energy requirement per plot is around 15,000 kWh, which equates to a heat output of approximately 7.5 kW. This required a total of 117 ground source heat loops in boreholes to depths of 30–40 m. 35 plots [...] the 63 mm diameter JANSEN powerwave corrugated pipe results in a larger heat-exchange pipe surface (0.22 m²/m), which allows considerably more energy to be absorbed from the ground. In parallel with this [...] powerwave single-u ground source heat loops used in Sommerach have a large storage volume of over 4.5 litres per metre of loop. More energy can be stored temporarily in this large volume of brine. This