Germany's first heatable hockey pitch with synthetic turf from Polytan was completed in Grünwald leisure park in October 2015. Half of the regenerative heating energy required comes from the "return flow of the return flow" of a geothermal power plant in Laufzorn, which has been supplying the Grünwald district with thermal water at a temperature of 120 °C since 2011. The choice of pitch was made in favour of Poligras Mega CoolPlus, an unfilled professional hockey turf from Polytan whose compact and even surface is conducive to fast and accurate play. The heating system beneath the synthetic turf comes from AST Eis- u. Solartechnik. A brine-conducted heating system has been installed and functions extremely efficiently owing to its low flow temperature (approx. 24°C), quick response times and a 50% reduction in thermal heat loss. The high efficiency can be attributed to the AST heating mats, which are located directly underneath the elastic layer. Similar commercially available piping systems are located around 100 mm deeper in the ground and therefore have considerably higher heat losses.