This brewery in Eichstätt is another case of integrating solar energy with process heat. In 2009 it installed a 735 m² solar collector surface area with compound parabolic concentrator (CPC) vacuum tube collectors and two patented 5.5 m3 SLS® stratification buffer tanks connected in series. The system described heats the water up to 130oC.
The system supplies energy to various process stages that requires temperatures of up to 100°C (bottle cleaning, preheating of domestic and process water, and building heating) depending on the maximum water temperature reached in the storage tank. Once the water temperature in the storage tank reaches 110oC, hot water is first used to heat water to 90°C via heat exchanger for the bottle washer, later for domestic hot water at a range of 60-90°C and finally, if required, to space heating in a range 45-65°C. However, when temperature reached is between 50-80°C, then it is used only for heating domestic hot water.
The Hofmühl Brewery brews twice as much beer during the summer months, when more solar energy is available, than in winter. Furthermore, the Hofmühl Brewery has not installed large storage tanks given that most process stages are conducted at a relatively low temperature and the heat requirement is distributed fairly consistently throughout the day and week (BINE, 2010).
- BINE. 2010. Brewing beer with solar heat. [pdf] Publisher: FIZ Karlsruhe 76344 Eggenstein-Leopoldshafen, Germany. Available at: http://www.bine.info/fileadmin/content/Publikationen/Englische_Infos/projekt_1310_engl_internetx.pdf Accessed October 2013