The energy efficiency problematics in sports facilities: identifying savings in daily grass heating operation

Recently, reflections on modern sports stadiums' environmental impacts have gained substantial attention. Large-scale stadiums of e.g. professional soccer teams are characterized by having installations of grass heating systems serving the crucial commercial asset and at the same being the sub-system with the highest yearly thermal energy consumption. Public buildings of this size imply situation-specific operational modes combined with high levels of safety and comfort requirements. In this paper we provide a first study on the energy savings potential of a professional soccer stadium's grass heating system during day-to-day operation. In practice, limited heating capacities of the arena have to be adhered to, which causes the current operation to often result in under-performance of other, less critical facility units. Our analysis of dynamic operational and contextual data serves as foundation for long-term energy efficiency measures. We study relevant parameters related to the current control schemes and the stadium's context. Concretely, the grass root temperature as critical observable is studied with respect to weather conditions and the resulting thermal behavior. We provide an improved control strategy and quantify the anticipated savings of this strategy to be as high as 34% compared to the last heating season. For the future, the documented thermal characteristics will enable the formulation of more advanced control strategies to positively influence the grass heating operation. This will lead to further improvements in balancing the heating demand across all thermal facility sub-systems by integrating operational context with forecasts of the thermal behavior in the future.