Groundbreaking ceremony heralds official start of construction of an innovative total energy concept in Stein near Nuremberg

Source: Energy & Management Powernews, February 21, 2022

In Stein near Nuremberg, the groundbreaking ceremony for an innovative CHP plant took place. To the official start of construction, Bavaria's Minister of Economic Affairs and Energy Hubert Aiwanger had also arrived.

"We are now playing in the energy national league," Kurt Krömer, mayor of the city of Stein near Nuremberg, had cheered in January 2020. Shortly before, Stadtwerke Stein had been awarded the contract for an iKWK system. Thus the existing local heating net in the local part Deutenbach should be brought on a current, still more climaticcareful conditions and save in relation to now over 4,000 tons CO2 annually.

Almost exactly two years later took place on 17 February the cut of the spade for the innovative warmth and current production - with Bavaria's Minister of economics and energy Hubert Aiwanger (free voters). He praised Stein for being "on the way to being self-sufficient in energy as far as possible". And: the Free State had created with the promotion of the overall energy concept for the municipality the conditions to develop a project eligible for funding according to the conditions of the iKWK tender. 

f. l.: Matthias Dießl (District Administrator of Fürth County), Kurt Krömer (First Mayor of Stein), Hubert Aiwanger (Bavarian Minister of Economic Affairs), René Lukas (Managing Director of Stadtwerke Stein), Prof. Markus Brautsch (Head of the Institute for Energy Technology at Amberg-Weiden Technical University), Günther Hein (Managing Director of AGO GmbH). (Photo credit: Stadtwerke Stein)

For the Minister, the municipalities are "the central players in the ecological energy transition." Therefore it advertised itself for the fact that other smaller cities - stone has straight times 14,000 inhabitants - the neighbouring municipality of Nuremberg to the model take and likewise a promoted energy concept compile let. 

For the Steiner energy concept the Institut for energy engineering IfE of the technical university TH Amberg Weiden had been responsible. In it, the team around IfE head Professor Markus Brautsch had proposed as a "preferred variant" the "transformation" of the local heating network "towards an iKWK system." 

This will - as required for iKWK - essentially consist of three elements: 

• A CHP unit supplied with natural gas with a maximum of 3,500 annual full load hours produces 1,999 kWel and 2,100 kWth. It generates heat primarily in winter. During this time, the flow temperature in the heat network is about 90° C.
• In the summer, the air-water heat pump is mainly used. It produces from a power input of 285 kWel a heat output of 850 kW and counts as a "renewable heat generator". 
• A power-to-heat system including heat storage converts 800 kWel in 800 kWth at wind power surplus. 

The local heating network in Stein exists since the 1970s. At the groundbreaking ceremony directly at the heating center Deutenbach lay on an open area still three huge oil tanks in the already dug up ground: Up to 2004 still oil boilers, afterwards three gas boilers in the heating house produced the warmth for the former new housing estate in the northwest of the city: The last ones will serve in the future the peak load. 

On this free surface, under which so far the oil tanks lay, now the building for the new gas BHKW is established. According to Stadtwerke boss Rene Lukas, it will be "H2-ready" - that is, at some point it will be powered by "green hydrogen." 

Since the heating center is located in the direct vicinity of a high-rise building, a different location was chosen for the rather noisy heat pump: next to the gymnasium of the local elementary school center, as Lukas emphasizes. The fact that the early "integration of the residents" and partial modification of the construction plans has shown its effect also proves "that we can now build without lawyers and courts." 

Building - this will not be done by the municipal utility itself, but by the Kulmbach company Ago Energie und Anlagen GmbH as general contractor. Ago managing director Günther Hein refers among other things to experience with other iKWK projects, for example with the system of the public utilities Lemgo (North Rhine-Westphalia), which is likewise under construction and had received in the same advertisement the addition of the federal net agency. Hein named the commissioning date in Stein as the end of September. 

For the TH Amberg-Weiden, the iKWK system in Stein will already become "a real laboratory during commissioning, which we will accompany scientifically, because it is not an off-the-shelf project. But the decarbonization of existing housing is an important topic," emphasizes Professor Brautsch. 

Author: Heinz Wraneschitz