It is “a huge logistical challenge” that opens. From January 2024, local authorities will have the obligation to offer companies and individuals solutions for recycling their food waste, most of which have been buried or incinerated until then. In Nantes, while several initiatives are being launched (and in particular that of the municipality, in the northern districts), a study unveiled this Wednesday shows that we will have to move up a gear if we want to recover and enhance the whole of this deposit.
“Between households, which represent 57% of waste producers (with 45 kg per year and per inhabitant), restaurants, schools in metropolitan France, etc. this represents at least more than 50,000 tonnes per year, says Guilhem Andrieu, climate energy project manager at the Nantes region urban planning agency (Auran). Local compost will therefore not be enough to absorb everything. Anaerobic digestion is a complementary way. We could run one out of two buses on green gas if all bio-waste were recycled in this way! »
About twenty biogas projects in the region
Unlike composting, which generates a material for the enrichment of the soil, methanization is a process of degradation of organic waste which makes it possible to produce biogas, then biomethane. In Loire-Atlantique, only one site is currently capable of this, the Machecoul methaniser, which receives more than 500 tonnes of rotten fruit, peelings or flowers from the Nantes MIN, which has embarked on a 100% recycling. The gas thus produced is injected into the networks, but only represents the equivalent of the consumption of 25 households. “Bio-waste also produces CO2, which is then transported and used in greenhouses”, explains Veolia, responsible for transport.
In the Pays-de-la-Loire, 270,000 tons of food waste are currently treated in eleven methanation sites. But GRDF hopes to go much further, with the objective that green gas represents more than 27% of total consumption in 2030 (compared to 2% currently). A project with the canteens of Nantes Métropole could soon send half of the leftover meals collected to composting, the other to methanization. To do this, 23 new methanizers should be built in the region by 2025, such as those in Trans-sur-Erdre or Nort-sur-Erdre, In Loire-Atlantique. Véronique Bel, GRDF customer center west director, is optimistic. “We are aiming for 100% green gas by 2050”.