README.md

Energy Watcher

A python script that fetches tomorrow's price data from the Octopus Agile tariff and looks for the cheapest 90-minute window for charging a battery.

It can also track the solar forecast for your installation and give you a summary of the data for the last 24 hours.

Installation

Clone this repo onto your system and install the requirements with pip install -r requirements.txt

Find the values for the required environment variables:

• OCTOPUS_TOKEN - this is your Octopus API token, found on the Octopus Developer Dashboard.
• ACCOUNT_NUMBER - your electricity meterpoint MPAN, also found on the Octopus Developer Dashboard.
• MASTO_TOKEN - your Mastodon client access token. Follow the official documentation for help setting that up.
• BOT_HOME - the base URL for the Mastodon account that will be posting. This defaults to https://botsin.space.
• SEND_TOOTS - in order for your toots to be sent this MUST be set to yes. This is to avoid sending toots when debugging.
• SEND_TOOT_TO - who you want to receive the toot.

Next create a crontab entry to schedule the running of the script, this also sets the required environment variables that the script needs:

OCTOPUS_TOKEN=api-token
ACCOUNT_NUMBER=octopus-account-number
MASTO_TOKEN=masto-access-token
BOT_HOME=https://botsin.space
SEND_TOOTS=yes
SEND_TOOT_TO=@recipient@host.com
0 20 * * * /usr/bin/python /path/to/repo/main.py 2>&1

Optional solar forecast reporting

You need to locate the values for the following environment variables: LAT, LNG, DEC, AZ, KWP. These values and how to determine them are amply described on the Forecast.Solar web-site. The API updates every 15 minutes, so there is no point in querying more frequently than that, but you can definitely pick larger intervals if it suits you.

NOTE: This functionality uses the public Forecast.Solar API and will count against your quota if you use Home Assistant or some other service that uses this API.

LAT=your-lat
LNG=your-lng
DEC=your-declination
AZ=your-azimuth
KWP=your-kwp
*/15 * * * * /usr/bin/python /path/to/repo/collector.py 2>&1

Profit!

Customisation

The template for the message is stored in templates/message.txt.tmpl and can be customised as you see fit.