Energy consultant in an interview
“Most are completely insecure and overwhelmed”
06/03/2023, 2:28 p.m
The traffic light heating law is not only causing unrest in politics. Many homeowners are concerned about its practical implications. In an interview, energy consultant Stefan Bolln reports on his experiences. He is chairman of the interest group for energy consultants in Germany and treasurer of the SPD Schleswig-Holstein. He works as an energy consultant and chimney sweep in Northern Germany.
Mr. Bolln, politicians are still struggling to shape the planned building energy law, but many homeowners are already concerned about its practical effects. What are you currently experiencing in your work as an energy consultant?
Stefan Bolln: Most people are completely insecure and overwhelmed by the situation. This is also the fault of politics. The problem is that it is not just about the costs associated with a new heater, there is also a system change taking place. Most have had oil or gas heating for decades and cannot imagine that renewable energy could work in their homes. You have to take the citizen and stoker with you.
Against this background, how do you view the dispute in the traffic light coalition?
We are all waiting for clarity. It bothers me that individuals emotionalize the topic and point fingers at others. The political discourse is fine, but please do not shorten it, but factually correct. Maybe everyone needs to talk to each other properly and profile themselves less.
As an energy consultant, how do you approach the system change you mentioned?
I always look at the whole building, i.e. the shell, the roof, the radiators and the heating. Where is energy consumed? Where can you save energy? Then I make calculations and suggestions for the change. In the end, most are surprised by the good possible solutions.
The calculations are about more efficient use of energy?
In each individual case, the heating capacity must be determined. After all, houses have a heating system in the basement, i.e. a heat generator such as oil or gas, and several radiators that go through the entire house. In winter, they usually have a system temperature of up to 90 degrees in the flow. If we then switch to a heat pump, for example, the temperature has to go down to 55 degrees or less. This means that the radiators have to be significantly enlarged to get the same performance. This is something that can be prepared before the heat generator is actually changed. My tip to everyone who is renovating: Don’t aim for small, but big for the heating surfaces.
In old houses, however, larger radiators are usually not enough.
Yes, houses from the 1950s to 1970s need to be re-insulated up to the top floor, maybe you need new windows. But you can prepare for all of this if the heating system is only ten or 15 years old today. You make an overall plan and then implement everything step by step within 15 years.
Tell me about a solution in the specific case of a one- or two-family house.
I am currently working on a terraced house, built in 1962, which has been heated with gas for 20 years. New windows were installed in the living room ten years ago, and three new ones are still to come. The north wall of the building, the top floor ceiling and the basement exit have to be insulated. The radiators have already been enlarged. Customers are preparing for the conversion and in two to four years they can simply replace the gas heating with a heat pump. Then the prices will probably also be lower because the production capacities will be increased and craftsmen will be more readily available again.
What is the cost of this case?
The customer will partly do the insulation himself, the windows are between 2,500 euros and 3,000 euros. The most expensive is the heat generator. I think in the end it will be a sum of 25,000 euros, of which 40 percent is currently subsidized. The bottom line is that this is not much more than the installation of a gas heater. In return, the customer will save a lot of energy in the future – even before the heat pump is there.
Some believe that a heat pump is inevitably associated with underfloor heating.
That’s what the critics always say, but that’s wrong. It is true that we need larger heating surfaces, but this can also be wall or ceiling heating. The average Joe has a radiator under the window. If I make it just 30 percent larger, I can lower the heating temperature and still have the same performance. That’s simple physics.
How many would now prefer to buy a new gas or oil heating system while it is still possible?
There are certainly people who do not want to embark on a supposed adventure. But they should be careful, because the heating that is being replaced could have been running for another five years. And in five years’ time we will be much more advanced with new technologies than we are today. At the same time, it is clear that gas prices will rise and trading in CO2 certificates will become more expensive.
Is a heat pump always the solution?
No, the alternative is local or district heating systems. You don’t look at the individual house, but one or more streets. But if there is no heat conduction, the only option is individual heating. In my opinion, hydrogen should not be used for heating in houses, even if it seems to be possible in certain cases. Pellet and biomass systems are currently being criticized, but I don’t understand why. Ultimately, there will have to be a solution for every house.
What do you not understand about the arguments of the critics of pellet and biomass systems?
Until recently, the biomass and pellet heating was subsidized with up to 55 percent, now only with a maximum of 20 percent. These systems are said to be unsustainable, but it depends on the house. In some houses, pellet systems are better than heat pumps. This must also be reflected in the funding and discussion.
Vicoria Robertz spoke to Stefan Bolln
The interview is first at Capital.de appeared