Is electric heating making a comeback?

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1 Is electric heating making a comeback? An ecological and economical answer for modern living Electric heating has always been unbeatable for safety and comfort. But it is expensive, according to conventional wisdom. Today, that image seems more and more undeserved. Both technology and our way of living have changed significantly. In an increasingly urbanized environment, with better insulated dwellings, electricity could very well turn out to be one of the most efficient ways of heating. Food for thought. Pushing passive houses Electric heating and well-insulated houses go hand in hand. However, using electrical heating in a poorly insulated country cottage in a cold climate is certainly inefficient. Luckily, this situation only applies to a small fraction of dwellings in Europe. The level of insulation in European buildings continues to increase. With the implementation of the EU Directive on the energy performance of buildings in 2006, Member States are encouraging high insulation levels, super insulated windows, and rigorous energy design focused on eliminating thermal bridges and infiltration. Heat losses are being minimized as a result. So-called low-energy houses and passive houses use 75 to 95% less energy for space heating than conventional buildings. They can preserve a constant, comfortable temperature with only minute heating pulses. With its quick response time and ease of control, electric heating is more than a valuable option. Modern way of living, modern energy requirements Electric heating systems only consume energy at the time and the place where it is needed. That makes them the most effective source in the case of periodic heating demand distributed over time and/or at a specific place. The heating pulse in lowenergy houses, such as the one mentioned above, is one example. An electrical resistance immediately starts and stops consuming when the thermostat switches on or off. Hydronic systems though, with an inherent inertia due to the water distribution network, are saddled with a slow response time and consequent energy losses. AIE, J. Chantraineplantsoen 1, 3070 Kortenberg - Belgium 1 of 6

2 7,000 6,000 Consumption (kwh/year) 5,000 4,000 3,000 2,000 Hot water Heating Total 1, Year of construction Figure 1: The energy demand per customer is decreasing. Investing in a single network that serves all energy applications in the house becomes more costeffective than multi-utility investments [GIFAM] A quick response time is also a welcome convenience in our hurried and fragmented lives. The current trend towards multi-dwelling houses and apartments places a premium on individually controllable heating systems. Even within the dwelling itself, occupancy rate of rooms is subject to high variability. What is the purpose of installing a central system, when its full capacity is only used occasionally, such as when the children visit? Would not a single utility network serving all energy applications in the house be a lot more cost-effective? Compared to central heating, electric heating allows for more intelligent and thus effective use of energy. Different rooms can have different temperatures, according to the instant need. The kwh is not the only cost It is true that energy companies charge more for one kwh of electricity than for the same kwh of for instance natural gas or oil. But you can t see the total cost of an energy service on your energy meter. The total energy bill of electric heating is of the same order as that of other forms of energy (see figure 2). The investment cost for electricity is about two to five times lower than for other heating solutions, and with an even longer lifetime. This is a cost reduction, by the way, that makes it possible to invest in better insulation and ventilation. AIE, J. Chantraineplantsoen 1, 3070 Kortenberg - Belgium 2 of 6

3 Cost to consumer (euro/m2/year) Gas Electricity Oil Figure 2: When taking into account all maintenance costs, the final invoice for electric heating is approximately the same as other energy sources [GIFAM] Once installed, electric heating devices require very little if any maintenance. No need for regular verification by an expert, no chimney sweeping, no purging of the pipes. Moreover, electricity is the only method where the energy consumed is entirely converted into effective heat at the point of use. Once delivered to the consumer, there are negligible energy losses compared to those incurred in distribution by water pipes, energy consumption by auxiliary units such as circulator pumps, inefficient combustion in the boiler, etc. And electric heating systems save space in the home (boiler room, wood pellet stove & storage, oil tank) that becomes available for other purposes. Looking beyond buildings To a large extent, the cost of electricity is determined by the cost of its distribution. This means a grid, with largely fixed asset costs, delivering electricity to consumers, and the ancillary services necessary to balance supply and demand at all time. In high efficiency houses that use low amounts of electricity and heat, the share of this fixed cost in the total cost becomes relatively high. Distribution cost increases to 13 c/kwh for electricity consumption below 2,000 kwh/year per consumer [Elder] (not including the cost of generation, transmission, or taxes). For an all-electrical passive house, using 5,000 kwh/year, distribution cost would decrease to 5 c/kwh. Saving 8 cents on 2,000 kwh means 160 euro per year, which at today s prices buys between 1.6 and 8 MWh green certificates per year, enabling the financing of sustainable energy projects. AIE, J. Chantraineplantsoen 1, 3070 Kortenberg - Belgium 3 of 6

4 The efficiency of electricity generation The above mentioned conversion factor of 100% for electricity is only valid at the point of use. To compare the overall energy efficiency, one should take into account the efficiency of electrical power plants. Modern power stations convert up to 60% of the primary energy content of fossil fuel into electricity. That is still low when compared to the 90% reached (at full capacity) by the newest high-efficiency boilers for domestic use. But beware for misinterpreting this rather theoretical number: it ignores ageing of the device, intermittent operation of the boiler and assumes great discipline on the part of the user in perfectly maintaining boiler and distribution network. For instance, are the burning controllers meticulously tuned throughout the installation s lifetime? In favour of wind turbines and solar energy The European electricity generation park is highly diversified. Electric power is mainly produced from gas, coal, nuclear energy, hydro, or wind. The consumer price does not depend on a single fuel source. An oil or gas boiler on the other hand, exhibits the price fluctuations of a single fuel for its entire lifetime. A surprising advantage of electric heating is its ability to assist deep penetration of intermittent renewables in the electricity generation network. Wind turbines for instance increase the need for efficient energy storage. Electric heat can be stored with 95% efficiency, compared to 50% for hydrogen, and 70-80% for batteries. It seems that the role of electric heating in modern times is far from played out. It s on its way to being a most ecological and economical answer to real life challenges. AIE, J. Chantraineplantsoen 1, 3070 Kortenberg - Belgium 4 of 6

5 [Frame I] Some advantages of electric heating Reliable - No toxic or dangerous emissions at the point of use (improved urban air quality) - No noise pollution at the point of use - An impressive safety record - No storage of dangerous or toxic substances necessary Cost-effective - 100% efficient at the point of use - No annual maintenance required, except periodic inspection Low investment - Electricity as an energy carrier serves all energy services in a dwelling with a single network - Saving space in the dwelling (boiler room, fuel storage, chimney) Comfortable - Constant temperature in a room (max. 5% variation) - Ease of use, comfortable, and clean - Total control: heating at exactly the temperature, time, and location desired [Frame II] European Union Energy Performance of Buildings Directive The Directive promotes the improvement of energy performance of buildings within the Community, taking into account outdoor climatic and local conditions as well as indoor climate requirements and cost-effectiveness. It was published in the Official Journal on the 4 January Each EU member state is required to make the Directive law by the beginning of AIE, J. Chantraineplantsoen 1, 3070 Kortenberg - Belgium 5 of 6

6 [Streamer] Electric heating allows for more intelligent and thus effective use of the energy. [Streamer] In an electrical resistance heating device, the energy consumed is converted entirely into effective heat. [References] [GIFAM] Livre Blanc, Les appareils de chauffage et chauffe-eau electriques, 2004 [Elder] Leith Elder et al, A Generic Techno-Economic Model for Analyzing Electricity Distribution Networks AIE, J. Chantraineplantsoen 1, 3070 Kortenberg - Belgium 6 of 6