Experts say 2,860 terawatt hours of heat is wasted in the EU every year. That’s almost as much as Europe’s total demand for heat and hot water. Most of this excess heat could be recaptured and put to use with existing technology, such as heat pumps. This would reduce CO2 emissions, bring down energy costs and build more resilience into our energy systems. That’s according to a new study by Danish engineering firm Danfoss. Excess heat could be captured from a factory flue using a heat pump, for example, and used to provide the same factory with heat and hot water. Several European pilot projects are already in the works. For example, excess heat from Berlin’s metro system will be used to heat an office building.