With heat pumps, 1 = 5: one unit of renewable electricity can produce up to five units of clean heat
According to the Heat Roadmap Europe 2050 study funded by the European Union, industrial processes in Finland annually generate more than 20 TWh of waste heat, which is equivalent to the energy amount of the coal used in Finland.
In terms of heat production efficiency, heat pumps are in a class of their own. When using one unit of electricity, they can produce 3–5 units of heat – and, often, cooling at the same time. So it clearly goes without saying that heat pumps are an excellent way to reduce emissions in the heating sector, cost-efficiently. The industrial-scale heat pump plants connected to a district heating network are especially efficient.
However, it wasn’t too long ago when using electric heating was considered a fundamentally bad solution because electric energy was considered a more valuable energy than thermal energy. Unlike electricity, heat has an unfortunate way of dissipating. But utilising this waste heat has become easier, thanks to recent development in heat pumps.
By employing the properties of the refrigerants flowing in heat pumps, waste heat (e.g. at a temperature of 20–30 degrees) can be recovered and its temperature significantly increased (e.g. to 50–90 degrees). In order to do this successfully, heat pump needs a preferably steady heat source, like the heat from, say, warm shower water and toilet wastewater from households, the heat generated by computers in data centres, or the heat generated in industrial processes.