Smart Water Heater Controller Study

One easy way to help build a clean energy future for our community

Smart Water Heater Controller Study 2In March 2022, Tacoma Power began a two-year study to help regional utilities find out if smart water heater controllers can help us balance energy supply and demand by providing a cushion when wind or solar don’t perform as expected. If our study is successful, we could help our region add more renewable energy without natural gas backup generation, which helps keep everyone’s electric rates low, while also reducing regional greenhouse gas emissions.

The controllers use machine learning and real-time data to keep homes comfortable. The goal is to provide hot water when needed and save energy when not needed.

Findings from the research will help accelerate beneficial, clean energy programs in our community. Participants received $40 when the controllers were installed and will receive a second $40 payment when the study ends in December 2023.

If you have questions about the study, call 253-502-8363 or send us an email at


How does the smart water heater controller work?

A controller allows your tank to operate as a battery. It shifts the time your tank uses clean energy to heat your water (when it’s more abundant and less expensive) then stores it for use later. 

The controller observes how much power goes into your water heater and which element heats the water. An algorithm uses the observations to learn your hot water needs and builds a schedule that keeps enough hot water in the tank for when you need it, and delays reheating by switching power off for brief periods of time to delay reheating until cheaper clean energy is available. If you change your behaviors don’t worry. The controller can detect those changes and will maintain your regular water temperature until it figures out your new normal. If it appears you are on track to run out of hot water, your water heater will return to normal operation.

What will I experience?

There may be occasional times when you notice a slight decrease in your water heater performance. You can fix this by turning up the hot water most of the time. If you see a big difference and are unhappy, let us know — your feedback helps us adjust to improve performance.

How will the utility ensure the privacy of  the information sent from the smart water heater controller? 

All water heaters are identified by a unit number on the smart controller. The utility is the only entity aware of your smart water heater’s unit number. All information in the cloud is encrypted. We also do not share your information and identifiable information about you is not stored in the cloud.

What am I responsible for during the study? 

You are responsible for: 

  • Scheduling your installation time with the contractor who contacts you
  • Maintaining your hot water heater
  • Keeping your contact information on your utility account current
  • Participating in brief seasonal surveys throughout the study
What happens to the controller after the study is done? 

The controller becomes your property after the study ends. We will also remotely disconnect the smart water heater controller from transmitting information, analyzing your energy use, or doing anything to your water heater. You may leave the controller installed, remove it yourself, or hire a professional to remove it.

If I leave the study early, will I still receive $80? 

You will receive $40 after the installation of your smart water heater controller. If you move to a different residence or choose to leave the study after installation, you will not receive the second $40.