Blazing a trail with 350 heating appliances

The project partners had been working toward this moment for years, and on April 28, 2022, the time had finally come. At Saxony-Anhalt’s representation in Berlin, the German gas and water industries association DVGW, together with E.ON subsidiary Avacon, presented the results of their long-term trial in which 20 percent hydrogen was blended into the natural gas grid. As project leader Angela Brandes explained, the project has shown that it “is technically feasible to inject a much higher percentage of hydrogen into the existing gas network than has so far been provided for in the technical rules of the DVGW.”

“In 2045 we can meet Germany’s entire energy requirement with hydrogen.” These were the ambitious words of Gerald Linke, chairman of the DVGW, who was speaking at the results presentation. He continued: “Contrary to widespread assumptions, hydrogen will be available in sufficient quantities. We have been able to prove this recently in our study which was commissioned by Frontier Economics.”


Here, Linke was making reference to the sustainable heating sector analysis published by Frontier Economics in April 2022 (see fig. 1). The report states that in the year 2030 roughly 290 terawatt-hours of low-carbon or carbon-neutral hydrogen will be available. Around 60 percent of this could be green hydrogen from domestic electrolysis and other European countries – a much larger figure than has been quoted previously by most other forecasts.

Based on these figures, the DVGW outlines a scenario in which enough sustainably produced hydrogen is available, which would mean that there would also be sufficient hydrogen gas left for the heating sector. Up until now, green hydrogen has been frequently hailed the “Champagne of the future” and much too good to waste on heating. Should the association be right, existing gas suppliers and DVGW members will be able to continue using the best part of their assets and retain their current market-leading position as the world enters an era of net-zero.

Linke clearly sets out his aims: “Things mustn’t just stop at political declarations on diversifying the energy supply. It’s a case of unburdening the system at all levels while taking into account continuing electrification.” This statement doubtless refers to the move away from the concept of an all-electric world and toward an energy supply system in which molecules are still expected to play a decisive role. In the DVGW’s eyes, eschewing hydrogen in the heating market would be unthinkable.

Section ready for up to 20 percent hydrogen

Evidence that hydrogen heating actually works comes from Avacon. In its H2-20 project, the network operator investigated the use of gas equipment already installed in existing buildings. Appliances of varying ages and designs typical to Germany were operated on gas containing up to 20 percent hydrogen without having to carry out an extensive replacement program. Angela Brandes from Avacon Netz explained: “Over the past few months, we have been progressively raising the proportion of hydrogen in our gas grid in Jerichower Land and have already successfully blended 20 percent hydrogen by volume. This worked perfectly.” The amended DVGW standard G 260 currently allows for 10 percent hydrogen by volume to be supplied to large parts of the existing housing stock if a separate individual assessment is carried out.

“The project has shown that it is technically feasible to inject a much higher percentage of hydrogen into the existing gas network than has so far been provided for in the technical rules of the DVGW.”

Angela Brandes, project leader for H2-20 at Avacon Netz

In all, around 340 households in Fläming have been taking part since December 2021. The central feed-in point for hydrogen in the 22-mile (35-kilometer) section of the network was located in Schopsdorf where over 350 gas appliances are in service, most of which are used for heating. Firstly, all equipment was recorded and checked by the gas and heat institute GWI in Essen and by the appliance manufacturers. Four appliances deemed unsuitable were changed for new and advanced hydrogen-compliant models.

The proportion of hydrogen injected was raised incrementally from 10 percent to 15 percent and then finally to 20 percent. Testing is being carried out over two heating periods – 2021/22 and 2022/23 – with the 20 percent mark already reached in spring 2022. A further 20 percent injection phase is planned to take place over several weeks this winter.

Public meetings were held to keep domestic and commercial customers up to date and involved in the project. This social engagement is said to have been extremely worthwhile. Berthold Vogel from the sociological research institute SOFI in Göttingen, who provided scientific support to the project, confirmed there had been “high social acceptance in Schopsdorf” which is a necessity when introducing this type of new technology.

Environment minister for the state of Saxony-Anhalt Armin Willingmann, who visited Schopsdorf in March 2022, stated: “Valuable pioneering work is being carried out in Jerichower Land that will enable carbon-neutral hydrogen to flow through existing pipes instead of fossil-based natural gas. […] I was able to witness firsthand the kinds of experiences had by the residents, and those experiences were consistently good.” Angela Brandes is in full agreement, saying that all the appliances used in the trial have been “run through.”

DVGW hydrogen database

Meanwhile, the DVGW continues to shift its focus away from fossil-based natural gas and toward hydrogen. In Linke’s words: “It is incumbent upon us to draw up guidelines for hydrogen.” For years the association has been an important certification body, a role it wishes to pursue within the hydrogen sector in future. For this reason an enormous amount of information has been compiled over recent months in order to create a database that provides a complete list of all hydrogen-compatible components. This database is set to go live shortly.

Policy framework

The building sector has a key part to play in the energy transition. One considerable challenge is the target stipulating that every newly installed heating system must run on at least 65 percent renewable energy from 2024. At present, around a half of all apartments in Germany, approximately 20 million households, are still heated by gas.

Zukunft Gas, an initiative started by companies from the German gas industry, had this to say on the matter: “This target imposes an impossible task on hundreds of thousands of households.” That’s why it’s all the more important, said the organization, that hydrogen readiness is officially recognized and a hydrogen-ready standard is introduced for new gas applications. While heat pump production will indeed be increased, it explained, it would take an additional 60,000 installers to be able to fit them.

Additionally, a municipal heating plan has been called for that will give residents an idea of when, for example, their region will be connected to a hydrogen pipeline. This advance notice is necessary, it has been suggested, since consumers will ultimately be the ones who will need to take action by changing to low-carbon forms of heating.

In July 2022, however, the German government announced an emergency program of climate action measures aimed at the building sector. Klara Geywitz, German housing minister, explained that municipal heating plans are due to be addressed after the summer recess so that climate protection measures can be approved in the fall. Patrick Graichen, state secretary at the German economy ministry, said: “Municipal heat planning is important. Local authorities, municipal energy suppliers, will assume responsibility.”

As it turns out, the raft of measures in the German government’s Summer Package was heralded a great political success. Yet both the emergency program for the building sector and a further emergency program for the transport sector drew disappointment. The DVGW critically remarked: “The assumption that pure gas heating systems can no longer be installed because they are not able to meet the required 65-percent-renewables rule for new heating systems from 2024 is simply wrong. Gas heating systems fulfill this requirement if they operate on biomethane or, in the future, on carbon-neutral hydrogen or when combined with other technologies such as solar thermal.”

“I would say the installation of new gas heating systems in this situation is politically wrong and irresponsible. Germany has a higher dependence on gas, oil and coal than other European nations.” We therefore have a duty to quickly release ourselves from this.

German economy minister Robert Habeck

It has since been announced, however, that other appliances can also be used besides heat pumps and that there are to be transitional periods of up to three years. These periods could apply for instance in the event that heat pumps or installers were unavailable for a short time. Hybrid appliances are also to be ranked more favorably. Even if their output equates to just 30 percent, this could still satisfy the 65-percent-renewables requirement. Green gas heating systems that run on biomethane or green hydrogen are also permitted.

Refit kit for gas boilers

Nevertheless, the impression given by heating system manufacturers appears increasingly to be that hydrogen will be used in converted gas boilers within domestic settings in the future. Fuel cell heating appliances such as those sold by Viessmann or SOLIDpower, by comparison, work on a cogeneration principle in that they produce both power and heat from natural gas. Pure heating modules, like today’s natural gas-fired condensing boilers, will be designed “hydrogen ready” which will allow them to run on 100 percent hydrogen once the burner has been changed.

Rainer Ortmann from Robert Bosch told H2-international: “We, together with three/four other manufacturers, have given assurances to policymakers that from 2025 it will be possible to convert appliances within an hour using a refit kit.” This refit kit is expected to be on sale for a few hundred euros.

Hydrogen competence group

In April 2022 the DVGW set up a “hydrogen competence group of the German energy industry” in order to drive forward the use of hydrogen and encourage the ramping up of the market for hydrogen technology. The collaborative group is made up of various institutions that form part of DVGW’s research network, namely the Engler-Bunte-Institut at the Karlsruhe Institute of Technology, the DBI alongside the DBI-GUT in Leipzig and the DBI-GTI in Freiberg, and the gas and heat institute GWI in Essen.

The DVGW chairman Gerald Linke explained: “The mammoth task of converting our supply to carbon-neutral energy carriers cannot be accomplished without the effective transfer and widespread communication of research results.” Spokespersons for the new group are Gert Müller-Syring and Jörg Nitzsche, both from DBI.

Author: Sven Geitmann

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