The Complex History of Geothermal Utilization for the District Heating System of Hveragerð

Abstract

The Hveragerði high-temperature geothermal field is located in SW-Iceland, close to the municipality of Hveragerði – a town with a population of about 2,500. The residents of Hveragerði have utilized the geothermal resource for house heating since the 1930’s, - at first by using the direct flow from hot springs in the vicinity of the town, followed by drilling of the first wells in the area in the 1940’s. Current district heating system includes a two-fold distribution system to supply 180°C steam and 100°C water from two 400 m and 700 m deep wells to industry, greenhouses and households. Clogging of wells and precipitation within the distribution system have caused repeated operational issues, and attempts have been made to reduce these as much as possible. Measures include installation of heat exchangers and a closed-circuit district heating system for supplying hot water to households, reaming of the precipitates within the wells on regular basis and operating certain parts of the town on separate district heating systems. Here we present the problems the district heating system of Hveragerði has been facing through its 80 years of operation and how these have been solved through repeated adjustments, redesigns and re-construction, which has resulted in the whole system being re-designed at least six times. Finally, we present the current future plans for this most complex utility found in Iceland.