Borehole Energy Storage in Katowice
Overview
In Katowice, the manufacturer of metal cutting tools Sandvik Coromant has upgraded its energy system with a borehole thermal energy storage to expand the factory’s energy savings. The solution was developed by the Danish company Energy Machines that had already implemented an integrated energy system in the factory five years earlier decreasing electricity usage by 24% and natural gas usage by 40%.
The geothermal energy storage finalised in late 2023 complements the existing system with an underground thermal energy reservoir to further minimise the production site’s energy use. It consists of 33, 140m deep boreholes which were drilled next to the building. After integrating the storage in Sandvik’s energy system, gas consumption went down further, by 90% compared to pre 2019 levels, and electricity consumption to 25-30% below the initial level.
The integrated energy system was completed in 2019 replacing individual chillers for each machine with a central chiller combined with a heat pump. The same system is used for cooling of the factory building in summer. The waste heat from these cooling processes is used for domestic hot water and heating in the offices. Before the installation of the underground thermal storage excess heat was directed outside, but since the expansion of the system it can be stored in the ground around the boreholes during summer and extracted for heating during winter months. The gas boiler installed as a backup for especially cold days only had to be switched on very rarely during the first winter (2023/24) even when outside temperatures dropped to -10ᵒC and below.