aliexpress
• USB to TTL converter for initial setup (this board does not have an USB connector), e.g.,
• female-female Dupont Dupont jumper lines for TTL connector, 4 pcs, e.g.
• Optional DS3231 real time clock (RTC). Without RTC clock sync from internet or manual clock sync is needed after restart (including power breaks).

Temperature sensor DS18B20

• DS18B20 waterproof temperature sensor, Aliexpress
• ≅ 5kΩ resistor for 1-wire pull-up resistor, between data and voltage connector
• Electric cables (3 wire) for connecting the sensor

12V wiring:

• 12V power supply, supplying power to ESP8266 module and pulling external relays

• Electric wires for 12V connection (two color, e.g. red and black recommended)

• female and male connecters for 12V, optional Aliexpress

• Screw terminal blocks, optional Aliexpress

Tools:

• Soldering iron, soldering tin
• Tin suction gun (optional) for desoldering

Thanks

- https://github.com/me-no-dev/ESPAsyncWebServer  - Control UI web server
- https://github.com/ayushsharma82/ElegantOTA  - OTA update
- https://arduinojson.org/ - Processing web API results