Electric thermal storage heating systems (ETS) were historically installed (and still are, in large part) to take advantage of night-time, off-peak electricity rates. If your utility has off-peak electricity rates, and if the difference between them and normal rates are significant, electric thermal storage heating is an option to consider. The running costs and the advantages of electric storage heaters depend largely on these factors.
On the other hand, if you are producing your own eletricity (through, say, a solar PV system) or if your home is very energy-efficient, electric storage heaters can be a good option, even without off-peak rates.
Be aware, anyway. Electric storage heating is prone to energy loss...
Electric Storage Heaters...
»» do not provide energy savings;
»» they benefit from night-time off-peak electricity.
»» they produce and store heat to be used later;
»» they are prone to energy loss and can be innefective in many cases.
Common electric thermal storage heaters
You may consider several electric storage systems: central furnaces incorporating special ceramic blocks; storage tanks and boilers; electrically heated water systems with ceramic blocks, and so on.
But the commonest solution is room storage heaters, which come in a wide variety of sizes (2 to 7+ kilowatts). Most storage heaters are wall-mounted and they look a bit like common panel radiators.
Electric Storage Heaters problem Number One: Energy Loss
Electric Storage Heaters are prone to leaks and energy loss.Electric Thermal Storage Heaters Mechanism
Electric Thermal Storage Heaters use low-priced electricity (off-peak periods) to store heat in their ceramic bricks; stored heat is then used later, typically during daytime. If the difference in the On/Off electricity rates is considerable, that can provide lower energy bills.
Part of the stored heat – sometimes estimated at 40%-60% - is lost during the storage period. New and more efficient electric storage heaters can reduce these percentages, but they can't be elliminated.
Obviously, loss is minimized if the storage heater is located inside the conditioned space of the building; that's a way of partially overcoming the problem.
But the issue of the effectiveness of the system remains; the advantages of electric storage heaters are often grossly overestimated by sellers.
You should consider the pros and the cons of electric storage heating, taking into account your climate, the energy efficiency or your home, the electricity rates, your needs and schedules and the costs and advantages of other home heating alternatives.
Below we list several factors that you must assess, before deciding to install or not an electric storage heater.
1 - Best heating strategy & electric storage heaters
Do not forget that the best heating strategy is to reduce heating demands to very low levels through very high levels of insulation, air sealing and high-performance windows. If your are building a new home of remodeling, consider this strategy. Only then electric heating (and possibly electric storage heating) will make sense.
2 . Price and savings
The price of new storage heaters start at about $250-$400, and increases with size.
On the other hand, according to Dimplex, the world leader on electric storage systems, the current off-peak electricity rates (in the USA) for space and water heating are approximately 50% of standard electricity rates, which provides potential electricity bill savings of about 50%...
These savings are significantly overestimated, due to inevitable heat loss, but are a reference of the maximum possible savings provided by electric storage systems.
3. Electric storage heaters vs. gas heating systems
Storage heaters have advantages of their own: the pirrice and installation costs are low when compared with those of central systems, and its installation is far easier and inexpensive.
Besides, compared to gas central heating systems, storage heaters have very low (next to zero) maintenance costs.
On the other hand, electric systems can be expensive to operate, for large needs.
Bottom line: leaving aside the installation costs of central heating systems, the advantages of electric storage heates depend on your heating needs and electricity/gas consumption.
4. Electric storage heaters and solar PV and other renewable sources of energy
For those who produce their own electricity it may advantageous to use electric storage heaters.
Once more, all depends on the electricity rates, but it may be advantageous to use electricity produced by a solar PV system (or other system) during the day to charge the storage heaters, and to release the heat later when people get home.
5. Electric storage heaters vs. Electric heat pumps
Electric air source heat pumps, depending on their type, can produce 2, 3... times more heat than the electricity they use.
Some new models are able to cope with very low temperatures, that is, down to -13ºF/-25ºC. The effectiveness of these heat pumps is no more confined to moderate climates, and are an excellent heating option for all-electric homes, with very high levels of insulation.
In other words: they can be a more effective choice – less prone to problems such as overheating - than electric storage heaters.
6. Storage heaters with or without thermostatic controls
New storage heaters with thermostatic controls can helto p keep the room at a specific temperature. They can replace with advantage the output controls of older storage heaters, though heat losses are always difficult to minimize.
7. Electric storage heaters and energy waste
It’s not easy to forecast sudden changes in ambient temperature, and we should not forget that electric storage heaters involve charging the heater the night before.
In other words: you may encounter situations where you need more heat than expected the previous night (forcing you to use more costly peak time electricity). But you may also face the opposite situation, due to changes in weather.
8- Size and controls of electric storage systems
The size of the heaters dictates how much heat you can take from the system. So although you can install small storage heaters, they may not be able to provide all your heating requirements.
On the other hand, oversizing can lead to overheating problems and to electricity waste (due to heat losses). There are many cases where users use storage heating inefficiently or ineffectively.
9. Manufacturers of Electric Thermal Storage systems
Electric storage units typically come with a two to five-year warranty.