Dusseldorf Factory towers and ventilation gates throw large amounts of thermal energy into the environment – at the same time, on some good days, solar and wind parks produce excess electricity that is difficult to store. In view of the federal government’s approaching climate target – greenhouse gas neutrality by 2045 – both scenarios are problematic because a lot of usable energy is lost.
Kraftblock, a start-up from Sulzbach in Saarland, now wants to put an end to the waste of energy. The approach: building block-like modules in which granules are heated that store the heat for up to two weeks. The company was founded in 2014 by chemist Martin Schichtel and economist Susanne König. Now they have landed a major order from food manufacturer Pepsico in the Netherlands, for which Kraftblock will cooperate with energy giant Eneco Gas.
Industry and households balance each other out in nationwide energy consumption. The lion’s share in both sectors is attributable to heating and cooling generation. The main sources of energy: natural gas, coal, oil. According to the Federal Environment Agency, only 16.5 percent of the heat for industry and households was generated with renewable energies in 2020.
“The heat transition hasn’t really got going yet,” says Kraftblock CEO Martin Schichtel. Regulatory hurdles and a lifeless market in Germany prompted the start-up to do its first business abroad. “In the Netherlands, we also saw a greater willingness to take risks,” explains Schichtel.
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“The top priority must be to increase the energy efficiency of industry, also by reusing heat for as long as possible,” explains Paul Münnich, project officer at the Agora Energiewende think tank Supplying heat “when the sun isn’t shining,” says Münnich. However, the Grid Fee Ordinance provides incentives to purchase electricity as evenly as possible: “That inhibits the profitability of heat storage. Instead, flexible and system-friendly power consumption must become attractive.”
Kraftblock cooperates with Eneco Gas
In many places, steaming chimneys show what happens to part of the process heat from industry: it is passed on to the environment as waste heat. That seems wasteful – and it is: Targeted use of waste heat could lower the energy requirements of industries and reduce environmental pollution, according to a study by the Fraunhofer-Gesellschaft.
This gap in the market between production and waste heat disposal is gradually being filled by various storage providers. Kraftblock is one of these companies. In the Netherlands, the start-up wants to install a high-temperature storage system in a factory belonging to the food company Pepsico. In production north of Amsterdam, the project aims to decarbonize the production of potato chips.
The start-up Kraftblock stores energy in the form of heat in such containers. It is produced from solar power, for example.
(Photo: Kraftblock)
“We are working on the project with our Net Zero Heat system,” explains the CEO to the Handelsblatt. This means that the Eneco Group supplies green electricity from wind turbines, which is converted into thermal energy according to the so-called power-to-heat principle (“energy to heat”) and stored in the thermal modules from Kraftblock. Two of these modules, each with a capacity of 35 megawatt hours, are to be installed by the end of 2023, with three more to follow.
With the process heat storage, Kraftblock wants to replace the gas boilers that the chips factory uses to heat the frying oil. The first two modules should save 4.5 million cubic meters of gas annually.
The comparison shows that this large number is still rather small on an industrial scale: the chemical industry in Germany alone consumes almost seven billion cubic meters of natural gas every year, the food industry needs almost half.
Modules convert electricity into hot air
According to the company, this will result in the largest commercial storage facility of this type. CEO Schichtel explains the structure of the system: “We work modularly, which means that the storage units and the loading and unloading stations can be adapted to the circumstances of production – the ‘Lego ‘ principle fits very well as a comparison.”
Kraftblock uses separate modules to store and withdraw the thermal energy. During loading, hot air is pumped into the accumulator and heats up the storage mass, a granulate, inside. The discharge occurs in a similar way: colder air is blown through the carrier medium, heats up and escapes as usable thermal energy.
Other companies such as Siemens Gamesa also work according to this concept. The lava stones from the Siemens Energy subsidiary can be heated up to 800 degrees Celsius.
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The granules in the Kraftblock modules can reach temperatures of 1300 degrees Celsius, explains Schichtel. A flexible control between room temperature and extreme heat makes the system attractive for various industries: from food production to plastic or glass processing. In the past few years, Kraftblock has already aroused the interest of the Dutch entrepreneur and co-founder of the travel portal Booking, Kees Koolen, and the investor Frank Thelen.
Kraftblock wants to transport heat by truck
“The division of the system into different modules has the advantage that the heat storage tanks can be transported flexibly,” says Schichtel. His vision: Heat as a classic transport good. “This also opens up new business models for logistics companies,” says the CEO. In a first project, heat generated during the gas flaring process in a steel works is to be transported to the Kraftblock factory in Sulzbach in order to heat the production halls there.
The heat stays in the storage modules for up to a week during transport, and up to two weeks in stationary projects. “At some point,” says Schichtel, “the technology will of course reach the tipping point between the insulating mass and the storage capacity.”
However, Münnich sees the transport model as proof of “the misguided regulatory incentives that are being set here. The aim must be to quickly expand electricity and heating networks as well as flexible consumers – such as heat storage tanks – and to encourage energy consumption that is beneficial to the system.”
More: The world’s largest battery storage system is being built in southern Germany.