electric thermal storage systems and solutions

Electricity is much more expensive during most of the day (on-peak hours) then during the night and eventually a small period of the day (off-peak hours); on the other hand, many utilities supply electricity at a reduced rate during off-peak hours… And it is this very fact that is at the core of the ETS Systems (Electric Thermal Storage systems), designed to take advantage of the reduced electricity rates of the off-peak hours.

The mechanism of ETS systems is obvious: during the off-peak hours, the system stores heat (usually in their ceramic bricks) to be used later, by the owner of the equipment. Since the difference of On/Off electricity rates is often very considerable, Electric Thermal Storage solutions can be a good deal. ETS can provide considerable reductions on energy bills.

Note: Electric Thermal Storage is more than just a deal for users. It’s also an efficient environmentally-friendly technology, because electric companies can’t store all the electricity they are producing during the night or certain parts of the day. So, the more the final consumers store part of that excess production to use it later, the less electric power will be lost during the off-peak hours and the less electricity will be required during the on-peak hours.

The situation in Europe and North America

Electric Thermal Storage technology has been developed in Europe before the 1950s, and only introduced in the North America during the 1980s. And it is still in Europe that the ETS solutions are more widespread.

In the United States and Canada Electric Thermal Storage solutions are being embraced by several towns and governmental agencies and power utilities, usually in close association with Steffes Corporation, the leading North American manufacturer of electric storage equipment.

Your utility and the Off-Peak times

Pay attention to the Off-Peak times set by your utility. Off-Peak hours vary a lot. Some utilities utilize a 7 hour Off-Peak, others 8 or 10 or 12 hour Off-Peak, and rates may change at different times.

Besides, some utilities offer more than just the On-Peak and the Off-Peak rates; they may also offer Mid-Peak rates, an intermediate cost per kilowatt.

Electric Thermal Storage Solutions

Electric Thermal Storage solutions are based on a storage core that heats ceramic bricks (or water) to a predetermined temperature level during the off-peak period. The equipment comprises also a set of controls, to detect and control the storage during the off-peak period.

Electric Thermal Storage Systems can be articulated with furnaces, boilers (for hot water heating solutions) or with small space storage heaters.

The room storage units come in a wide variety of sizes (2 to +7 kilowatts), but larger rooms may require more than a storage heater.

Central electric thermal storage systems are more sophisticated solutions. The furnace can combine with heat-pumps (a high efficient electric heating and cooling system) for more energy savings, and the boiler can produce the water for radiant floor systems, radiators, or baseboard heating…

ETS downsides and problems

Electric Thermal Storage systems are prone to leaking and energy loss. Part of the stored energy is inevitably lost. Small storage heaters, for instance, have a heat retention capacity around 40%-60%.

Obviously, the final loss is much smaller if the equipment is located in the conditioned space of the house. But the problem remains, and can make the solution much less advantageous than it seems at first…

Manufacturers of Electric Thermal Storage systems

In the UK and the rest of Europe, companies like Stiebel, Dimplex, Elnur, Creda, Robinson Willey or Sunhouse are particularly well known. In the North America, Steffes and Dimplex are the major names in Electric Thermal Storage solutions.

Warranties

Electric Storage equipment may come with a two to five-year warranty.

In North America, some governmental agencies are offering a first year guarantee on Electric Storage Equipment systems, and also a special commitment: if the customer is not completely satisfied during the first heating season the agency will remove the equipment at no charge and will reimburse the invoice price of the unit. A telltale sign of quality…