Green:Energy

Implementation of energy management software to display digitally recorded values. Development of an automatic reporting system.

As part of the EnOpt 2023/24 package of measures, the aim is to create an asset register, optimize lighting control and ensure energy-efficient operation and maintenance by optimizing building automation.

The COME program is a funding program of the Hessian state government as part of the CO2-neutral state administration project. This program primarily focuses on structural energy efficiency measures (roof insulation, window refurbishment, insulation).

According to the European EU Energy Label Regulation, some light sources are no longer permitted after transitional periods. These are to be successivelyreplaced with efficient LED lights. In addition, new control systems (presence control,  daylight optimization, etc.) are to be tested and used during the refurbishment. If all refurbishment options are implemented, potential savings of up to 80% can be realized.

When refurbishing existing systems, there is considerable potential for savings in many areas. On the one hand, there is a considerable gain in efficiency in the area of motor and fan technology, which primarily leads to electricity savings. On the other hand, highly efficient heat recovery units (HRU) ensure considerable heat energy savings. If the systems are also controlled according to presence and demand, the efficiency potential increases even further.

This type of refurbishment primarily involves refurbishing the fittings, pumps and safety devices in individual buildings. A 1:1 refurbishment only results in potential electricity savings through the new efficient speed-controlled heating circulation pumps. In addition, the temperature level of the heating system at the University of Kassel is being reduced through demand-oriented planning, and the hydraulics and control options of the systems are being optimized, including across systems. With these measures, the heat consumption of buildings can be reduced by up to 25 %.

In buildings with a proven significant hot water requirement (halls of residence, laboratories, etc.), this is generated centrally and distributed throughout the building. As long as there is a simultaneous heating requirement in the buildings, heating the hot water heaters with heating water is the most economical form of generation. As soon as there is no demand for heat in summer, except for hot water, the efficiency of this system decreases considerably because the very large heat distribution networks can only be operated with very high losses. For this reason, air-source heat pumps or solar thermal systems are installed for the summer hot water demand, with central generation. This means that the entire heat supply to the properties can be switched off from mid-May to October.

The local heating pipeline at the South Campus is currently being operated at a higher temperature and pressure than we need to heat the buildings. For example, STW Kassel supplies the district heating at an outside temperature of -12°C with a temperature of 120°C and a pressure of more than 16 bar. In the buildings, however, the heat is required at this AT < 90°C and with a pressure < 10 bar. In addition to high network losses due to the temperatures, the high pressure leads to considerably greater wear in the system. After the system separation, the renovation of the heat transfer points becomes cheaper because the fittings and components no longer have to be designed for such high pressures (PN 16 instead of PN 25). Another advantage is that we will be able to hydraulically integrate renewable energy sources (including the CHP) much better in the resulting local heating network.

An almost infinite number of refrigerators, fridge-freezers and freezers are in operation in the laboratories of the departments, but also in the kitchenettes. At least 140 of these appliances are in operation in FB 10 in the AVZ alone. Many of these appliances are more than 15 years old, so there is considerable potential for energy savings through the further development of technology. Together with the Green Office, a refrigerator refurbishment program is therefore to be launched to create an incentive for the departments to invest in new, modern appliances. As the replacement of such appliances is eligible for funding under the municipal guidelines of the national climate protection initiative, the program for the departments will consist of two parts. On the one hand, the Green Office will provide the service of submitting applications to the project sponsor and handling the funding program. Secondly, the specialist areas will be granted a lump sum as an incentive to take action. The incentive amount depends on the potential energy savings and is set at such a level that after around two years, the electricity cost savings from the new appliances will refinance the funding amount.

Improving the thermal insulation of roofs and walls and renovating and sealing windows are the measures that most fundamentally improve the energy consumption of buildings. Implementing these measures reduces energy requirements. Unfortunately, this type of measure is often very expensive and the refinancing is very long-term, so that technical measures are often preferred to structural measures.