Geothermal Heating and Cooling from Ground Water Pumping Wells

NO-2004-010 Project Start date: 1st November 2003 Date last verified: 21st March 2005 Type of Project: Result Country: Norway Location: Sande municipality, south of Oslo, Norway Summary The main project goal was to implement a geothermal energy system for a 6,000 m2 building project. The building encompassed a nursing home, a service centre and 16 apartments for elderly people. Early planning has been an important success factor, combined with thorough ground investigations, water quality tests and capacity tests of the two production wells. Usually a closed collector system is chosen for geothermal energy projects, but in this case an open system was preferable as there was a large supply of available ground water in the 300 meters deep wells. A 180 kW heat pump for base load was chosen, with two oil boilers (100 + 200 kW) installed for peak load. The alternative to geothermal energy would be oil (100%) for base load, and electricity (60%) for peak load. In addition to this, cooling devices must have been installed. Aims To ensure low energy costs for heating and cooling. Summary of Results Energy production (from heat pump: 520,000 kWh/year - Energy saved 370,000 kWh/year (includes savings on cooling) - CO2 savings: 1,040 kg CO2/year Planning Issues Extensive bedrock and water analysis studies were undergone to detect the amount of iron and manganese in the ground, which cause problems for the heat exchanger. Another planning issue was to find a special solution for the wells to ensure optimal operating conditions. Financing A direct contribution came from the Sande municipality.