Source: Energy & Management Powernews, July 29, 2022
Heating fans, radiators and electric heaters are in demand as rarely before. VDE, DVGW and utilities now warn of a possible overload of the networks.
They provide a "terribly high electricity bill", have a "catastrophic eco-balance" and burden the power grids "massively": Andreas Huber, authorized signatory at the municipal utilities Erding, warns in conversation with this editorial forcefully that in the coming winter households could cover their heating needs with electric heaters. "Every additional kilowatt hour of electricity we consume comes from fossil fuel power plants," he says. "Conditional on the efficiencies in the power plants, much more primary energy is used when I generate heat via an electric fan heater than when I heat directly in the house."
Adding to this is the possibility of grid overload: "A typical fan heater has 2 kW, operating it is a massive increase in the power of a home." Unlike other large consumers in the home, such as the microwave, a fan heater runs not just for a few minutes, but for several hours at a time if necessary, he said. In addition, "there is a high probability that the neighbor downstairs is running his appliance at the same time."
Power failure and lack of capacity
Before an overload of the networks and a possible blackout also warns Hendrik Lens, deputy head of the Energy Technology Society (ETG) department at the Association of Electrical, Electronic & Information Technologies (VDE) in a statement of the industry association: "With such an additional, simultaneously occurring load, it can come to a response of the overload protection and thus to a power failure in the affected network areas. Restoring the power supply also proves difficult. If as many affected customers as possible do not switch off their heaters manually, a connection attempt by the network operator would immediately lead to a renewed shutdown."
In addition, there is the problem that the current power plant capacity is not sufficient for these additional loads. For example, about 50% of the approximately 40 million households in Germany currently heat with gas. If, on a very cold winter's day, an electric heater with a typical power consumption of 2 kW were to be in operation in half of these households, this would result in an estimated additional offtake capacity of around 20,000 MW. This would correspond to an increase of the current annual peak load in Germany by one quarter. Neither the power grids nor the existing power plants would be able to cope with this - especially as gas-fired power plants would also not be available in a gas shortage situation.
Demand for fan heaters doubled
In fact, however, DIY stores are registering a significant increase in demand for electric heaters, convectors, radiators and fan heaters. According to a spokesman for the Hornbach DIY chain, demand has doubled compared with the previous year. "Extremely strongly" it rose again since proclamation of the second stage of the emergency plan gas on federal level, so the speaker opposite our editorship. At many market locations radiators are currently sold out - and that, although the actual season for this commodity area traditionally begins only in the fall.
Equally enormously increased is the demand for fuels, according to the spokesman of the DIY chain, with a preliminary peak in March and April 2022. The demand is 100% above the previous year since January for pellets, he said. Firewood, lignite and wood briquettes are up 35% to 55%, he added. With discussions with the clientele in the markets one hears again and again of the desire to be self-sufficient and prepared for emergencies.
Gas heatings can continue to run
Thereby nobody must fear not to be able to operate its gas heating in the winter, so Frank Gröschl, director of the technology and innovation management with the German association of the gas and water specialist (DVGW). Even in a gas shortage situation, gas remains in the distribution networks with which the heating customers are supplied. For technical reasons alone, a local gas network cannot simply be switched off. Safety devices in the buildings would be triggered if the gas pressure fell below a minimum level or if the gas networks ran empty. Each individual safety valve would then have to be unlocked by specialist personnel. This would be feasible in practice only with very high expenditure.
Recommendable is however, so Gröschl, now in the summer maintenance and efficiency measures at the gas heatings to address. Fast-acting measures to increase efficiency and reduce consumption are about:
- the adjustment of the heating control to user behavior,
- the online control of radiator thermostats via app
- and the hydraulic balance of the heating system.
Author: Katia Meyer-Tien
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