Shout out to Home Assistant!

I have a docker instance of it running on an Ubuntu server at home, and I bougth a few pre-flashed Tasmota electricity meter plugs from Delock. I added another docker container for mosquitto (MQTT) which reads the plugs and integrates into HA. This way I learnt my NAS eats as much electricity a day, as does playing Horizon Zero Dawn on my PC for an hour. Ikea Smart lights on half the brighness are basically non-consuming, and the router is best kept shut down when we're not home for a week or two.

In the end, small household appliances don't make as big a difference, as letting your car charge with solar when electricity is cheap, and reducing charge speed when electricity is expensive (which is also doable with HA). There were great threads in HN about how you can even save energy by heating up or cooling down your house in advance with cheap electricity during the day when demand is low, and turn down the heat/ac in the night when demand is high, thus storing energy in the form of heat. But as a junior programmer with a wife in an already expensive apartment, small savings add up. We realized that running the washing machine less often but fully loaded, and with the lowest temperature water, saves us approximately the cost of Netflix. Few people know it's even fine to wash clothes with cold water.

Ultimately though, our apartment is pretty well insulated, and I would do all the home automation that I have just for the fun of learning. I definitely spent more money (and time) on the server and smart things than what they save us in our bills. Although I hope to apply my knowledge soon at my parents' house, where there's a lot more potential in energy savings.