IAlways really hot: Wherever scalding, hardening, painting and drying takes place, the equipment used radiates heat. It is usually difficult to use on site. This also applies when, as in foundries or steelworks, the waste heat generated during the metallurgical processes running here reaches significantly higher temperatures than the scalding water in a sausage kitchen. Although office and administration buildings at the respective industrial site can be brought up to temperature with steam heating in the cold season, only part of the heat generated can be used. This waste heat can only be used effectively for around 3000 hours a year. In summer the heating stays off.
It’s not much different with the heat that gas engines that run on liquid manure or silage methane release through their exhaust gases and cooling water. Ideally, it is also only suitable for heating, for example gymnasiums and swimming pools. However, since there are not enough heat sinks of this type, most of this heat is released unused into the environment. How great this potential is can only be estimated. It is assumed that the waste heat generated in Germany alone, which comes from industry and commerce, could generate 23 terawatt hours of CO2-free electricity. That would be enough to supply almost 20 percent of all German households and avoid around ten million tons of CO2.