Projects
The nationwide energy supply is to become climate-neutral and simultaneously make us less dependent on imported fossil fuels. The expansion of renewable energies is therefore a central pillar of the energy transition. THM also wants to contribute to this. For several years now, all of its properties have been supplied exclusively with green electricity. Nevertheless, as much as possible of electricity and heating consumption is to be covered by its own renewable energy sources. As shown below, numerous projects have already been and are being implemented to this end.
This project is funded by the European Regional Development Fund as part of the Union's response to the COVID-19 pandemic.
The idea of utilizing wastewater heat had been around at THMfor some time, but concrete implementation began in 2022. FM/ECO2 developed an energy concept and visited a wastewater heat recovery plant in Regensburg. With the funding commitment from the European Regional Development Fund (ERDF) – EU-REACT, the concrete planning and implementation of the plant began.
Due to the relatively high year-round temperatures of 8-20 °C, wastewater is an ideal heat source for the sustainable and efficient operation of heat pumps. In this case, the wastewater flows from the public sewer into a shaft screening plant. From there, the liquid medium is pumped into a heat exchanger in the building, while the solids are returned directly to the sewer. A heat pump, or a chiller in summer, is operated via a heat exchanger. The available heat output is approximately 600 kW (heat source output). This allows the heat pump to provide around 850 kW of heat output for the C-Campus, which roughly corresponds to the required heat output for the university campus in Friedberg.
In summer, the chiller uses the wastewater for cooling. This also allows for the generation of at least 600 kW of cooling.
Due to the current increase in energy prices, the project is expected to pay for itself within a few years.
The "Wastewater Heat Recovery" project at THM focuses on the technical use of wastewater heat to increase energy and resource efficiency. It also serves as a real-world laboratory, a research and study facility, and is funded by the European Regional Development Fund as part of the EU's response to the COVID-19 pandemic. www.efre.hessen.de
Publications
- 19.12.2023: THM utilizes "previously untapped treasure", bi-medien
- 30.08.2023: Technische Hochschule Mittelhessen now heats with wastewater, Hessenschau
- August 25, 2023: Contribution to the energy transition - Visit by Klara Geywitz, Federal Minister for Housing, Urban Development and Construction
- May 23, 2023: Into the heating system instead of the sewer - Giessen's mayor Frank Tilo Becher and Ayse Asar, State Secretary in the Hessian Ministry of Science and Art (HMWK), put the system into operation.
Photovoltaic systems
The university plans to gradually equip all suitable roof surfaces of the THM with photovoltaic systems. The electricity demand of the properties is so high that currently 95% of the self-generated electricity can be used within the buildings themselves.
If a building is suitable based on its electricity consumption and its unobstructed, unshaded roof area, more detailed planning is carried out. The aim is to fit as many modules as possible on the roofs to achieve the highest possible electricity yield. In the future, biodiversity and extensive green roofs in conjunction with PV will also play a role. The goal is to combine green roofs and photovoltaic systems. With the completion of the system on buildings C15/C16, the university will have approximately 350 kWp ofcapacity .
Projects already completed:
- Building D10 Giessen, 43 kWpeak, built in 2020/2021
- Building D11 Giessen, 38 kWpeak, built in 2020/2021
- Building C11 Giessen, 29 kWpeak, built in 2020
- Building C15/C16 Giessen, approx. 78 kWpeak, built in 2022/2023
- Building A20 Giessen, 23 kWpeak, built in 2018/2019
- Building B1 Friedberg, 65 kWpeak, built in 2020
- Building A5 Friedberg, 73 kWpeak, built in 2018/2019
The installation of additional systems consequently increased the amount of solar power generated. In 2021, it was more than eight times higher than four years earlier, as the following graph shows.
Further photovoltaic systems are planned for installation in the coming years. Following consultation with the historic preservation authorities, buildings B10 and B11 are slated for the next phase. Expansion on the D-Campus and on the roof of building A12 will also be prioritized in the coming years. As part of the facade renovation of building C10, photovoltaic modules will be integrated into the facade on the southwest side, as well as on the roof and in the area of the emergency stairwell.
Solar thermal energy cafeteria
Since the Department of Mechanical Engineering no longer needs the existing solar thermal collectors on building A15 for its research purposes, they will be repurposed on campus to further increase the share of renewable energy. Specifically, the collectors will contribute to the hot water supply for the cafeteria. The cafeteria has a year-round heating demand, which is currently met entirely by a district heating connection.
This project requires minor modifications and will be implemented soon.
