In the case of fourth or fifth generation local heating networks, which often are subsidized with public funds, monitoring the operation of the system is regularly a requirement of the funding decision. However, even without such an obligation, operating data from such networks is a mandatory prerequisite for sustainable operational management. System operation can often be optimized and profitability improved based on the experience gained during the first few years of operation. In the case of geothermal systems an underground energy reservoir has been tapped, the heat content of which is not inexhaustible and significantly influences the efficiency of heat pumps through its long-term temperature development.
In our experience, cold local heating networks and large geothermal systems are regularly equipped with data acquisition technology to various extent. Usually operating data such as thermal output (power), volume flow, temperatures and energy quantities are recorded. However, parameters such as measurement intervals, number and location of data points and storage duration of historical data are handled very differently, depending on the experience of the planning engineers. If geothermal systems are involved, a geothermal specialist is rarely consulted when designing the monitoring concept. Although the often unspecific requirements for “monitoring” a system are fulfilled with the acquisition of operating data, the not inconsiderable amounts of data are often not further evaluated or interpreted.
In this presentation, we will first discuss suggestions for a monitoring concept adapted to (shallow) geothermal systems. In addition, operating data from a cold local heating network with borehole heat extractors will be shown as an example and ways for both automated and specialized evaluation and interpretation will be discussed. The aim of the data evaluation is to provide operators with easily understandable key figures of the system status (similar to a traffic light), as well as in-depth analyses from which optimization of the control strategy or reference values for future system planning can be derived.
A meaningful evaluation of operating data is the necessary basis for asset management for investors in large-scale geothermal systems and innovative heating or cooling networks!