Heat Pumps for District Heating [23]

District Heating in our modern world is through a transition from a governmental utility for public housing estates to a more efficient way of residential comfort by bundling the varying demand of plenty of household to balance a stable supply. At the same time it is a step forward towards a sustainable form of comfort by using a mix of energy forms like bio-mass with combustion, heat pumps using electricity generated by water/wind, geo-thermal and solar-thermal energy thus contributing towards mitigation of climate change.  
Heat pumps converting “green” electrical energy with high COP (= Coefficient of Performance) into heating using a natural refrigerant like R 717 (ammonia) which has no Global Warming Potential upon being released into the atmosphere can also be very cost effective when the needed electricity is generated in countries where hydro-generation is available in abundance.
Energy contracting has become a business of private investors where projects are realized only after a pre-sale of heating contracts of approx. 60 % of the to-be-installed capacity has been successful.
Heat pumps operated by industrial screw compressors with their known reliability and longevity at lowest service and maintenance cost are the perfect match to those long-term contracts.
Refrigerants like R 717 (ammonia), being natural and with their long-known properties, make these investments future-proof.
Decentralization and a mix of heating solutions with their redundancies for reliable supply require medium capacities between 1 and 5 MW for heatpumps.