I thought that some might find it useful if I were to summarise some of my energy related automations in case they might be of interest to others. Some of these are very basic and obvious, some slightly less so.
As background, I am in the UK: I have an air to water heat pump in my house (for space heating and domestic hot water), a separate air to air heat pump in my shed, solar panels and an electricity tariff (Octopus Agile) whose price fluctuates every half hour based on the wholesale price and where the price sometimes goes negative. I live alone. My domestic hot water cylinder is large for single occupancy, so I can heat the cylinder once a day and it will give enough energy for the whole day’s usage.
My automations are as follows.
- Using the Octopus and Target Rate integrations, the heat pump heating the water is set to run only in the two hours a day with the lowest energy price
- During sunnier times (i.e., when the next day’s solar forecast is >10kWh), the Target Rate integration only chooses times when the sun is likely to be shining to heat the water.
- When HA detects that my mobile telephone leaves the area of my house, the space heating is turned off, to be turned back on again when I enter a radius of about 2 miles from my house (to give the heat pump enough time to reheat the house in winter).
- The heat pump in my shed turns itself off if my motion sensor there detects no occupancy for more than a certain period of time.
- I have disabled the heat pump’s built-in legionella protection and instead use an HA automation to do this, only triggering a higher temperature if it has not recorded a higher temperature being reached for a specified period of time.
- When electricity prices go negative, the water is heated to its maximum temperature of 70C; with my shower mixer valve, this generally means that the water heating does not need to be run the next day.
- When electricity prices are very low (<£0.07/kWh), the water is heated to 60C instead of the usual 50C (which is enough to reset the legionella protection cycle and often is enough so that the water heating does not need running the next day.
- When the outside temperature goes above 24C, the minimum heat at which the space heating comes on is reduced to 18C, resetting to the default 20C when the outside temperature goes below 16C - this is intended to stop spurious triggering of the heating on summer nights when there is plenty of warmth inside the house
- I have individual thermostatic radiator valves in each room - these are set on a timed sequence not to heat unless they are likely to be needed, but can be overridden by various automations; but the ones in the rooms that are intended to be heated to full comfort temperature are always set a degree or two above the heat pump’s desired temperature setting, to make sure that the temperature in those rooms is limited by the heat pump’s flow temperature rather than the TRV cycling, which is more efficient
- Whenever I go to my shed, I activate a button on my HA dashboard that automatically turns down the house heating and turns on the shed heat pump.
- The heat pump is set to a lower target temperature overnight (17.5C instead of 20C), and it is triggered to increase to the higher temperature by an automation linked to the alarm on my mobile telephone that I use to wake (and by default increases at 0930h) so that I do not heat the house in the morning earlier than necessary
- When electricity prices go negative, a space heater in the conservatory is turned on if the temperature in the conservatory should be (and remain) <30C
- When electricity prices exceed £0.25/kWh, the charger for my tablet computer turns off until they should go below that price.
- The radiator TRV in the parlour (the front room, used only for receiving guests) is set to maintain only 7C unless I press a button on my dashboard indicating that there are guests in the house, which then reconfigures which rooms are heated to what temperatures.
- Because energy prices are typically much higher in the 1600h - 1900h period than in the 1300h - 1600h period, I increase the target temperature in the house by 1.5C in the 1500h - 1600h period, and then reduce it to 19C in the 1600h - 1900h period so that less space heating power is required in the more expensive period.
- Whenever my diary (connected to HA by a calender integration) states that I am staying in an hotel or similar, my away mode is automatically set, meaning that the domestic hot water heater is not activated at all - until the day before the period marked by the diary as an hotel stay or similar ends.
- Whenever the electricity price goes negative, a lamp in my bedroom turns on with a green colour to remind me to use as much electricity as possible; it turns off again when the price increases above 0.
I am currently in the process of installing more energy monitoring and am also considering the following further automations.
- With the assistance of a Shelly, which I have yet to have installed, turn on the back up immersion heater whenever the electricity price goes negative
- Integrate my window sensors with my thermostatic radiator valves so that I am not heating a room where I have the windows open.
I do not currently have any battery storage, and am considering whether this would be worthwhile or not.