Climate-neutral heating with hydrogen – solutions from Viessmann

More than 90 percent of the approximately 21 million heating systems in Germany are still operated with natural gas or oil. However, the death knell has already been sounded for these fossil fuels. In order to avoid CO₂ emissions in Germany and the EU as completely as possible, electricity and renewable energy sources will play an important role in the future. Green hydrogen in particular is seen as the logical way of making the building sector climate-neutral. It is produced from water in a CO₂-neutral process using electricity from wind power and photovoltaic systems and creates no climate-damaging emissions when it is burned. 

Viessmann low temperature boilers

Protect the climate and save money

The use of hydrogen and the electrification of the heat supply must go hand in hand. If, in the future, we were to rely exclusively on electricity to operate heat pumps or electric infrared heaters to heat buildings, a costly expansion of the electricity grids and reserve power stations would be necessary and vital in order to ensure security of supply.

By contrast, the existing gas grids can be used for hydrogen, meaning that substantially less investment would be required to convert our energy system. According to a pilot study by the German Energy Agency (dena), this could save around 260 billion euros by 2050.

And there's more: hydrogen can help to substantially reduce greenhouse gas emissions with almost immediate effect. Just adding 20 percent hydrogen to the natural gas grids would reduce CO₂ emissions by around seven percent – year after year. A quick and effective contribution to climate protection. All the more so since, according to a recent survey, two thirds of Germans can imagine themselves heating with hydrogen if no CO₂ is produced in the process.

A Viessmann wall mounted appliance as envisaged for operation with a natural gas/hydrogen blend

Expand and use hydrogen infrastructures

The expansion of the necessary infrastructure for the production, storage and distribution of hydrogen will be driven forward in the coming years. In the summer of 2020, the Federal Government presented its National Hydrogen Strategy and intends to make a total of nine billion euros available. Almost at the same time, the EU Commission published a hydrogen strategy: hydrogen production with renewable energies is set to increase to up to one million tonnes by 2024, then to ten million tonnes by 2030.

Expanding hydrogen infrastructure (illustration: ©SmartQuart)

An increasing number of pilot projects are already being supported. For example, an entire hydrogen infrastructure is currently being built in Kaisersesch (Rhineland-Palatinate) – from the generation of renewable electricity for the operation of the electrolysers, through to the storage and distribution of the hydrogen and ultimately to its use in the heat and power supply sectors, as well as for industry and transport.

Solutions for the future

Viessmann is taking responsibility for the living spaces of future generations. To ensure that climate-neutral as well as reliable and affordable heating of our homes is possible in the future, the company is developing "H₂ ready" heating appliances.

With the "H2 ready" condensing boiler, Viessmann will not only be launching an innovative heating appliance on the market, but will also be offering security for the future, coupled with the high levels of reliability we've come to expect of the German company with over a century of experience. 

Building on the proven gas condensing technology of the Vitodens family, burner components, along with the combustion, flame monitoring and control systems, are currently being revised to adapt them to the specific combustion properties of hydrogen. The aim is that the new wall mounted units can be switched easily and quickly from operating with natural gas or natural gas/hydrogen blends to pure hydrogen. This will offer system users maximum futureproofing in the transition phase from natural gas to hydrogen.

Test rig with prototypes of the "H₂ ready" gas condensing boilers at Viessmann.

Once the prototype testing phase has been completed, the appliances will undergo qualification and durability testing before the start of the practical trials in Kaisersesch in 2023. The market launch is currently scheduled for 2025. By then, it's expected that there will be further regional gas grids exclusively distributing hydrogen to households and industrial enterprises.

Photo: "H2 ready" appliances for operation with pure hydrogen on the test rig at the Technology Centre, the Viessmann Climate Solutions SE research and development hub.

Operation with up to 30 percent hydrogen is here already

As an innovation leader in the sector, Viessmann has already made it possible to use hydrogen efficiently for heating. The modern gas condensing boilers are H₂ ready, which means they can be operated with natural gas blends containing 20 to 30 percent hydrogen. Builders or renovators opting for this type of heat generator are thus ideally prepared for the forthcoming evolution in our energy system. The following heating systems and product solutions are certified for the use of hydrogen:

  • Vitodens gas condensing heating system
  • Vitovalor fuel cell heating system
  • Vitomax industrial/commercial boilers
  • Vitobloc combined heat and power (CHP) units
Viessmann Vitovalor PT2 fuel cell and Vitocharge VX3 power storage system

Hydrogen as an energy supplier for the fuel cell

Alongside oxygen, hydrogen is the most important energy source for the fuel cell. Hydrogen has already proven its suitability as an energy source for fuel cells in vehicles and ships many times over. It is also being used more and more often in residential settings. In Japan alone, where technology is valued very highly, sales of fuel cells for stationary applications have risen to more than 200,000 since 2009. This clean and forward-looking technology is used in the Vitovalor PT2 and Vitovalor PA2 heating appliances. They have been developed jointly by Viessmann and the Japanese technology group Panasonic. Hydrogen is obtained in a gas reformer in the presence of a catalyst. The source material for this is the cleanest of the fossil fuels, natural gas.

Vitovalor PT2 fuel cell heating

Climate-friendly process generates heat and electricity

In an electrochemical process, the hydrogen, which has been separated from the source fuel, is split and at the same time, oxygen is added. This results in the generation of both power and heat. The type of combustion that takes place in conventional condensing boilers does not occur. This electrochemical process is also referred to as cold combustion. Experts are of the opinion that CO₂ is one of the main factors causing global warming. Hydrogen on the other hand releases mainly water during the process in the fuel cell, making it very environmentally responsible. Its use also reduces the consumption of limited fossil fuel reserves.