DEVELOPMENT OF HEAT PUMPS IN NORWAY
The largest achievement in research and development for heat pump that has been carried out in Norway is in the field of heat pump systems with carbon dioxide (CO2) as working fluid. Professor Gustav Lorentzen and his co-workers at NTNU and SINTEF Energy Research developed the concepts of the "transcritical" CO2 heat pump cycle. The industrial group Norsk Hydro acquired all commercial rights to this technology in 1990. The CO2 technology developed at SINTEF has e.g. been licensed to Japanese manufactures that are producing the “Eco-cute” heat pump water heating systems for residential and commercial applications. At the Institute for Energy Technology (IFE) in Norway they have developed a unique compression/absorption heat pump system for industrial applications. The Norwegian heat pump market has been growing steadily since 2001. During the 1990s the annual sales figures were between 1000 and 2000 units/year. In 2006 the market reached 78,300 units which is an all time high. The most popular heat pump system in Norway is single unit air-to-air heat pumps. These heat pumps are replacing electric baseboard heaters and thereby reducing the dependency of electricity for space heating. In Norway there are also many medium- and large-scale heat pump systems with seawater, groundwater, rock or sewage as a heat source. One of the largest ground-source heat pump systems in the world for heating and cooling was installed in 2007 at the new hospital “Nye Ahus”. The largest heat pump system in Norway is a 28 MW sewage heat pump supplying 90ºC heat to a district heating grid. The Norwegian Water Resources and Energy Directorate (NVE) has estimated that heat pumps will contribute with 10 – 14 TWh/year renewable ambient heat in Norway by 2020 compared with about 5 TWh today.