Direct Utilization of Geothermal Water for Space Heating in Akureyri, N-Iceland

Abstract

In Akureyri. a town of 15000 inhabitants in N-Iceland, geothermal energy has replaced oil burning for space heating. Five geothermal fields at 2-13 km distance from Akureyri are exploited, each yielding 15-45 of water. In 1993 the annual energy production equalled 240. Since the systems are fracture controlled and embedded in low permeability volcanic rocks, a 200-300 draw-down is necessary to achive the desired rate. The water is pumped from the geothermal fields along insulated steel pipes to a central pumping station (CPS) in Akureyri, where it is mixed and directed to the consumers. About 30% of the supply water is collected as return water to the CPS where it I heat pumps. In addition a 12.5 oil burner is standby for emergency use. The water is very low in chemical content. An addition of is necessary to counteract a small oxygen contamination originating to the water in degassing tanks.