How Germany can free itself from gas dependency is a matter of controversy. According to the energy expert Martin Pehnt, drastic measures are also necessary for this. In households, however, it is quite easy to save a lot of energy if politicians provide the right instruments, says the head of the Heidelberg Institute for Energy and Environmental Research in an interview with ntv.de.
ntv.de: The fear of a gas collapse is great in Germany. How do we make it out of gas addiction?
Martin Pehnt: We currently have three major issues. The first question is how we can save gas in the short term with low-threshold measures. It is about precautions where consumers are not dependent on craftsmen. The second question is: How do I prepare for a heating replacement and what alternatives do I have for gas heating? Heating systems often break down in winter and a replacement - for example a heat pump or a heating network connection - has to be organized quickly. Then there is the third question: How can I get my house to be climate-neutral and heated with renewable energies in the next ten years so that I don't depend on a drip from some gas dictators. For this I usually need energy advice or a renovation roadmap. But my idea is to link the first two points. People must be supported in saving gas in the short term and in the future getting rid of it altogether.
How should that look?
I've been asking for a gas savings check for a few months. Experts come into the houses and apartments to investigate where gas can be saved. This can be heating engineers with the obligatory maintenance, chimney sweeps with the fireplace inspection or targeted energy consultants. For example, they can replace thermostatic valves, identify inefficient pumps and find ways to lower the temperature. So not only the room temperature, but above all the flow temperature of the heating. This saves energy losses and is also important if you want to install a heat pump later. It is also about optimizing hot water preparation, for example with timers for circulation pumps and water-saving devices. One thing that everyone can do themselves is to equip the radiator niches and heating pipes with thermal insulation in unheated rooms. That's done quickly.
How much gas can be saved by such measures?
All in all, such a gas savings check can save at least ten percent of gas without major investments - immediately. If you spend a little money, you save even more. A considerable amount of energy can be saved with comparatively little effort.
Of course, that costs money. Should consumers bear the costs themselves?
My wish to politicians is that consumers pay for this gas savings check. If this is granted to all owners of a gas heating system, we are in the order of one billion euros for Germany. This gives us the security of getting through the winter as well as possible. And at the same time we protect the climate. Federal Economics Minister Robert Habeck announced a mandatory heating check on Thursday - it's already going in that direction.
What else can be done?
Of course, such a consultation should also point out changes in behavior: take shorter showers, only heat one room, and so on. But there are also a number of smaller investments, such as checking whether a solar collector can be retrofitted to the roof. At our institute we have installed a small heat exchanger in the shower tray. It preheats the shower water with the warm water that is running off. It costs a few hundred euros, but we can save 10 to 15 percent of the energy we use when showering. However, it is also important to look at the building as a whole. The insulation of an outer wall, basement ceiling or top floor ceiling saves a lot of energy, for example. You have to spend money to do this, but there is also good government funding.
These are all things that depend on the good will of the individual. Is there a risk that in the end not enough people want to take care of it?
There are certainly considerations to make such a gas savings check mandatory. That would be something like if my car had to go to the TÜV. That's where I'll get advice. At the European level, instruments are already being discussed that oblige building owners to carry out renovations. That would of course be stretched over a longer period of time. In Germany, the federal government is also planning to introduce the so-called 65 percent renewable rule. This means that every boiler that is installed from 2024 must be heated to 65 percent with renewable energies. That would be a powerful tool. It is very important to me that these regulations are accompanied socially: for example, through particularly good support for socially disadvantaged building owners or for buildings with a high proportion of social housing.
Many municipalities are currently saving gas at their own discretion. What can a city do effectively?
Every municipality should consider a heating strategy. In Baden-Württemberg and other federal states, certain municipalities are already obliged to submit such a heating plan. It's all about the questions: Which parts of the city are suitable for a bundled district heating supply? Where are gas networks that can be further developed? Where can you switch to heat pumps? Where can renewable energies or waste heat be used? This is a municipal task. There are also considerations to make this mandatory nationwide. But municipalities can do even more. They often have their own public utilities and work closely with energy suppliers. They can submit corresponding conversion offers to customers. Municipalities play a very important role in the heat transition because they know best what is suitable on site.
For example, Berlin is considering no longer illuminating the Brandenburg Gate at night. Are such measures really decisive or is it rather symbolic politics?
In the current situation, I'm all for grasping at straws. Symbolic politics is not bad at all. Many still remember the car-free Sundays from the 1970s. As such, this hardly saved petrol and diesel, but was a symbol of subsequent measures. When the Brandenburg Gate is no longer illuminated, the signal is: We have to use energy responsibly. This has always been neglected in recent years and decades.
Some real estate companies want to reduce the heating temperature of tenants at night or turn off the hot water at certain times of the day. Is that still reasonable?
At the moment we simply don't have the luxury of being able to make decisions; we also need interventions that can be felt on an individual level. Simply because we are in an unprecedented emergency. As long as health is not endangered and basic well-being is guaranteed, such measures must be possible.
However, the impression also arises that the problems are passed on to the socially disadvantaged, while wealthy people do not necessarily have to limit themselves.
This crisis has a very high social explosive force. This has very different consequences. It must be discussed how to financially support the socially disadvantaged. Ultimately, however, it is also about protection so that these households do not have to face exploding costs. Because the bill is usually only paid afterwards. By the time people realize they can't afford it, it's already too late. Measures, communication and state support must mesh here.
How high is the savings potential in the economy? Industry, for example, consumes a great deal of gas.
Many companies have the option of using hybrid heating systems or "bifuel systems" to switch to other fuels or even electricity. We're talking about short-term savings of eight to ten percent of industrial gas consumption. That should be resorted to. There is also a push to set a financial incentive through the auctioning of savings measures and to demand the implementation of economic efficiency measures. But of course it is also the task of the Federal Network Agency to determine which companies are unavoidable and which must be made responsible for saving more gas. This is a regulatory task for the transitional period.
Is the gas crisis also an opportunity to promote the switch to renewable energies, or do you see a tendency to relapse?
We need to separate what is happening in the short term and what is being initiated in the longer term. In the short term, this year, we will use more coal and more LPG, and even now we still have quite a lot of gas in our power system. But the amendment to the Renewable Energy Sources Act got a big ball rolling and eliminated bottlenecks. If we continue along this path, the expansion of renewable energies will succeed. Overall, as a result of the war and the noticeable effects of climate change, the realization has grown everywhere that renewable energies are an outstanding part of the solution.
Marc Dimpfel spoke to Martin Pehnt
