Grid-Enabled Water Heaters

Designed for energy management

Grid-enabled water heaters (GEWHs) are standard electric water heating units 75 gallons or larger. In accordance with Department of Energy rules for resistance electric water heaters, they have built-in software or hardware that limits their performance by 50% unless they’re installed on a utility energy-management program such as our off-peak program that offers discounted rates or a monthly bill credit in exchange for partnering with us to help manage the electric system.

The benefits of grid-enabled water heaters

These types of water heaters not only recognize the importance of energy-control programs, but also help keep your electricity costs low. Even better, GEWHs are eligible for rebates of up to $300.

How grid-enabled water heaters work

GEWHs are designed to meet the Department of Energy's efficiency requirements that went into effect in April 2015. They're more than 90% efficient with efficiency varying by tank size. (Look for the uniform efficiency factor [UEF] rating when selecting a new water heater.) 

A qualified contractor must install this type of water heater and will activate the unit’s full capacity once it's connected to our energy control system. We use energy control to manage the electric system during peak demand, maintenance, and emergency events.

  • GEWHs require an activation key (software code or mechanical key) to be used during installation to enable the unit to operate at its full design capacity.
  • The law intends that GEWHs be activated only when installed as part of a utility thermal storage or demand response program.
  • Without activation the GEWH will provide 50% or less of its rated first hour delivery of hot water. This is accomplished by one element remaining off.
  • Please note: Otter Tail Power Company representatives cannot unlock water heaters. Your installer will need to make arrangements for unlocking your unit. The unlocking process allows the second element in the water heater to operate as needed.