It's just a single sentence on the 178-page coalition agreement, but it has enormous consequences for property owners and tenants: Every new heating system installed in Germany from January 1, 2025 onwards is to be operated with 65 percent renewable energies.

Oil and gas heating systems are therefore ruled out.

Even in combination with a solar system on the roof, the prescribed proportion of renewables cannot be achieved in most cases.

According to the plans of the traffic light coalition, the heating of the future is a heat pump that is to run on green electricity.

Julia Loehr

Business correspondent in Berlin.

  • Follow I follow

This means that a type of heating is experiencing a renaissance that had actually already been written off politically.

The so-called night storage heaters, which were installed in many places in Germany after the Second World War, also ran on electricity.

They were easy to install, but not very efficient and, since the introduction of the electricity tax, also quite expensive.

In the meantime, the federal government even introduced a ban on these electric heaters, which was later canceled.

Everything is supposed to get better with the heat pumps – more efficient and greener in any case.

However, when it comes to heating costs, experts warn of a nasty surprise.

Experts reacted with surprise to the coalition agreement

There are currently around a million heat pumps in Germany.

By 2030, it should be up to six times as many, as Economics and Climate Protection Minister Robert Habeck (Greens) recently outlined.

Put simply, heat pumps extract heat from the air or the ground and compress it using electricity so that buildings can be heated and hot water supplied.

In principle, this also works at low outside temperatures.

How well depends on the condition of the building.

For new buildings - insulated, with modern windows and underfloor heating - heat pumps are considered to be well suited.

In contrast, heating older buildings with classic radiators in this way requires large amounts of electricity, if it can be done at all.

However, most residential buildings in Germany belong to this group.

Building experts were therefore somewhat surprised when they read about the quasi-obligation for heat pumps in the coalition agreement.

"The majority of the building stock is simply not suitable for heat pumps," says Dietmar Walberg, Managing Director of the Working Group for Contemporary Building (ARGE), which is recognized both in the construction industry and in politics.

“The heating surfaces are too small, the flow temperatures too high.

That will be extremely expensive for the residents.” A country like Sweden has been using heat pumps for many years.

However, electricity is significantly cheaper there than in Germany, which occupies the top position in the EU in this regard.

Walberg's conclusion on the traffic light heating plans: "This topic has not yet been thought through to the end."