Electric Thermal Storage (ETS)

Introduction

There are a variety of technologies for heating a residential home. Such choices include natural gas, propane, electric, and wood. Operating costs for heating a home tend to vary from one year to the next as fuels are market driven. Resources are becoming less accessible every year. Today, there is great interest for energy efficiency, conservation, and the safeguarding of our environment. Developing new sources of energy is important and such examples include solar, wind, and geothermal energy. However, by using more efficient and economical storage devices we can use our existing resources more sensibly. Fortunately, there are more advanced options available today utilizing closed-loop control systems. A closed-loop control system is defined as “measuring the difference between the actual value of the controlled variable and the desired variable and uses the difference to drive the actual value toward the desired value.” An example of a closed-loop control system is Electric Thermal Storage (ETS).

What is Electric Thermal Storage (ETS)?

Electric Thermal Storage (ETS) heat is a quiet, odorless, affordable technology utilizing electricity. ETS pertains to the development of transforming electricity to thermal energy and saving it as heat. ETS has been around for decades and is commonly used in Europe and Canada. However, this type of storage is not feasible in areas with a lack of electrical service or high-priced electricity. ETS is effective where low-priced off-peak power capacity is offered. Heat can be stored in a few types of storage materials. The most common type of storage material is high-density ceramic bricks with an electrical heating element at its core. The bricks are encased in insulat...

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...charging, some of the heat is released into the room to provide immediate comfort. The rest of the heat is stored in the bricks until its’ needed.

During on-peak hours, the heating elements are shut off. Insulation around the core helps the bricks retain the stored heat. After the ETS unit has been charged, fans inside the heater move air around the bricks. The air is warmed to 180 to 200 degrees and returned to the room. Since the process is controlled by a wall thermostat, one can get as much or as little of the heat as one wants.

The ceramic bricks are made out of a high-density iron oxide that surrounds the elements to absorb heat. The high-density compound accomplishes two things. First, it holds more heat for a longer period of time and second, it requires less space. See Figure 1 for a pictorial representation of an Electric Thermal Storage unit.

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