The City of Nice

With 344,000 inhabitants, Nice is the 5th biggest city in France. Nice is situated in the French Riviera and is one of the top tourist destinations in Europe, attracting around 5 million visitors per year.

The Metropole Nice Côte d’Azur, an intercommunal structure made up of 49 cities around Nice, has the ambition to become the French laboratory of the energy transition and be one of the frontrunners of sustainable development in France and Europe.



Based on this political commitment for sustainability, the project “Grand Arenas” was conceptualised in 2011. The international business quarter situated near the international airport of Nice Côte d’Azur will increase fivefold to 49 hectare and revolve around two key hubs: a congress centre and a multifunctional meeting space. The whole quarter is based on an urban planning concept of mixed-use that integrates businesses, shops, hotels and diverse residential buildings, including social housing, to ensure a social mix.

A vital part of the sustainability aspect of “Grand Arenas” project is an innovative waste heat recovery process to serve a neighbourhood through a low temperature district heating network with waste heat from the sewage system. In a first phase, operational by the end of 2018, a block of 20,000 m2 of office and hotel space will be powered by the north-south sewage collector.



Wastewater leaving homes and offices, especially hot wastewater, is an energy source that can be used for heating buildings. Sewage heat recovery systems are therefore an ideal low-carbon source for cities to supply a district heating network. The Nice “Grand Arenas” district heating network will include a substation equipped with heat pumps for supplying both heating and cooling to buildings. Since the buildings present mixed-use, a heat pump will guarantee the balance of heating and cooling supply and return from one building to another. Additional cooling storage is required to achieve an optimal balance for heating and cooling in the system. Photovoltaic thermal hybrid solar collectors, producing both thermal and electric power, will also be part of the concept to reach a high renewable and waste heat energy share.

Real-time monitoring data to map all power flux and CO2 emission will be gathered and this information will be made available to the consumers. The control system will be able to provide the following key information:

  • Energy balance of the district showing the share of renewable energy
  • Source of energy used as a function of time and optimal configuration
  • Societal benefits arising from energy solidarity between users


More information on heat recovery from waste water management


Header photo credits: IStock/Ville de Nice