Junior Research Group Cleanvelope
Climate and energy active building envelopes as component of climate oriented urban development

Cities are key contributors to climate change due to the high energy consumption of buildings, commerce, industry and transport, whilst at the same time particularly suffering from the effects of climate change. As an example, dense, built-up areas lead to urban heat islands and intensify heat-related stress in times of global warming. Building envelopes are an essential field of action for decarbonizing the building stock by improving thermal insulation and by energetically activating them in terms of integrating solar energy technologies, in particular photovoltaics. At the same time, building envelopes provide possibilities for climate-regulating roof and façade greening or socially beneficial roof gardens or recreation areas.

The research group investigates synergetic solutions to resolve the resulting competition for building envelope surfaces and to balance climate protection and climate change adaptation strategies. When suggesting renovation scenarios and designing multifunctional façade systems, the research focuses on a high architectural quality and cultural integrity of the built urban environment. In parallel, dynamic outdoor comfort modelling aims to quantify the impacts of a large-scale energy activation of building envelopes on the urban microclimate and to identify potential for active improvements by extracting and using waste heat from photovoltaic surfaces.

Another research focus is in linking local solar energy solutions to sustainable urban district energy concepts and identifying marketable interactions with the regional and national energy system. An increasing share of fluctuating solar electricity is a great challenge for the power grid. The research group aims to meet the integration challenges at the district level. District-scale modelling of the energy flows incorporating aggregated generation and load profiles allows for development of optimization and energy management strategies, to show the potential for the local and smart use of the locally generated solar electricity. The strategies include electricity exchange across buildings and electricity use across sectors, integrating the heat and transport sector. Electric heat pumps and electric vehicles serve as electricity storages in a smart (micro) grid, but must not overload the local grid due to coincident loading. Combining different load management options has so far only been carried out for single buildings and is now to be aggregated and optimized at a district level.

Last but not least, governance options and implementation strategies in urban planning and development are on the agenda. On the basis of existing stakeholders, processes and tools in Bavarian municipalities, recommendations for practice, approaches and tools are to be developed in order to stimulate the realization of the urban solar potential in an urban climate oriented, social and grid-compatible as well as financially affordable way. In addition, opportunities for participation should be shown in order to include citizens in the decision-making processes, investments and profits of the municipal energy transition.

The research results show typology-oriented roof and system solutions for common types of urban developments, application potentials and ways for the energy activation and greening of the building envelope. The energy and outdoor comfort modeling creates an understanding of system parameters for the integration into urban energy systems. Holistic energy-economical and environmental assessments help to quantify the true value of solar power for the urban district. In addition, recommendations for microgrid business cases, political incentives and the reduction of legal obstacles can be derived. The research group plans to accompany renovation projects in several Bavarian municipalities as real world case studies in order to test the technical solutions, implementation strategies and tools, identify suitable approaches for long-term urban development processes and set impulses also for municipalities outside of Bavaria as well as the national energy system.