Power-to-gas system wins award

In collaboration with a total of eight Swiss energy suppliers and the municipal utility alliance Swisspower, Limeco has been operating the first power-to-gas plant on an industrial scale since last year. This plant has now received the renowned Watt d’Or.

The new multi-energy hub that will continue to supply the Limmat Valley with sustainable energy in the future. Source: Limeco

Limeco recycles regional waste and purifies the wastewater in the Limmattal valley – and it does so sustainably. At its plants, Limeco produces CO₂-neutral heat (district heating) as well as cooling, renewable electricity and green gas. This is clean energy that benefits people and companies throughout the Limmattal valley: in this way, Limeco contributes significantly to the energy transition and the climate turnaround. At a time when dependence on gas imports is painfully evident, Swiss domestic production of renewable gas is gaining in importance. From the point of view of the gas industry, it is particularly interesting to note that the existing gas infrastructure can be used at least in part for synthetic gases, even though gas consumption is set to fall sharply if the net zero CO₂ emissions target is to be achieved by 2050.

The three models show how Limeco’s renovated energy hub – logically also with a power-to-gas plant – should look one day according to the ideas of the architecture team. Source: Limeco

Limeco has been operating Switzerland’s first ever power-to-gas plant on an industrial scale since April 2022. It has an electrolysis capacity of 2.5 megawatts and is able to produce 450 cubic meters of hydrogen per hour. This provides up to 18,000 megawatt hours of synthetic renewable gas per year, which is fed into the local gas grid. The pioneering plant seeks to contribute to the professional development and cost optimisation of power-to-gas technology in the Swiss energy system – and it is now the recipient of one of the renowned energy prizes awarded for the 16th time by the Swiss Federal Office of Energy, namely the Watt d’Or.

The plant is excellently located, which has helped make it a veritable energy hub. The waste recycling plant converts the energy contained in the waste into heat and renewable electricity. This current then breaks down water into oxygen and hydrogen in the electrolyser. The latter is converted into renewable methane gas by means of primordial bacteria, so-called archaea, which originate from the sludge in the sewage treatment plant, and also CO₂ from the sewage gas. Waste and sewage are quickly converted into energy that is valuable and in particular recyclable.

Daniela Decurtins, Director at the Swiss Gas Industry Association, presents the Watt d’Or 2023 to Limeco Managing Director Patrik Feusi and Thomas Di Lorenzo, Head of Wastewater Management at Limeco. Source: SFOE

Schmack Biogas GmbH (plant construction) and Microb Energy GmbH (processes) were responsible for the technical implementation of the 14-million-franc plant. The system is stable and has full production capability. But right now it is in a state of standstill! “The purpose of the plant is to convert excess electricity into energy that can be stored for the winter. But a lot of full-load hours would be required for this to be economically viable,” explains Thomas Di Lorenzo, Head of Wastewater Management at Limeco. Managing Director of Limeco Patrik Feusi adds: “Given the current situation, it really isn’t acceptable to turn scarce electricity – mainly produced in Europe from coal and natural gas – into biogas. That’s why the plant is now in hibernation, and it may remain so in future winters, too.” Nevertheless, plans for the future are under consideration. One option is to build a storage facility for the hydrogen for example, or if the plant is flexible enough, to use it as part of Swissgrid’s balancing reserve.

As such, the project that has received the Swiss energy prize Watt d’Or 2023 from the Swiss Federal Office of Energy also demonstrates just how tough the framework conditions can be for innovative projects at the moment. Politicians urgently need to work to finally establish a clear regulatory policy for the expansion of biogas production, for example: only then will it be possible to introduce a swift, technology-neutral approach to the climate turnaround in Switzerland. (pd/jas, 17 January 2023)

Patrik Feusi, Managing Director Limeco (left), and Luca Talarico, Manager Marketing & Communication Limeco. Source: SFOE

The other winners of the Watt d’Or 2023

Smart and sunny community: A ground-breaking three-year pilot project has been completed in Lugaggia TI, a little village not far from Lugano. It successfully demonstrated that an intelligently networked and controlled alliance of electricity consumers and solar power producers can significantly increase the degree of self-sufficiency.

Swiss solar aesthetics for the future: One of the pioneers from the heyday of the Swiss solar age is 3S Swiss Solar Solutions AG in Gwatt near Thun (BE). For over 20 years, it has been producing the highly aesthetic “MegaSlate” solar modules for building-integrated photovoltaics.

The future of electromobility – made in Switzerland: For 12 years now, EVTEC has been successfully involved in the charging infrastructure business for electric cars. At its site in Kriens-Obernau (LU), it develops and manufactures charging technologies to meet all needs. The latest innovation is the bidirectional “Sospeso&charge due” charging station with an output of 20 kW: this enables two vehicles to be charged at the same time.

Solskin gets solar facade moving: A mosaic-like structure has been on display on the facade of Empa’s NEST innovation building in Dübendorf ZH since early 2022. This is the adaptive solar facade developed by the Chair of Architecture and Building Systems at ETH Zurich under Professor Arno Schlüter. Thanks to an intelligent control system, the movable and lightweight solar modules automatically follow the path of the sun throughout the day, thereby optimising electricity yield.

Sunny career prospects with Refugees Go Solar+: This programme builds a bridge between the booming Swiss solar industry and the numerous refugees who would like to work but are not allowed to do so since they lack professional qualifications that recognised in this country. It was initiated by the two Bernese non-governmental organisations Solafrica and Root & Branch. Programme sponsors include the Swissolar Association, EnergieSchweiz and the State Secretariat for Migration.