Civil Engineering Departmental Seminar - From net-zero carbon neighborhoods to net-zero carbon cities: synergistic integration of solar energy systems and nature-based solutions for climate positive cities

From net-zero carbon neighborhoods to net-zero carbon cities: synergistic integration of solar energy systems and nature-based solutions for climate positive cities

Addressing climate change is a major challenge due to shifted weather patterns and extreme events that threaten well-being. Moreover, half of the global population lives in cities and is responsible for almost 70% of global carbon emissions. Therefore, the elimination of these emissions and mitigation of their environmental impact through innovative urban transformation solutions at neighborhood and city scales is critical. In this context, solar energy technologies and building-tailored integration of photovoltaics (BIPV) offer a promising pathway toward achieving climate-neutral urban environments. In this work, we investigated the net-zero urban energy transition with the elimination of both operational stationary and transportation carbon emissions of private cars by combining PV building integration design with Nature-based solutions (NBS) such as tree planting and green roofs at the neighborhood and city scales. A residential building block of six-story buildings in the city area of Ioannina, Greece, was selected to apply the BIPV-greenery energy and carbon balances. The results show that neighborhood buildings can be transformed to zero-emission before 2030 with only rooftop PV, green infrastructure, and grid decarbonization at the same rate as the previous years. Including PV façade integration combined with greenery on roofs or walls, both EV charging and offsetting the emissions of remaining conventional private cars are achieved. Upscaling to the city, decarbonization of all operational emissions can be feasible until 2030 with available roofs covered by photovoltaics, current urban forests, and dense planting of trees for nearly 70% of carbon emissions and the remaining 30% covered by a combination of reducing mobility emissions, adding green roofs at flat rooftop PV installations, green walls or façade PV installations. Since all the combined components are currently available, focus should be placed on improving their adaptation through co-creation and regulation support.