28 May 2025 - Energy Efficiency Intelligent Energy Management at Heidelberg University: Wi-Fi with Brains
Dimitri Eckert and Tyler Koller, two trainees at the URZ, have successfully completed their qualifications as IHK Energy Scouts. As part of this qualification, they investigated the potential for considerable energy savings through more efficient use of access points.
Qualified in Climate Protection: Energy Scouts Identify Potential Energy Conservation Measure
Climate change and environmental protection continues to be increasingly urgent and relevant. That is why projects, like the training of Energy Scouts, are of particular importance. Through the promotion of sustainability and energy efficiency, this qualification makes an important contribution to meeting climate targets and reducing the university's ecological footprint. For the past eight years, second-year trainees have received training as Energy Scouts to equip them with the skills to identify potential energy savings in ongoing operations and thereby further strengthen Heidelberg University's sustainability.
Dimitri Eckert and Tyler Koller joined the University Computing Centre in 2023 to become trained IT specialists for system integration. As part of their qualification as Energy Scouts, they attended two workshops in November 2024 and showcased their project with a poster and presentation at the IHK's closing event in March of this year.
For the project, the two put the energy consumption of Heidelberg University's Wi-Fi network under the microscope, specifically its access points (APs). There are 1,544 (and rising) APs installed throughout the university to ensure seamless wireless internet coverage in buildings and on campus. When in normal operation, an AP consumes around 30 watts per hour. This results in a total energy consumption of around 0.5 million kWh per year, which corresponds to approximately one percent of Heidelberg University's total electricity consumption - which amounted to 42.2 million kWh in 2024.
Saving energy through intelligent operation
However, many of these APs remain active even when they are not in use – at night, on weekends, and in unused lecture halls. Using an intelligent control system based on room booking plans, in the future the APs in the 52 lecture halls and seminar rooms will be operated in an energy-efficient standby mode when no events are taking place. This not only cuts the power consumption of the APs in half during operation but also contributes to protecting the environment. In standby mode, it is still possible to connect to the AP, but its range and performance are limited. However, as soon as a connection to the AP is established, it will switch back to normal operation.
According to Eckert, this was the only shortcoming they were able to identify: “The use of Wi-Fi tends to be extremely individual, especially at the university. It is therefore important that the network remains available at all times. The reduced range could pose problems in some cases - this still needs to be reviewed and will hopefully no longer be a problem once the Wi-Fi expansion is complete."
The intelligent control system will only be implemented once the final phase of the current Wi-Fi expansion has been completed. According to the current phase of planning, this is expected to be around the end of this year.
A Small Change with a Big Impact
With a one-off technical expenditure of around 1,500 EUR and a monthly maintenance cost of 100 EUR, the implementation of the project is remarkably cost-efficient. For the 187 APs in lecture halls alone, this would result in annual energy savings of around 6,000 EUR – an investment that would pay for itself in less than four months. However, the potential goes even further: if the remaining 1,357 APs were also intelligently operated, it would be possible to achieve additional savings of over 30,000 EUR per year. The project impressively demonstrates how digitization and sustainability can go hand in hand.
