Holistic Approach for Sustainable Heat Energy Services in High-Altitude Rural Communities

This thesis focuses on developing a holistic approach to improve heat energy services in high-altitude rural communities in Kyrgyzstan. Due to remote locations, low-income situations, and limited access to modern heat energy supply, these communities rely on non-sustainable heating methods, leading to pollution, health problems, and local deforestation. Urgent attention is required to address the challenges of heat energy services in high-altitude rural communities. Although, no comprehensive scientific studies are available that focus on the existing issues and provide solutions. In response, this thesis presents a novel and holistic approach to improving heat energy services that incorporate three key elements: current energy demand, future heat demand scenarios, and sustainable heat supply solutions supported by quantitative on-site household surveys.

To identify the current heat demand of a typical community, a validated archetype-based bottom-up model was developed. The results indicated that the age of the buildings, the absence of thermal insulation and the extreme cold climate result in high heat demand and low thermal comfort in Kyrgyz houses. Hence, heat demand for high-altitude rural Kyrgyz houses is up to 5 times higher (250-400 kWh/m2) compared to European houses (90-120 kWh/m2). The findings also highlight the necessity of formulating a strategy to decrease the high heat demand in the future to reduce solid fuel consumption and improve thermal comfort by considering building energy efficiency measures. Regarding future heat demand scenarios based on building energy efficiency, it was identified that due to low-income conditions and limited access to modern insulation materials, implementing building energy efficiency is crucial. To overcome this, the presented research proposed and developed a novel sustainable strategy using affordable and locally available thermal insulation structures such as sheep wool, straw, and reed. As a result, a novel sequential roadmap was developed to gradually reduce heat demand, with the potential to decrease the current heat demand by up to 70 %

Based on the technical potential analysis, it was found that Kyrgyzstan holds favourable conditions for sustainable heat supply through solar energy (with a potential 60 % higher than Central Europe) and biomass energy (abundant due to forest cover). The decision-making framework was established as the research outcome to assess heat supply solutions at the community level using an evaluation matrix considering technical, economic, environmental, social, and geographical factors with the input of experts. The thesis presents five exemplary heat supply solutions assessed in the setting of high altitude. rural Kyrgyz communities and developed the evaluation score. Based on the novel evaluation matrix, a centralised solar district heating system appeared as the suitable system among the other supply solutions.

This thesis recommended building energy efficiency as the key driver to establish the sustainable energy transition in high-altitude rural (Kyrgyz) communities. This research could have broader implications for other rural communities facing similar energy challenges, both within Kyrgyzstan and in other parts of the world. Therefore, the research findings hold significant value for local stakeholders and decision-makers, researchers, providing valuable insights about energy planning for high-altitude rural communities.