Decentralized fuel-cell systems will make the internet more sustainable
Global demand for electricity continues to grow unabated. At the same time, humanity is facing a mammoth challenge in the shape of climate change. What is urgently required, therefore, are technologies for tomorrow that are compatible with today’s industrial landscape. In a pilot project, Deutsche Telekom is now trialing two stationary solid oxide fuel-cell (SOFC) systems from Bosch. These can be used to generate — efficiently, sustainably and in a decentralized way — the electricity required to power, for example, the operating centers for network systems.
Bosch’s operations relating to the industrialization and preparation for production of decentralized power-supply systems based on solid-oxide fuel cells (SOFC) were discontinued. Work to explore the possibilities of solid-oxide technology will continue within the company’s corporate research unit. Over the past ten years, Bosch has worked with partners to develop solid-oxide fuel-cell technology for decentralized power-supply systems. The achieved level of technical maturity has been demonstrated in over 100 pilot systems. The findings from the operation of the pilot systems are incorporated into the research activities.
The internet: a major energy consumer
Surfing, streaming, hanging out on social media — for billions of people around the world, the internet has become a fixture of everyday life. If the internet were a country, it would have come sixth in a 2019 ranking of the world’s largest energy consumers by state, according to a study by think tank The Shift Project. In a bid to become more sustainable, many internet providers are therefore shifting to electricity from renewable sources such as wind and solar. Yet both of these depend on the weather and are, as such, subject to variation. “For a telecommunications company, it’s vital to have a stable source of power. We can’t afford an outage for even a second,” says Bernd Schulte-Sprenger, managing director of Power and Air Condition Solution Management GmbH (PASM), a Deutsche Telekom subsidiary. His 140-strong workforce ensures that the parent’s “core sites” — the centers used to operate network systems — receive a constant supply of power and are therefore able to provide the company’s 48.5 million mobile customers with continuous mobile and internet services.
Hydrogen as a future source of power
In its search for new forms of power supply, PASM is now trialing a pioneering technology at a Deutsche Telekom core site in Berlin. Here, two stationary solid oxide fuel-cell systems from Bosch were installed in February 2022. They utilize an electrochemical process to generate electrical energy from natural gas or biomethane, optionally with an admixture of hydrogen. This reaction also produces heat. When, in the future, an SOFC is fueled with green hydrogen (i.e., hydrogen produced with electricity generated from renewable energy), the power and heat produced will be completely carbon free.
Thermal energy from the reaction can be used for heating or cooling
The futuristic-looking SOFC unit houses several hundred fuel cells. These are piled into stacks, which constitute the engine of the electrochemical process. Each SOFC unit generates around ten kilowatts (kW) of electricity and around 3 kW of heat. Over the course of a year, this amounts to some 80,000 kilowatt-hours (kWh) of electricity — potentially enough to cover the annual power needs of 20 or more four-person households. This process also produces thermal energy, which can be utilized either to heat buildings or to produce — by means of an absorption chiller — chilled water with which to cool servers.
Highly efficient and fuel-flexible
The fuel cells achieve an electrical efficiency of 60 percent. Furthermore, SOFC systems are very versatile when it comes to the choice of energy carrier. In the Berlin pilot project, PASM is currently using natural gas, as there is no local hydrogen infrastructure in place. In the long term, the conversion of such systems to more sustainable energy sources is possible. Even when running on natural gas, the SOFC is considerably more environmentally friendly than some other forms of power generation: carbon emissions are around two-thirds lower than coal-fired generation in Germany, and virtually no nitrogen oxide or particulate emissions are produced. In the event that the SOFC systems are operated with sustainably produced hydrogen, carbon emissions would be completely eliminated.
How does power generation work in a solid oxide fuel cell?
Avoiding grid losses
This is by no means Deutsche Telekom’s first foray into the field of sustainable power. Indeed, its several hundred core sites in Germany already operate exclusively on renewable energy. Furthermore, the company has a stake in a number of wind and solar parks. Yet Deutsche Telekom plans to go the extra mile here — and innovations like the SOFC could well provide the key. When electricity is transmitted via cable and the overhead power lines of the public grid, there are inevitably some losses. However, by using decentralized fuel-cell systems from Bosch, PASM can generate electricity precisely where it’s needed. “SOFC technology enables us to eliminate grid losses,” Schulte-Sprenger explains. “And by using the heat that is also generated, we can boost overall energy efficiency at individual locations.” What’s more, by generating its own power, Deutsche Telekom also avoids having to pay grid fees, thereby reducing its costs. “Such innovations point the way forward, both for us as a company and for society as a whole,” he emphasizes.
