Podcast “Learned something again”: Heat with electricity? “Only a good idea for emergencies”

Germany is preparing for a gas shortage. Many people buy electric heaters for fear of a cold apartment in winter. However, heating with electricity is by no means cheaper than with gas. Mass hook-up could also trigger a collapse in power systems.

Nobody wants to freeze in autumn and winter. After all about half of all German households heats with gas. And that could be scarce in the cold season. In addition, the price of gas continues to rise.

Many people therefore buy an electric heater. One in ten Germans bought a fan heater, radiant heater or radiator in the past six months Comparison portal Verivox out in a poll. In addition, almost 35 percent more electric fan heaters were sold in Germany from January to June than in the same period last year. A quarter of people think that electric heating would be cheaper overall.

“If someone buys an electric heater because they want to have an emergency backup if the gas heater goes out, then it’s a good idea. If someone thinks it’s to save money, it’s cheaper than gas, then it’s a bad idea “, says Reinhard Loch in the ntv podcast “Learned something again”. He heads the energy efficiency group at the consumer advice center in North Rhine-Westphalia.

Electricity twice as expensive as gas

Electric heaters are not expensive. Simple fan heaters are available from around 30 euros. However, heating an apartment with them is more expensive than with gas. The price of electricity is much higher in comparison: A kilowatt hour of electricity costs more than twice as much as the same amount of gas. It currently costs about 42 cents on average. The average gas price is around 18 cents per kilowatt hour.

Reinhard Loch does not expect the relationship to change in the future, even though electricity is becoming more and more expensive. The heating costs for a 70 square meter apartment heated with gas or oil would be around 1000 euros a year. “If you were to completely switch to electricity, it would be at least 2,000 euros, maybe even 2,500 euros,” calculates Loch.

In addition, the electric heaters could pose a threat to the power grid. The Federal Ministry of Economics writes in a Analysis of the power supply in the coming winter 2022/23that “safe operation of the electricity supply network is still guaranteed”. But the electricity suppliers are sounding the alarm. The power supply is not designed for such an additional load, they also say Industry associations DVGW and VDE. The local grid could be overloaded – power outages would then be likely.

Power grid not designed for millions of electric heaters

“The gas network is designed so that we can all heat at the same time. The electricity network is not,” says the energy expert. “If all 20 million households that heat with gas also heat with electricity and equip all rooms with small fan heaters and electric radiators, that would be problematic for the networks. A fuse would blow in the street or in the neighborhood.” In addition, the electricity suppliers could not make this capacity available at all. “We can no longer connect so many coal-fired power plants to the grid for the total peak output that will then be required.”

So we would need a lot more electricity if all people who have gas heaters used electric heaters instead in the winter. Loch calculates that this cannot be compensated for in the short term.

would all If 20 million households have three or four electric heaters in operation at the same time, this is extrapolated with a connected load of Expect 100 gigawatts at five Kilowatts per apartment, so Loch. “That corresponds to practically the entire capacity that we currently have in terms of coal and nuclear energy in the grid. They are then fully utilized in one go, so to speak, and we still have the rest of the electricity consumption. That would practically mean a doubling of the electricity consumption from the peak output and We don’t even have that in stock.”

Nuclear hardly a substitute for gas flow

Not only the demand for heaters and Co. threatens the power supply in Germany. If there are gas shortages, gas power plants that generate electricity may have to be shut down. Gas-fired power plants currently account for around 15 percent of our electricity supply, says energy expert Loch. “But the trend is declining because the gas is so expensive and the electricity suppliers no longer like to use it.” In addition, the gas for heating should be reserved. Instead, coal-fired power plants are to be put back on the grid. Just like the coal-fired power plant in Mehrum, Lower Saxony, earlier this month. In addition, longer service lives of nuclear power plants in Germany are being discussed.

However, nuclear power plants would only replace a small part of the electricity from gas, only up to 1.5 percent, said the Association of German Engineers ntv.de. Because many gas-fired power plants can – if necessary – be ramped up to peak performance in just a few minutes. This prevents power outages when more is consumed. Gas-fired power plants ensure that the power grid remains stable. Nuclear power plants cannot do that. They cannot simply be turned on or off.

Another problem for the power supply is the declining energy supplies from France. More than half of France’s nuclear reactors are currently off the grid. According to the Federal Network Agency, Germany exported five times more electricity to the neighboring country from April to June than it received from there. Usually it’s the other way around. In the past two years, France has supplied more electricity to Germany than it has received from there.

“Electricity mix in Europe is stable”

Nevertheless, the power supply in Germany is currently safer than the gas supply, says Reinhard Loch. “We are also part of the European network. Some of the neighboring countries generate their electricity more from coal, some more from nuclear power, some more from wind and sun. Other countries are ahead of us there. The electricity mix in Europe is quite stable .”

Nevertheless, electric heaters should not be used permanently, but only as emergency heating, the energy expert makes clear in the podcast. For example, if there is a gas shortage in certain regions, the gas pressure falls below a critical limit. “Then certain protective valves in the house, on the street, but maybe also in the whole city are automatically shut down and the heating fails. It may take a few days before the gas appliances are started up again. It’s for such an emergency situation Of course, it is possible to supply individual rooms with a fan heater or with an electric radiator.” However, one or two devices per apartment are sufficient.

But the simplest recipe is now: save energy. The EU countries want to voluntarily save 15 percent of gas by March next year, according to the gas emergency plan that came into force last week. Germany even wants to use 20 percent less gas. Many municipalities are already saving, lowering the water temperature in swimming pools and turning off heating and hot water in schools and gyms.

The federal government is planning strict regulations for autumn and winter. Among other things, public buildings should only be heated to 19 degrees. And tenants no longer have to heat their apartments up to a certain minimum temperature. After all: if you lower the room temperature by just one degree, you can already save six percent of energy.