As climate change concerns are rising rapidly, energy efficiency promotion and implementation could be sustainable solutions within energy transition. In this context, buildings, including educational ones, play an important role in reducing energy needs and promoting energy efficiency since they account for a significant share of the total energy consumption. As a case study for this research, the educational building of Kazakh-German University was selected. Following the national and international building standards, energy performance parameters were estimated. Current heat losses and performance have been estimated as baseline scenario settings. The impact of retrofitting measures on energy efficiency performance of the buildings under the four scenarios was calculated. Under the minor scenario, retrofitting interventions will lead to annual energy savings of 36.9 kWh/m² and a 48% CO₂ emission reduction, whereas under the major scenario, the annual energy savings will increase to 77.76 kWh/m² and a nearly 82% CO₂ emission reduction. The integration of a solar thermal system with capacity 400 kWh, assuming that the heat demand was reduced under the minor retrofitting scenario, can decrease heat energy consumption and CO₂ emissions to 35%. As upfront costs of the energy efficiency measures are high, a carbon offset mechanism could facilitate the implementation of university building modernization.

During the energy transition, new types of electrical equipment, especially power electronic devices, are proposed to increase the flexibility of electricity distribution grids. One type is the solid-state transformer (SST), which offers excellent possibilities to improve the voltage quality in electricity distribution grids and integrate hybrid AC/DC grids. This paper compares SST to conventional copper-based power transformers (CPT) with and without an on-load tap changer (OLTC) and with additional downstream converters. For this purpose, a corresponding electricity distribution grid is set up in the power system analysis tool DIgSILENT PowerFactory 2022. A DC generator like a photovoltaic system, a DC load like an electric vehicle fast charging station, and an AC load are connected. Based on load flow simulations, the four power transformers are compared concerning voltage stability during a generator-based and a load-based scenario. The results of load flow simulations show that SSTs are most valuable when additional generators and loads are to be connected to the infrastructure, which would overload the existing grid equipment. The efficiency of using SSTs also depends on the parameters of the electrical grid, especially the lengths of the low-voltage (LV) lines. In addition, a flowchart-based decision process is proposed to support the decision-making process for the appropriate power transformer from an electrical perspective. Beyond these electrical properties, an evaluation matrix lists other relevant criteria like characteristics of the installation site, noise level, expected lifetime, and economic criteria that must be considered.