Thermal Storage

Install thermal storage off-peak, get rebates

Whether you’re building or remodeling, thermal-storage systems offer an efficient option for heating your home. And when you install one on an off-peak program, you’ll enjoy even more savings with our rebate program and discounted rates that lower operating costs.

Thermal-storage systems run quietly and cleanly without combustion by-products associated with burning fossil fuel. They operate by generating and storing heat in sand or specially designed bricks during off-peak hours then use it to provide heat as needed, including during peak periods when electric service may be controlled. Thermal-storage systems can heat an entire home, a single floor, or an addition. Options include:

Although most commonly used in commercial cooling systems, thermal-storage cooling technology also is available. Residential systems have been introduced but aren't commonly used in our region. Thermal-storage cooling technology generates ice or cooled water during off-peak hours using it to cool during peak periods.

Rebate eligibility and details

We’ll rebate $40 per kilowatt of thermal-storage heating or cooling installed on a qualified off-peak rate, including our Deferred Load, Residential Demand Control, or Fixed Time of Delivery Rates when the system has adequate storage capacity to heat or cool the space during the maximum control period allowed by the rate on which it's installed.

A rebate of $500 per unit sized 9 kilowatts (kW) to 25 kW, or $20 per kW rebate for systems 26 kW or larger, is available for electric cable or panel underfloor heating applications installed on our Dual Fuel Rate. Electric cable or panel storage heating rebates are limited to new construction slab foundations.

Typical home systems are between 26 and 38 kilowatts in size. With our rebate you could save hundreds of dollars on your new system!

Rebate qualifications

  • All rebates require a minimum installation size of 9 kilowatts.
  • In combined thermal-storage/air-source heat pump systems, this rebate applies only to thermal-storage heating load. Qualified heat pump systems are rebated separately.

If you have any questions about program eligibility, contact our Idea Center or call 800-493-3299 during business hours.

Apply for your rebate

Contact your Service Representative when you're ready to install your thermal-storage system to ensure it's properly set up on an off-peak rate and available for energy control.

After installation is complete, fill out the rebate form and give it to your Service Representative or mail it, along with all required documentation, to:

Idea Center
Otter Tail Power Company
P.O. Box 496
Fergus Falls, MN 56538

Please allow 6–8 weeks for your rebate check to arrive.