Run the buses with the gas produced by local organic waste, to make it a virtuous and educational circle: the idea was of Pierre Mauroy, former Prime Minister and president of the Lille metropolis. This is done with the northern bus transport network, which has become over the years one of the greenest in Europe. Operated by Ilevia, a Keolis subsidiary, the fleet includes 430 buses powered by natural gas vehicle (CNG) and transports 200 million passengers per year. This gas comes for a large part from the organic recovery center (CVO) of the agglomeration, in Sequedin, which produces both compost and biogas from the green waste of the population. “It took ten years to change everything, we wiped away all the plaster”, recalls Erwan Lemarchand, Director of Transitions, Energy, Climate at MEL. The project started with 100 CNG buses, a fleet that has been transported over the years to all 428 vehicles. Lille has become the only French agglomeration where all the buses run on CNG. Now, the time has come to renew the fleet at the rate of around thirty buses per year. The MEL supplements it during peaks of traffic or specific needs of a fleet – a hundred vehicles – subcontracted to Keolis, with an objective of 50% of green vehicles.
Autonomy to be increased
But the copy is not finished. If the gas system is now proven, including in its economic model, with a cost equivalent to diesel, it is to increase energy autonomy. “We cover 30% of our kilometers with what we produce”, specifies Erwan Lemarchand. However, the metropolis (like the region) have made anaerobic digestion a priority, and are pushing for new projects. Thus the MEL even participates in the capital of project companies of 4 farmers, to provide the necessary engineering. Above all, it intends to anaerobic digestion of the sludge from wastewater treatment plants, with great potential for long-term production. That of Marquette, Ovilleo, which manages half of the city’s water, is already operational. Next will come five other stations including those of Houplin-Ancoisne and Wattrelos. In total, the recovery of the sludge from these stations will make it possible to produce more than 15 million Nm3 of biomethane per year, of which 60% will be injected into the gas network. “We will have more than our consumption in ten years”, Erwan Lemarchand hopes.
Besides the buses, the city also wants to transform its dumpsters with household waste. Already 15% of the fleet, managed by the company Esterra, runs on CNG. The collection contract will soon be renewed with the ambition of increasing to 40% of the fleet in CNG. And the agglomeration plans to create two to four NGV refueling stations this time open to carriers.
But the people of Lille want to go beyond. Because if CNG is much cleaner than diesel, it still emits particles and NOx. In early 2021, the MEL will acquire five electric buses, dedicated to small routes serving the hypercenters, in zero emission mode. Then on the horizon two or three years, another reflection is engaged to take – cautiously – the direction of hydrogen. With a significant local advantage, the presence of the Chemicals factory in Loos, whose activity generates fatal hydrogen that is not valued. The idea is to compress this gas and use a hydrogen station to supply buses. The factory produces enough to run around forty. It remains to validate the economic model, the hydrogen buses being particularly expensive to buy. “We don’t know if it’s viable”, indicates the director of the transition, who emphasizes a pragmatic approach, without giving in to the effects of fashion or general excitement.
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