Hütt Brewery

This brewery in Kassel (Germany) has integrated a solar heat system for the brewing process which began operation in May 2010. The solar thermal system consists of 155 m2 flat-plate collectors which generate part of the thermal energy required for supplying hot water to a maximum of 90°C. The energy transfer medium is a mixture of water-glycol and the water is heated via an external plate heat exchanger. The temperature range solar loop is up to 95oC, and the temperature range process from 40 to 90oC. The energy is transferred to a 10 m³ buffer storage tank. The annual useful solar heat delivery is 400 MWh/year.

The solar-heated brewing water is then fed into the drawdown tank when its fill level drops below a certain level. However, it can only be filled to 80% of its capacity; since this storage tank is additionally filled with hot water produced using heat recovered during the wort cooling process. Corresponding volumes are kept free during the production times from Sunday evening to Friday noon. The drawdown tank releases hot water to the displacement tank and also supplies the mashing process, which only requires relatively low temperatures of just under 60 °C. During production free periods, the drawdown tank is completely filled with solar heated brewing water. The conventional heat source is a steam boiler (BINE, 2010).