A brewery makes itself independent of gas

The uncertain gas supply situation in 2022 set another energy building block in motion at Bergquell Brauerei Löbau in eastern Germany and subsequently triggered bold conversions. The company had long been a model company in terms of energy efficiency and was up to date with the technical possibilities. When the risk of a possible gas shortage with the threat of a supply stop for the brewery was difficult to assess, the owner took action without further ado: Steffen Dittmar brought Steinecker's energy consulting team into his company. With a great deal of creativity and commitment from both sides, the company became independent of gas as the sole basis for heat generation within just a few months and not only reduced its heat consumption once again, but above all also the heat flow peaks to record-breaking low figures.

It was by no means surprising that the brewery chose this path, as tradition and state-of-the-art technology go hand in hand at Bergquell Brauerei Löbau. Founded in 1846 and run as a regional brewery with a low output until the mid-1990s, the company from Saxony has since transformed itself into a speciality brewery that delivers throughout Germany. In addition to classic beers such as Bergquell Pilsener and Helles, Bergquell is known above all for its innovative beer creations, such as the Lusatian Porter and the Cherry and Strawberry Porter. They are brewed using regional ingredients and traditional methods. At home in Upper Lusatia, the company's own horse-drawn carriage delivers beer barrels and at festivals, beer is served from specially converted Trabants in the company livery.

Behind all the folklore, however, lies an ultra-modern business with a strong focus on quality, energy efficiency and sustainability. The beer is bottled in returnable bottles from the reusable bottle pool, purchased regionally, photovoltaic systems are installed on the roofs and process water comes from the brewery's own well. In 2008, Steffen Dittmar installed a new brewhouse from Steinecker, bringing the brewery up to the latest technical and energy standards at the time. Nevertheless, he did not hesitate when Steinecker was looking for a pilot customer for its newly developed EquiTherm system in 2010. The concept heats the mash tun with excess heat from the wort cooling system and enables the better integration of an existing vapour condenser, so that energy consumption in the brewhouse can often be reduced by 30 to 50 percent. “This not only reduces overall heat consumption, but above all we also reduce energy peaks, which greatly relieves the boiler house,“ explains Helmut Kammerloher from the Product Development department at Steinecker. He was already looking after Bergquell at the time and remembers: “The decision to upgrade the brewhouse, which was only two years ‘old’, was a remarkable one.“ But Steffen Dittmar quickly felt vindicated by the savings: “Our trust in Steinecker has paid off.“

His courage has also been publicly recognised, for example with the ‘Best Practice Energy Efficiency’ label 2013 from the German Energy Agency Dena and the Saxon Commercial Energy Passport 2011. Steinecker has also been recognised for his EquiTherm and received the main award of the Bavarian Energy Prize in 2012; and the patent-protected invention has been included in textbooks.

The initial situation

Thanks to its earlier investments, Bergquell Brauerei Löbau was actually well equipped when it threatened to run out of a secure gas supply in 2022. “The primary energy consumption of the entire brewery, including bottling, was around 26 kilowatt hours HS ( calorific value) per hectolitre of beer, which was significantly better than in other breweries of this size,“ says Kammerloher, adding: “And that was with traditional brewing processes, i.e. without high gravity.“ However, should a supply stop really come, even his business would not be immune, Steffen Dittmar explained to the Sächsische Zeitung at the time: “If gas becomes scarce, breweries are not systemically relevant. Then the beer in the tank spoils because it can no longer be bottled, so even an announcement two to three weeks in advance won't help."

In order to become more independent in this respect, Dittmar contacted Steinecker at the time - and set a challenging task: a way had to be found to provide the heat flow for the main steam consumers, wort boiling and bottle washing machine, as well as the smaller consumers, such as flash pasteuriser, KEG and CIP, without natural gas as an energy source. In addition, two extremely different steam supply lines are installed, one with 1 bar and one with 7 bar supply pressure.

Thanks to EquiTherm, the third large consumer, the mash tun, was already supplied recuperatively with the excess heat from the wort cooling system and no longer placed a load on the boiler house.

Step by step to the solution

The first step was an energy consultation by Steinecker, which scrutinised the entire operation as closely as possible, determined the energy requirements of all processes - i.e. in addition to wort boiling, mashing and bottle cleaning, also post-heating processes, CIP cleaning, flash pasteurisation and keg filling - and quantified heat peaks over time. The fundamental question was: What needs how much heat and when?

Then it had to be clarified: Where can how much heat be saved or fed back into the system? Is it possible to safely reduce energy peaks in such a way that the large steam boiler can be switched off without restricting the production process? These were the prerequisites for retrofitting a dual-fuel burner to the small boiler in order to be able to maintain production with heating oil in an emergency.

The solution lay on the one hand with master brewer Guido Sattelmaier, who, together with his team, put his heart and soul into optimising the processes in the brewhouse and the bottling plant, and on the other hand in reducing losses. However, the first decisive building block was an additional, extensive recuperation of waste heat.The second important component was the implementation of an energy pressure accumulator, which buffers energy peaks and thus enables the supply from the small steam boiler. An existing cylindroconical tank was converted into a storage tank, which is now reheated from the steam boiler whenever it is not being operated at nominal load. This energy storage tank now supplies the bottle washer and serves the brewery's hot water reheating system at certain times, so that the only peak consumer is the wort boiling system, which is directly connected to the steam boiler.

In theory, it's all relatively simple, but it had to be done quickly and the small steam boiler had no reserves in terms of simulation technology. That was new territory. Helmut KammerloherProduct Development at Steinecker

It turned out that the steam boiler quickly started to ‘sweat’ and pumped steam with too much condensate if control processes were not started up and shut down vigorously. At this point, the Botec process control system from Steinecker and its experienced programmer provided the key to success. Thanks to the internal possibilities, a parameter-dependent module was quickly designed that prevented boiling delay in the steam boiler and thus enabled a very constant mode of operation - similar to a combined heat and power plant that always wants to be operated at nominal load. In addition, signals from an older external machine could be read out and utilised in Botec.

The result is impressive

Today, the brewery is supplied exclusively by the small steam boiler, which produces a maximum of one tonne of steam per hour at an average boiler pressure of 5.5 BarG (that's around 580 kilowatts). As the brewery now produces 1,350 hectolitres of cold wort per day in the peak season (and bottles corresponding quantities), it achieves a record-breaking low specific boiler output of just 430 watts per hectolitre. Everything is included in this heat flow: Brewhouse, bottle cleaning, flash pasteurisation system, keg filling, CIP cleaning, reheating processes and more. “Even highly efficient large breweries often only achieve a specific boiler output of 1.5 kilowatts per hectolitre and smaller breweries with an annual output of up to 100,000 hectolitres sometimes even achieve 3.5 kilowatts per hectolitre of installed boiler output,“ says Kammerloher.

Brewery owner Dittmar is also satisfied: “Our expectations have been met and we have been able to realise savings since the first day of the changeover. I would like to thank the many hard-working employees at Steinecker and my brewery team, without whose co-operation there would have been no success. To be honest, I'm already looking forward to future innovations, I'm sure Steinecker already has something in the drawer“. Take courage, we are ready!“

The brewery has gained scope for the realisation of new ideas thanks to the renovation. After all, lavishly equipped and cost-intensive boiler houses have both a high CapEx and OpEx* because oversized systems have much higher energy losses. In contrast, the extremely low specific boiler output at Bergquell Brauerei Löbau has several very positive effects.

Firstly, it significantly reduces boiler losses and also results in lower maintenance, TÜV and electrical costs. Another interesting aspect is the reduced connected load at the supplier, as relatively high charges can be incurred for providing the maximum natural gas flow. And, of course, fewer obligatory reserves give a company more scope for investment in future projects.

One such project could be the implementation of a heat pump, which can be designed to be particularly lean and to the point for such an optimised brewery. The uniform operation of such a system also avoids incalculably high electrical peak costs, which are charged by the electricity supplier or grid operator and often drive up the price of electricity in many countries. Thanks to a centralised energy storage system, system-relevant control functions could even be assumed in principle or dynamic electricity tariffs could be used, which, incidentally, will be mandatory for every supplier in Germany from 2025. “Our expectations have been met and since the first day of the changeover we have also been able to achieve savings that will probably reach around 700,000 kWh after a whole year,“ explains Steffen Dittmar.

* CapEx: Capital Expenditures, OpEx: Operational Expenditures