Re-thinking Heat

Converting the enormous quantities of currently unused waste heat into usable heat is one of the biggest opportunities and challenges in the heat and energy transformation context.

Industry, commerce, biogas plants and other CHP (combined heat and power) plants very often release thermal energy into rivers and the atmosphere without putting it to any further use. Yet waste heat could be used to cover up to 30 % of Germany’s total heating requirements in the building sector CO2 – free.

Heat sources

For the development of a successful heat transport project, a waste heat source with a heating capacity of at least 300 kW are required. This source should be located no further than 15 km away from the heat consumer.
The following plants, among others, are possible heat sources:

Waste recycling/ waste incineration

During waste incineration, heat is released in the form of flue gas. The flue gases, which have a temperature of up to
850 °C, not only have to be cleaned but also cooled in an evaporation process before being released into the environment.

Currently, around 70 waste incineration plants are in operation in Germany. In all of them, part of the energy generated is used as electricity, process steam or district heating. But the overall energy efficiency is on average only about 50 %. By using mobile heat transport, the existing plants could utilize a significantly larger proportion of the energy generated.

Biogas plants

In biogas plants, heat is generated in a CHP plant as a by-product of electricity generation. During electricity generation, about 40 % of the used energy can be converted into electricity. The rest of the energy is waste heat. Some of this energy can be used as process heat for digester heating or for nearby farm buildings. A large proportion of the waste heat, however, is often released unused into the atmosphere.

In Germany, there are more than 8,500 biogas plants. According to a survey, only around 60 % of plant operators used part of the heat externally in 2017.

For the economic operation of a biogas plant, the utilization of the accumulated heat is and will be a decisive factor. This is made possible by mobile heat transport.

More information about the use of mobile heat storage units at biogas plants you will find here. hier.

Other CHP plants

CHP plants simultaneously produce mechanical energy and usable heat. The usable heat gets disconnected when power is generated through fuel, which reduces the extraction of unused heat waste into the environment. With the help of mobile heat storage units, the heat waste can be used without the cost intensive infrastructure.

Geothermal energy

Geothermal plants are a great heat source. The heat can be charged by the mobile heat transport, without big technical changes within the plants. It’s often unclear how much heat exactly is for disposal before the drilling. When used as a temporary solution, the mobile heat storage units also allow a drastic short-term increase in heat consumption. Distant consumers, that aren’t connected to a heat network, can be supplied long-term. Plants that are generating power, can use the mobile heat transport with flexible temperatures below 100°C and use the heat. This contributes in most cases to a distinct improvement of efficiency.

Industry and trade

In many production processes emerges heat, which must be cooled down appropriately. That cooling process generates cost for the firm. The mobile heat storage units allow an economical usage of waste heat from almost all production processes. Especially for firms this is an attractive way of reducing their CO2 – emissions and reduce costs simultaneously.

In particular interesting is the mobile heat transport for firms with continuous and year-round production processes, like for example glass or paper production, foundry, chemical plants, industrial laundry or computing centre.

heat consumers

Mobile heat transport is particularly suitable for consumers with high year-round heating requirements (consumption over 700 MWh/year) and low return temperatures, such as:

Hotels, condominiums, retirement homes

Hotels, condominiums and retirement homes are due to their size often in question for the use mobile heat transport. Especially together with renovations is it economically clever, to safe the cost for a new heating system and to integrate the CO2 free heat with help of the heat storage units.

Swimming pools

Swimming pools as heat sinks are ideal for the use of mobile heat transport, as there is a high year-round demand for heat for hot water, room and pool heating. At the same time, the pool heating only requires a very low temperature level of 25 to 40 °C.

At this low temperature level, the heat accumulator is able to use its entire capacity and thus operates particularly economically. A heating solution which was previously based on fossil fuels can be completely covered by integrating the heat transport.

The indoor swimming pool in Rothrist, Switzerland, for example, has been successfully supplied with waste heat from a nearby waste incineration plant using three mobile heat storage units since 2019.


The heating of greenhouses is often looked at critical due to ecological reasons. Nevertheless, heating provides the opportunity to prolong the season for vegetables. Greenhouses are often in rural areas. At first glance there isn’t an alternative to heating with fossil fuels. With mobile heat transport, it is possible to charge waste heat from a biogas plant nearby, which otherwise would be released into the environment. Because of the low temperature levels required, it is possible to use the complete capacity of the mobile transport without cost intensive reconstruction.

Drying plants

Drying plants need continuously heat. No matter if wood-, feeds-, or sewage sludge drying, heat must be available year-round. For lack of connection to heat networks the heat gets produced trough fossil fuels. The mobile heat transport creates an ecological solution for this problem.

Following the amendment of the Fertilizer and Sewage Sludge Ordinance in 2017, the fees paid by municipal sewage treatment plants for the disposal of sewage sludge have been increasing steadily. It is necessary to cover ever longer distances to ensure the disposal of the wet and thus heavy sewage sludge. By drying, the sewage sludge loses up to 80% of its weight – and can even be used as a non-fossil fuel.

Mobile heat transport can supply the energy required for the drying process from nearby waste heat sources. As wastewater treatment plants often operate decentral without being connected to a gas network, the delivered heat represents a flexible, cost-effective and climate-friendly solution without fossil CO2.

Picture: i+M Zizmann GmbH & Co.KG
Hospitals, rehabilitation clinics

Hospitals and rehabilitation clinics require large amounts of heat year-round. Especially rehabilitation clinics with an in-house swimming pool need a lot of low temperature level heat. Ideal for the use of mobile heat transport.

Gyms, sports facilities

Gyms, and sport facilities are often tied into central heating systems with other consumers. If the heat consumption is higher than 700 MWh per year, mobile heat transport could be an interesting solution to obtain nearly CO2 – neutral heat.


Schools are often municipal organised. Here the municipal itself can get involved into integrating the mobile heat transport to improve the CO2 balance in their area.

Especially during renovations and enlargements mobile heat transport should be considered.

Heat networks for the supply of residential areas

In particular large buildings and entire groups of buildings have a year-round demand for heat, for both heating and hot water requirements.

In newly built neighbourhoods, it is possible to design a system specifically for heat transport, thus covering the entire heat supply.

This allows a modern heating network with a low temperature level to be implemented as an alternative to the classic natural gas network. The mobile heat transport system flexibly supplies the required heat in summer and winter through adapted charging cycles. The heat is generated decentral via various regional heat sources.

This heating network can be operated together with a contracting partner or by the municipality. The costs for the consumers are comparable to supply solutions based on fossil fuels.

Even in older buildings, the skilful integration of mobile heat transport makes sustainable heat supply possible as part of renovation measures. The mobile heat transport provides the CO2 – free heat as base load into the existing heating system, the peak load gets provided by the old heating system.

You want to get a first idea about using mobile heat transport for your possible heat source or consumer?
Fill out our contact form and share the power of your plant and the amount of heat per year if possible.