Greater Lyon, France
The Lyon metropolis, located in the Auvergne-Rhône-Alpes Region, encompasses 58 municipalities, with a population of 1.4 million. As France’s second largest metropolis and capital of the Auvergne-Rhône-Alpes Region, Lyon is not only renowned for its rich historical and architectural heritage, but also ranks among the leading French metropolis in climate action. With a clear vision to achieve climate neutrality through the collective engagement of all its citizens, Lyon has made it a priority to decarbonise energy consumption, particularly in heating and cooling—sectors responsible for a significant portion of the city’s energy usage.
District Heating: the key to decarbonisation
For Lyon, district heating and cooling networks are considered an essential tool to achieving their heat detox, allowing for the decarbonisation of the energy supply. Between 40% and 50% of Lyon’s energy needs come from heating alone, making it a critical target for reducing greenhouse gas emissions. In 2020, already 60% of Lyon’s district heating energy mix came from renewable or recovered sources. That share has since increased to 66%, and it is now aiming for 80% by 2030.
The ambition goes beyond greening the energy mix. Lyon is rapidly expanding its district heating network, which has already grown from serving 80,000 homes in 2020 to 120,000 today. The metropolis plans to connect up to 200,000 homes by 2026, a 2.5-fold increase in just 6 years. For this, all the existing heating networks are being expanded or densified, with the plan of creating 4 to 5 new networks: one for cooling, one for hot and cold, and two or three large-scale new heating networks. This expansion will allow households previously reliant on fossil fuels like gas and oil to switch to a greener, more stable, and affordable energy source.
The social benefits of district heating
The expansion of district heating is not just about reducing emissions; it is also designed to alleviate energy poverty, for more resilient communities. Thanks to support from national schemes such as the ADEME’s heat fund, Lyon’s district heating networks benefit from subsidies, which help lower costs for consumers. This combination of financial support and a greener energy mix enables Lyon to offer stable and affordable energy prices. Energy prices are reduced, sometimes by hundreds of euros compared to alternatives like fuel or gas.
Additionally, district heating offers more stability to households, as a highly reliable system: any incident can be addressed quickly, ensuring minimal disruption. If there is a problem, the heating is restored within minutes or hours, sparing residents the headaches that can come with traditional heating systems.
A cocktail mix of detox ingredients
To support its district heating networks, Lyon is increasingly relying on renewable energy sources. Indeed, they are diversifying its energy mix to include geothermal energy, industrial heat recovery, heat from household waste and wastewater, solar panels, and heat pumps. This multi-source approach ensures resilience while reducing the need for more traditional fuels like biomass, which, although renewable, is not the first choice for Lyon. While burning wood for heat is necessary, Lyon wants to explore more innovative, efficient, and resource-conscious systems.
For example, Lyon has already signed an agreement to recover 30 GWh of heat from an industrial site in Vénissieux. Additionally, they are using wastewater heat recovery, where wastewater at temperatures between 15°C and 25°C is used to heat entire neighbourhoods. One particularly innovative project involves circulating water beneath a neighborhood undergoing urban revitalisation. This water loop, combined with heat pumps, will produce both heating and cooling, while photovoltaic panels installed on rooftops will generate electricity to power the system. These efforts contribute to Lyon’s goal of creating an integrated, resilient, renewable system with zero combustion and zero harmful pollutants.
Main challenges to detoxify heat:
- Integrating heating plants into the urban landscape: Unlike hidden fossil fuel systems, district heating requires visible infrastructure, such as heating plants and solar panels. Public acceptance is key, and Lyon aims to make these systems architecturally appealing, potentially turning them into symbols of sustainable living.
- Strategically expanding district heating: Lyon is mapping out priority areas for district heating and determining where other renewable solutions like biogas, solar thermal, or geothermal are more suitable.
- Reducing consumption: The 2019 energy plan set targets for a 30% reduction in energy use and 43% in greenhouse gas emissions by 2030. However, updated European goals now require a 55% cut, pushing Lyon to accelerate efforts through new networks and efficiency measures.
Where they are in the heat strategy
Lyon's Heat Detox
Key Heat Figures:
- Energy consumption of heating 40-50%
- Percentage of renewables in heating system: 66%
- Aiming at 75-80% by 2030
Covenant Figures:
- Signatory to the Covenant of Mayors since 2008
Emission reduction ambitions:
%GHG emissions reductions by 2030: 30%
- Green City Accord signatory