(Berlin/Frankfurt, July 27, 2022) In the face of worries about a potential gas supply shortfall in the coming winter, some people are currently proposing that private households look to supplementary heating from electric-powered, mobile direct heating appliances (fan heaters, radiators, space heaters etc.) as a precaution. Demand for these relatively inexpensive devices has already shot up and is expected to rise further.
“We are worried about this current development, since our power grid is not designed for a sudden additional load of that magnitude,” says Dr. Martin Kleimaier, head of electrical energy generation and storage at the Society for Energy Technology in VDE (VDE ETG). “Because these heating devices are simply plugged into power sockets in the home, they cannot be turned off by the grid operator in the event of a potential network overload – unlike electric heat pumps or storage heaters,” Dr. Kleimaier explains.
Use gas heating in moderation and increase its efficiency
Russia is currently supplying only a fraction of its contractually agreed gas deliveries. That does not mean, however, that gas heating customers will have to freeze this winter. For one thing, private customers are protected by law; for another, Germany also receives natural gas from Norway, the Netherlands and Belgium. To cover the shortfalls caused by the reduced supply from Russia, we will continue to obtain more electricity from liquid natural gas (LNG) bought on the global market and fed in at terminals in neighboring European countries. A new LNG terminal in Wilhelmshaven, Germany, is set to begin operations as soon as this winter. Feeding more biogas into the gas distribution networks could also help compensate for the dwindling gas supply.
Frank Gröschl, head of technology and innovation management at the DVGW, has a clear recommendation: “You can certainly keep using gas heating in your home. But it’s advisable to start taking efficiency-boosting measures now in the summer to get gas heating systems ready for winter. Lowering the room temperature by one degree brings energy savings of six percent. Adjusting the heating controls to people’s actual behavior, controlling radiator thermometers online via app, and hydraulically balancing the heating system are just a few of many swift measures that can both increase efficiency and reduce consumption. Regular maintenance work on gas boilers should be performed before winter to reveal and remedy any inefficiencies at an early stage. These measures are already beginning to take effect, as demonstrated by the reduction of about 14 percent in gas consumption compared to last year. We can lower it even more.”
Even in the event of a gas shortage, gas will remain in the distribution networks to supply heating customers. For technical reasons alone, it is not easy to simply shut down a local gas network for a whole street or district. Safety mechanisms in the buildings are triggered if the gas pressure falls below a certain threshold or if the gas stops flowing. Each individual safety valve would then have to be unlocked by trained personnel. That would require a huge amount of time in practice, since they would have to carry out the procedure in every single building.
Fan heaters could cause overloads and power outages
Electric direct heating appliances such as fan heaters are not a suitable alternative for reducing gas consumption. Apart from the high costs associated with heating this way, a large number of these devices operating at the same time can adversely affect the power supply. “The simultaneous additional power consumption can trigger the overload protection mechanism, thus causing a power outage in the affected parts of the grid,” explains Prof. Hendrik Lens, deputy head of the VDE ETG division. “And restoring the power supply is also no easy task. If not enough affected customers manually switch off their devices, the power will immediately fail again when reactivated by the network operator,” Prof. Lens explains.
In addition to local network overloads, another problem is that our power plants currently lack the capacity to support this extra load. A simple calculation proves the point: about 50 percent of the roughly 40 million households in Germany currently heat with gas. Assuming that, on a very cold winter day, half of these households on average use an electric heating device typically drawing 2,000 watts, that would amount to an additional consumption of roughly 20 gigawatts. That would increase Germany’s current annual peak load by a quarter, which neither the power grid nor the available power plants could handle, especially considering that gas power plants would be unavailable in the event of a gas shortage.