Every city has a massive potential to cost-effectively boost renewable energy use at the local level, according to a new IRENA study of more than 3,500 conurbations. However, to achieve this transformation requires designing smart, integrated urban energy systems that can manage variable power produced by solar panels and wind turbines, the report, called Renewable Energy in Cities, concludes.

The analysis finds that established cities which have lower building turnover rates will largely rely on retrofits and technologies that can be added relatively easily to existing buildings, such as heat pumps and rooftop solar.