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Coernel82 / smartCharge4evcc

A smart charging solution addon for evcc for electric vehicles that optimizes charging schedules based on solar forecasts, weather, electricity prices, and home energy consumption.
MIT License
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a futuristic image of ev and solar panels

🚨 Disclaimer

Warning: This project is in alpha status. Expect inconsistencies in the code and naming conventions, bugs and missing docstrings. I am a hobby programmer Use at your own risk! There are inconsistensies in the naming conventions of the variables a mix of German and English. Also this code was created with the help of AI and therefore should not be used for AI traning. ⚠️

📋 Table of Contents

SmartCharge 🚗⚡

Welcome to SmartCharge, a smart charging solution for electric vehicles (EVs) that integrates multiple load points and home battery systems. This program optimizes your EV charging schedule based on solar production forecasts, weather conditions, electricity prices, and home energy consumption. 🌞🌧️💡

What this program does in some short sentences:

Using evcc's api it sets up your car trips (using a schedule) and loads the car to the minimum amount possible using the cheapest energy price possible taking into consideration future charges from PV, energy consumption of the car considering the trip lenght and the temperatures. PV charge is estimated with solcast and added to the EV. Remaining energy is used to "cache" this in the home battery. Also the energy consumption of the house is estimated by multiple factors. This energy is precharged into the battery if this is economically resonable - of course at cheapest cost possible.

Prospect

Include heatpump to preheat the house (so that the heatpump can be blocked when energy is expensive). This is different to the two implemented logics:

Participation

I highly depend on your participation now. Before creating pull requests please open an issue and let me assign the issue to you to make sure that not multiple people are working on the same function. There is a lot to do:

🌟 Features

Prerequisites

🛠️ Installation

If these instructions say sudo do so. If not, do not! Follow these steps to set up SmartCharge on your system:

1. Clone the Repository

git clone https://github.com/Coernel82/smartCharge4evcc.git
cd smartCharge4evcc

To update to new versions: git pull origin main

2. Set Up a Virtual Environment on Debian based Systems (Raspberry Pi!)

It's recommended to use a Python virtual environment to manage dependencies:

python3 -m venv venv
source venv/bin/activate

To deactivate / leave the virtual environment simply use deactivate

3. Install Dependencies

pip install -r requirements.txt

4. Configure Settings

🚀 Usage

Running SmartCharge Manually for testing

Activate your virtual environment and run the smartCharge.py script:

source venv/bin/activate 
python smartCharge.py

Running SmartCharge Hourly with Cron - this is what you need to do!

To run SmartCharge automatically every hour (you must run it every hour, not every 30 minutes, not every two hours), you can use a cron job. We'll create a bash script to ensure the virtual environment is activated when the script runs.

Note: You may run it every 10 minutes or so - you are welcome to test it and open an issue. There might be finder resolutions for weather and other data available. However at the moment running more often than once an hour only might be making sense in case of cheap home battery charging to prevent charging more than needed.

1. Create a Bash Script and make it executable

cat <<EOF > run_smartcharge.sh
#!/bin/bash
source /home/evcc/venv/bin/activate
python /home/evcc/smartCharge4evcc/backend/smartCharge.py
deactivate
EOF
chmod +x run_smartcharge.sh

This will create your bashfile without opening nano or any other editor.

2. Edit Crontab

Run crontab -e and add the following line to schedule the script hourly:

0 * * * * /home/evcc/smartCharge4evcc/run_smartcharge.sh >> /home/evcc/SmartCharge4evcc/smartcharge.log 2>&1

This runs the script at the top of every hour and logs output to smartcharge.log. Delete >> /home/evcc/smartCharge4evcc/smartcharge.log 2>&1 if you don't need the log any more.

🧐 How It Works

SmartCharge intelligently schedules your EV charging by considering several factors:

  1. Get many pieces of information from APIs 💻
    1. energy forcast from Solcast
    2. weather forcast from Openweather
    3. settings from evcc
  2. Calculate the energy consumption of your house in hourly increments
    1. using the value of the energy certificate of the house the energy consumption is calculated: x kWh / ΔK / m² / year. Break it down to an hour /365/24
    2. apply a correction factor: heating energy comes for free through your windows when the sun is shining. I estimate the energy by a correction factor: Normalize the prognosed yield of the pv by dividing through the kWP value of your pv. So the incoming radiation through the windows is somehow proportional to your PV yield. In another function the real energy used for heating and the calculated are compared and the correction factor gets adapted to make this prognosis more precise. For this I write the real and the calculated values to InfluxDB
  3. Substract baseload and heating energy:
    1. the baseload also comes from InfluxDB after it has run for some weeks. It is calculated over 4 weeks per day of the weeks and in hourly increments. So for every hour (Monday1 + Monday2 + Monday3 + Monday4) / 4 = baseload
    2. we have a value containing the remaining energy per hour
  4. Calculate energy needed for ev
    1. we have trip data in a json for recurring and non recurring trips.
    2. (delete old non recurring trips takes place somewhere in the program as well)
    3. we have a total degradated battery capacity which we calculate by age
      1. TODO: change this to degradation by mileage (we can get this from evcc, lesser config, more precise)
    4. get weather data for departure and return
    5. calculate energy consumption for return and departure trip and take into consideration departure and return temperature (complicated gauss formula derived from a graph - link to graph in source code)
  5. "load" energy to the ev with the remaining pv energy (i.e. reserve this for the vehicle)
  6. Calculate loading plan for ev
    1. the energy which can not be loaded till departure by solar energy has to be charged at cheapest cost:
      1. calculate the charging time at the loadpoint for this amount of energy amount / speed = time
      2. filter energy prices from now till departure
      3. sort energy prices from low to high
      4. iterate through them till time (in hours) = number of iteration. Return the price at that hour and post it to evcc
  7. Store remaining energy in home battery (= reserve it)
  8. Now we have a thorough energy profile which also has energy deficits for the home battery but also might have grid feedin (what we cannot do anything about as we have used the energy to the maximum possible)
  9. Calculate charging costs of home battery
    1. consider efficiency: charging cost = charing costs * (1/efficiency)
    2. consider wear and tear: break down purchase price to Wh for battery and inverter: charging cost = charging cost + wear and tear
  10. Charge battery when charging and using charged energy is still cheaper then grid energy
    1. for every hour compare: how much energy is needed?
    2. is charging beforehand (with losses, see above) cheaper:
    3. sum up the energy need for all the times where charging beforehand is cheaper
    4. calculate charging time amount / speed = time
    5. iterate as above with the loading plan for the ev
    6. set cheapest price via evcc api
    7. this can charge a bit more than needed as evcc does not support a "stop soc"

Components Breakdown

🤝 Contributing

Contributions are welcome! Please fork the repository and create a pull request. For major changes, please open an issue first to discuss what you would like to change. 🛠️

📄 License

MIT

Enjoy smart charging! If you encounter any issues or have suggestions, feel free to open an issue on GitHub. 😊