WARNING: Nest Thermostat "Seasonal Savings" May Actually Be Wasting Energy & Increasing Your Bill!

[SWLinPHX]

There have been several complaints online and in this forum from those who either do not appreciate or who are unable to deactivate the "Seasonal Savings" feature.  However this post reveals a more specific issue with serious consequences I have discovered and reported to my power company after speaking with a Google Nest Thermostat rep by phone.

I live in Phoenix where it is regularly above 110º or even 115º in the summer and own several Nest 2020 Thermostats purchased and installed by myself in ten rental properties of mine and in my own home personally over two years ago in 2021.  Ever since then I have been enrolled in my power company's Rush Hour program and also make use of other savings features such as Away/Economy mode with regard to presence sensing and cell phone tracking to save energy and money.  This helps when our rentals rent at our lowest rates in the off-season summer yet those traveling from cooler climates often over-compensate by trying to recreate a meat locker environment, running it very cold and leaving it that way even when away for a while or with windows and doors open.  Therefore, last month when my thermostats for the first time displayed a message on the main screen asking if I wanted to enable Seasonal Savings I opted in and enabled the feature to maximize savings.

This is a feature apparently introduced by Google in 2021 originally in select markets but only started showing up as an option on my two-year-old Nest thermostats (and perhaps the entire Phoenix metro area) a few weeks ago (July 2023) in the Google Nest software.  It is called Seasonal Savings and may also occur during the winter too when enabled.  It presented itself as a new option on the main screen to enable or disable.  It explains it will adjust your scheduled temperature by a fraction of a degree and help optimize your scheduled temps so I enabled it to maximize savings in addition to Rush Hour program, Eco mode, etc.

To clarify, Seasonal Savings has nothing to do with the power company's Rush Hour program or the pre-cooling period before the scheduled rush hour where the temperature is raised to save energy.  In fact, this new feature is not controlled by power companies.  Instead, it is a software feature gradually implemented by Google over several months in different regions whose job is described as to alter your set scheduled temperatures by a fraction of a degree here and there to maximize savings while preserving comfort.  Sounds great, right?

What they don’t tell you however is that even if you have no weekly programmed schedules (obviously we don’t since sometimes our properties are empty and even when occupied short-term renters will have different schedules and needs) this new feature will secretly create and implement schedules for you.  What’s more, these new schedules it creates override the presence sensing feature (sensor at thermostat) and cell phone tracking so that even if no one is home, it will cool (or heat) according to the new schedule it provides.  One of my units was empty and after enabling this new feature it started keeping it cool at 75º all day in the intense Phoenix summer heat even though no one was in there for days.  Before enabled it would sense this and thus go into my chosen "Economy Mode" setting (you can specify three settings in Nest:  Comfort, Sleep and Economy).  We have Economy set to 82º when occupied (people gone temporarily throughout the day) and anywhere from 85º to 89º when no one is renting, depending on how long it is vacant.  Notably, two of my thermostats which I did not have direct access to at the time in order to activate it did not have these new schedules created and therefore were spared this issue.

Again, without notifying users of this issue, this feature unwittingly overrides their economy and presence-sensing features and runs around the Comfort level regardless if no one is there four hours or days or weeks.  This is the exact opposite of savings!  The only solution is to both opt out/terminate the Seasonal Savings feature (or to decline it in the first place) and then also go thru all seven days of the week and delete the two schedules it creates per day (so with ten thermostats that is 140 schedules I needed to delete in addition to deactivating Seasonal Savings).  Only then did my thermostats return to normal operation, reverting to the set Eco Mode when a unit was vacant for any length of time.

I suggested that my power company reach out to Google and have them either correct this issue or at the very least warn customers that a schedule will be auto-generated that overrides presence-sensing and economy settings, causing any unoccupied residence (short-term rental or family on vacation) to run the AC or heat all throughout these newly created schedules.  If a home is always occupied it may not be as big of an issue, but as soon as it is vacated for a few hours, days, weeks or months this causes huge energy waste and of course increased bills.   Frankly, I am astonished that no one at Google Nest knew about this (at least the ones I talked to did not) and that the engineers designed it to work this way and not to inform customers that it creates schedules and will override their energy savings features when no one is home.

[CoolingWizard]

There is no real need for “Rush Hour” or Sessional Savings.  Frankly, the Nest Thermostat has had the software feature to save energy, provided, the homeowner/tenant desires to. Face it, the US Department of Energy has defined energy savings for HVAC equipment and the default cooling along with heating settings that every programable/smart thermostat manufacturer are required to implement.  It is simple, set your home and away temperature a couple of degrees higher and save some money.  

Most consumer do not understand what the “rush hour” feature is. Simply put, this is a feature the power company has requested. Again, by DOE regulations, a power company must at any given time, be able to produce the maximum energy the system has peak produce the prior 12 months.  That means in the winter, they must be producing the same amount of energy they had to peak produce during summer for example.  For this reason they created “rush hour” system to allow the energy company to turn off high energy usage during the peak hours between 4pm and 9pm. By doing this they lower the peak power demand which saves the power company operating money in the off season. 
They tried to educate consumers, for the last 15 years, to do this on their own, however, most consumers choose comfort over money savings. I too live in the desert; the bottom of the lower Colorado Desert region like yourself where the dog days of August temperatures reach 120°F. 

AC Cooling Wizard

[SWLinPHX]

Yes, I make good use of the Away feature with Eco setting.  But I agreed to the Rush Hour program when they gave me all my Nest thermostats virtually free (just $9 shipping cost each) and want to do my part as the desert Southwest is in crisis mode with increasing temps and a drying Colorado River.  The Rush Hour program allows them to smooth it out so not everyone has it cranked at the same hottest part of the day burdening the system and possibly causing more extreme issues and outages.

But my post isn't just a note about savings.  It is a feature Nest implemented that is extremely flawed and comes without warning that it may have the exact opposite effect:  costing more money and wasting energy due to the issues I described above.