09-06-2022 12:07 PM - edited 09-06-2022 09:42 PM
I am having trouble in figuring out how this thermostat saves me money.
I had to turn off the home-away assist because it was using more energy on the days I was out of the house by a wide margin. On August 9th and 11th, I was home all day and used 10 kWh. On the 10th I was out of the house from 11:30am to about 7:30pm. Which means I was out of the house for 8 hours, not a small amount of time. (Note: The first day, Saturday August 6th was another day I left and Home/Away Assist was activated)
I have solar panels and you can see the negative kWh during midday but at night you can see that I am pulling from the grid. On the 9th and 11th you can see that at no hour does the energy spike above 3 kWh. On the 10th you can see that it balloons to 10 kWh at 8pm and 9pm when it's trying to catch up from the A/C being in eco mode all day (don't be thrown off by the scale, the 10th has a much larger scale so the other hours look smaller).
I don't have the Nest history on hand because it was last month and I can't see it anymore. On there it looked like the 10th used less energy because it was on for less hours, but in actuality it just used a bunch of energy in the span of 2-3 hours compared to occasionally over several hours on the 9th and 11th.
How do I actually use this thermostat to save me money? I normally have the thermostat set to ~70F (anywhere from 68-72F depending on humidity and other factors). I would set the away temperature lower when away so it's not a big gap, but the ECO mode won't go lower than 76F. I work from home most days, so there's no way I can predict which days and times I'll be out of the house.