Rooftops could become an increasingly important part of efforts to combat urban heat as rising temperatures drive up cooling demand, with solar panels, green roofs and reflective surfaces offering complementary ways to reduce heat gain and generate electricity.
Selcuk Yerci, chairman of the board of the Middle East Technical University Center for Solar Energy Research and Applications (ODTU-GUNAM), told Anadolu that solar panels could indirectly help mitigate the urban heat island effect by shading buildings and reducing heat gain.
Yerci said the impact of solar panels on urban temperatures should be assessed together with the characteristics of the roof and the shading they provide, rather than based solely on the temperature of the panels themselves.
He noted that solar panels can reach temperatures 20-30 degrees Celsius above ambient air temperature when exposed to sunlight, potentially transferring some of that heat to their surroundings.
However, panels can have a different effect when installed over dark-colored roofs by shading the roof surface, he said, adding that maintaining sufficient ventilation between the roof and panels is critical for system performance.
- Rising heat puts focus on rooftop solutions
Climate change is expected to increase cooling demand as heat waves intensify, Yerci said.
"In a hot climate such as Antalya, the cooling load of a typical office building could increase by approximately 45% by 2050 and 88% by 2080," he said.
The overlap between peak cooling demand and periods of strong solar radiation makes solar power particularly useful in meeting this additional demand, Yerci said.
"The goal should not be to cover every roof with solar panels," he said, noting that photovoltaic systems could be installed in suitable areas, while highly reflective cool roofs and green roofs could be used elsewhere.
Combining green roofs with solar panels could support the performance of both systems, he said, adding that public, commercial and industrial buildings with large rooftop areas could be prioritized.
Solar energy could also be integrated into facade shading systems and expanded to the neighborhood level.
"It may be possible to transform an entire neighborhood into a system that generates and shares energy," Yerci said.
- Building safety key to expanding rooftop solar
Yerci underlined that rooftop solar expansion should also take into account the structural safety of existing buildings, particularly given Türkiye's earthquake risk.
Installing photovoltaic systems on old, damaged or structurally inadequate buildings simply because their roofs are suitable for solar generation would not be appropriate, he said.
For new urban developments, solar energy should be incorporated into the design from the outset, with building orientation, height and spacing affecting energy performance.
"Cool and green roofs, afforestation, shading and solar energy systems should not be considered alternatives to one another, but as components of the same climate strategy," Yerci said.
By Humeyra Ayaz
Anadolu Agency
energy@aa.com.tr
