We continue to optimize energy use in the older property portfolio. That's why we installed our first geothermal plant at Kämnärsrätten - and halved the property's heat consumption.
- As a property owner, you influence your environment in a variety of ways, says Staffan Jacobsson, Technical Service Manager at AF Bostäder. That's why AF Bostäder is working on sustainability issues and reducing our environmental impact, all the way from which energy we buy, to raise awareness about the sustainability of our tenants.
- The efficiency of the energy systems in the older properties has the highest priority, says Staffan Jacobsson. Since 2014 we have run a pilot project at Kämnärsrätten where we monitor and control the properties in the smallest detail. There, we have carried out a variety of technical upgrades and also implemented a web-based monitoring system. The geothermic project is another major step towards lower energy consumption.
Geothermal energy means that energy is extracted from deep boreholes in the soil's soil and rock layers. The geothermal energy can consist of heat produced by geological processes in the interior of the earth, or by stored solar heat. The heat rises the further down you drill. At ten degrees on the surface, the temperature is 40-70 degrees to two kilometers deep.
- In June 2015 we conducted a successful test drilling at Kämnärsrätten, says Staffan Jacobsson. The conditions for geothermal energy are good in many parts of Lund and the drilling showed that Kämnärsrätten was a good place for a full scale plant.
In December 2016 the plant was completed at Kämnärsrätten 2, a property with a total of 96 apartments. The plant consists of 2 heat pumps and 14 energy sources. The wells reach 250 meters deep and contain a closed pipeline that collects the energy and transports it to the system's heat pumps, where it is heated in the property's hot water system.
- We use the plant to produce heat, while hot water is still heated with district heating, says Staffan Jacobsson. We have made that choice because installed electrical power is reduced, heat pumps are most effective at low temperatures and the lower heat of the district heating in summertime is allocated to tap water.
- The plant covers virtually all of the house's heating needs, says Staffan Jacobsson. When cold, we use district heating as an extra tip, but it is plugged in at the earliest minus four degrees, and has barely been used during the first winter of the plant. Installing geothermal energy that can handle lower temperatures becomes too costly. Geo-energy is a big investment, but the savings mean that the entire plant is paid within eight years.
- The geothermal plant uses electricity only for operation of the system, while the actual heat energy we produce is free," says Staffan Jacobsson. If you compare with the electricity consumption in a standard electric boiler, you will generate at least four times the amount of heat energy from a geothermal plant. We will test and evaluate the system in the long term, but the first indications are very positive. During the first winter of operation, we have sharply reduced our heat consumption compared to the same period last year.
- The environmental impact of the system is basically zero, especially since the beginning of 2017 when all the electricity we purchase from AF Bostäder is derived from renewable production, says Staffan Jacobsson. Now the work on energy efficiency is continuing and in the future we will explore more opportunities for renewable energy sources.