In Alsace, a town heats up with miscanthus, an ecological plant

Forget oil, gas or electricity: in this town of 1.200 inhabitants about fifteen kilometers from Mulhouse, heating is provided by this rhizomatous grass native to Asia resembling reed.

The first plot was planted in 1993.

"We were really the first in France", recalls Mathieu Ditner, former mayor of Amertzwiller (since merged with Bernwiller) and retired farmer. "Now it's all over the place."

Initially, the town uses miscanthus for its purifying properties: it lowers the level of nitrates in the water. Then, about ten years ago, came the idea of ​​harvesting it and using it as biofuel in the communal boiler, instead of woodchips.

"Unlike the wood where you have to wait 50 years for it to grow back, there is a harvest every year", compares the current mayor, Patrick Baur, while in the field behind him the long golden stems are mown in a cloud of dust.

Twenty-seven hectares are cultivated by a dozen farmers, who sell for 110 euros per ton of miscanthus. The annual harvest will heat public buildings and around 70 homes.

"A good deal"

"Basically, it was intended to heat buildings in the town, such as schools and churches, but some residents were offered to connect and they don't regret it!", smiles the 59-year-old mayor: "At a rate of 0,077 cents per kilowatt, it is much lower than other products, electricity, fuel oil or gas, especially at the moment."

Owner of a house bought ten years ago and connected to this heating system, Damien Monnier admits to having been "a little worried" at the start. But today, he is convinced: "We made a good deal".

For the heating and hot water of his 180m2 accommodation, he pays 1.500 euros per year, subscription included: "it's the best value for money I've ever had", he testifies, saying to himself "Serene about inflation".

But its stable price is not the only interest of miscanthus: "it grows on its own, without fertilizers or phytosanitary products. It is a perennial plant", lists the mayor.

And the outlets are numerous: heating, horticultural mulching, animal litter, biomaterials...

In Bernwiller, the mayor intends to use it as insulation in the renovation of a building. In the school yard, miscanthus shavings around the play area cushion children's falls.

Depolluting

Sonia Henry, Soil and Environment Laboratory lecturer at the University of Lorraine/INRAe, has been working for several years on this plant which cleans up the soil of hydrocarbons.

"Miscanthus has the ability to adapt to many environments, including brownfield soils that are contaminated," she explains. "Afterwards, it must not become the miracle plant either and we find this species everywhere, otherwise we will fall back on monoculture, which we are currently trying to reduce".

According to France Miscanthus, an association created in 2009 to structure the sector, around 11.000 hectares are cultivated in metropolitan France, an area that has doubled since 2017.

“A lot of people come to see what we have done”, assures the mayor of Bernwiller, who willingly complies with the exercise.

On harvest day, about twenty students from Metz who work on the sustainability and diversification of agricultural enterprises are visiting.

"It's a plant that has a future on industrial themes, bioplastics" underlines their supervisor, Guillaume Dubaux, teacher in agronomy.

Hervé Lapie, secretary general of the FNSEA notes that "it is developing, it is part of alternatives such as hemp, plants which consume less fertilizer, phytosanitary products and which present interesting outlets". Farmer in the Marne, he himself will plant some for the first time this year, a "big investment" at the start.

Having had to pay 12.000 euros for around 3,5 hectares, he will have to wait two to three years before the first harvest that he intends for mulching or biofuel.