The UK is currently experiencing some prolonged windy weather and my all-renewable energy provider offers dynamic pricing. That means cheap energy and even negative-cost energy. This is where my HA instance shines and saves me a fortune on my power bill. Thanks again to the HA devs for this incredible project.
For the curious, I'm using bottlecapdave's excellent Home Assistant Octopus Energy integration via HACS.
I'll be taking advantage of the negative cost energy to charge my car. How have you got HA set up to take advantage? Is it automating certain appliances running when the rate is lowest?
Yup! No EV here, sadly, and I live in a flat but I've got storage heaters and a big hot water tank. I've got an incredibly janky template sensor that works out how many hours of heating I need for each room based on the weather forecast and an automation that activates the heaters for that many hours a day at the cheapest times. It can also turn the heating on when the price drops below a certain threshold, currently 0p.
Are there any creative energy sinks you could run when the price goes negative? I can only think of mining crypto or transcoding video or stuff like that.
Dingdingding! Correct. For the chepest two hours a day (or any time cost is negative) Home Assistant gives Portainer a kick and I sail the high seas. Whenever costs are negative I saturate my servers with BOINC CPU-heavy workloads like ClimatePrediction, Rosetta@Home, LHC@Home and World Community Grid.
Flip side of heating could be to lower the temperature of freezers. If the energy is free anyways.
In my old place I actually did this: replacing my fridge and freezer's thermostats with an ESP Home controlled relay and thermometer. This place has a fancy integrated unit that I don't want to play with too much.
One of those giaaant resistors and a significantly higher current service from the utility!!
Flip side of heating could be to lower the temperature of freezers. If the energy is free anyways.
That sounds good! I can see how that would save a lot of money on the bills. I especially like that you've got a "janky" template sensor haha. HA is so good for it's openness and letting you bodge things together which have no right to work but do so all the same!
What's your power bill look like monthly with this?
I'm currently paying £50/mo and that's with credit building up on my account. My initial investment in HA has paid for itself many time over.