Geothermal district heating in Davos
Overview
The municipality of Davos is aiming to produce all of its energy by itself by 2036 and geothermal energy plays a central role in becoming increasingly independent of fossil fuels. Since 2010, the large geothermal reservoir under Davos has been gradually explored and developed with two geothermal heating networks already in operation and further networks to follow in the next few years.
After successful exploration drillings, in 2018, the first geothermal source was integrated into the existing heating grid that connects, among others, the congress centre, the buildings around the central Arkaden square and the ice rink. The waste heat from the ice rink is used to heat up the water circulating in the network. To achieve the necessary final temperature of 60-80 °C, heat pumps are used in addition. The fossil fuel boiler previously used for the heating network is only in operation during peak periods.
In 2020, a further heating grid was developed in the mostly residential area of Bünda. In total, 430 000 litres of oil and 1300 tons of CO2 are saved each year since the integration of geothermal in the two district heating networks. Encouraged by this success, the local utility, Elektrizitätswerk Davos AG (EWD AG) is already planning the next system in Davos.
Summary
Water temperature: 12°C
Drilling depth: 452 m
Geothermal heat pump: 880 kW
Annual heat production including heat pump (2019): 553,632 kWh
CO2 emissions saving: 1,300 tons per year
Investment: 5 million Swiss Franc