Energy and Resource Reports
For years, energy consumption and costs at the university have been recorded. This recording has become increasingly detailed and automated over time, and the data is subsequently analyzed. Energy-saving potential is identified from this data, and the success of implemented measures is demonstrated. For several years now, an annual energy and resource report has been compiled and published. Download the current 2021 energy and resource report now (PDF, 4.6 MB) .
Energy management
The energy management system at THM was designed to record the consumption of each individual building. This is by no means standard practice. Often, properties are only monitored via the utility companies' billing meters. For example, until about six years ago, Campus A in Giessen had only one district heating meter for several buildings. Now, each THM building is recorded individually, unless the buildings are so closely interconnected that individual metering is impossible. This is the case, for example, with buildings A1-A4 in Friedberg. Strictly speaking, these are not multiple buildings, but rather a single building that has been continuously expanded over its lifetime.
To illustrate the energy flow, a meter matrix has been created for all properties. The following example from Friedberg shows that natural gas is supplied from the left (yellow), converted into heat by the boiler system or the combined heat and power plant, and then pumped into the respective buildings.
(Click image to enlarge)
The energy management software now allows for the input of meter dependencies, such as between main and submeters. In Friedberg, this enables the determination and continuous monitoring of the annual efficiency of heat generation. Losses across the distribution network can be clearly identified. Individual buildings can be compared using specific consumption figures, such as kWh/m².
Meter readings are largely automated, allowing consumption data to be displayed every 15 minutes. This detailed breakdown enables a very precise representation and analysis of building consumption profiles. This information is used, among other things, to identify potential energy savings and to thoroughly assess the economic viability of photovoltaic systems. For example, in 2018, the high base load electricity consumption in building A10 was noticed. As a result, the ventilation system was optimized and operating times were adjusted to match occupancy.
The hourly consumption figures can be compared with the potential yield of a PV system, and the self-consumption of the self-generated electricity can be estimated very well.
As the following graphic shows, the successes of using such software can be clearly illustrated. Thanks to the new photovoltaic system on the A5 motorway, significantly less electricity had to be purchased from the energy supplier during daylight hours than in the previous year (gray shaded columns), as part of the demand could be met on-site. (Click image to enlarge)
Another major advantage of energy management software is the timely detection of excessive consumption. Unusual consumption patterns generate a warning message, allowing the cause to be investigated and corrective action to be taken quickly.
Implementation of an energy monitoring system in Friedberg
At the Friedberg campus, an energy monitoring system was implemented, similar to the one in Giessen . This system is crucial for analyzing energy consumption and developing energy-saving measures. The goal is to create a basis for cost-benefit analyses, energy-efficient renovations, invoice audits, and visualizations of load profiles to identify potential energy savings at the Friedberg campus.
The energy for heating on the Friedberg campus is supplied by two boilers and a combined heat and power (CHP) unit. The CHP unit was already equipped with a gas flow meter and a corresponding heat meter. This was not the case for the two boilers.
To objectively assess the efficiency of each boiler for energy monitoring, it was necessary to install one gas meter and one heat meter per boiler. This was successfully implemented in autumn 2018. The data connection (M-Bus connection) of the meters was also ensured.
Retrofitting makes it possible to measure energy consumption specific to the building.
