The cities of Lyon, Munich and Vienna will deliver smart energy solutions under a €29 million (£22.6m) project.
Around €24 million is funded by the European Commission.
The five-year Smarter Together programme aims to improve citizen’s quality of life, focusing on district heating and renewable projects for low energy districts.
It also includes smart data management platforms, smart services for integrated infrastructures and sustainable mobility solutions such as electric vehicles (EVs).
The three cities expect a major retrofit of buildings to reduce their carbon emissions by 50%.
Around 17.2MW of new green capacity would be installed in the districts and low carbon vehicles would save around 95.5 tonnes of CO2 per year.