An unknown plant, miscanthus, attracts the curious in a village in Alsace

Forget oil, gas or electricity: Bernwiller, a small town in eastern France, is heated with… miscanthus, a rhizomatous grass native to Asia, whose culture is developing in the country due to of its ecological properties.

The first plot of this reed-like plant was planted in this town in Alsace in 1993: “we were really the first in France”, recalls Mathieu Ditner, the 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.

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

“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! “, explains the current mayor, Patrick Baur: “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”, with the rise in prices linked in particular to the war in Ukraine.

Owner of a house connected to this heating system, Damien Monnier admits to having been “a little worried” at the start. But today, he welcomes this “good deal”.

Miscanthus has other advantages: “unlike wood where you have to wait 50 years for it to grow back, there is a harvest every year”, explains Patrick Baur, while in the field behind him the long golden stems are mowed down in a cloud of dust.

“Perennial Plant”

“It grows on its own, without fertilizers or phytosanitary products. It is a perennial plant,” he points out.

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.

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 mainland France, an area that has doubled since 2017.

“A lot of people come to see what we have done,” assures the mayor of Bernwiller.

On harvest day, about twenty students from Metz (east) who work on the sustainability and diversification of agricultural enterprises pay a visit. “It’s a plant that has a future on industrial themes, bioplastics”, underlines their supervisor, Guillaume Dubaux, teacher in agronomy.

“This is one of the alternatives such as hemp, plants which consume less fertilizer and phytosanitary products and which present interesting outlets”, explains for his part the secretary general of the agricultural union FNSEA, Hervé Lapie.

Farmer in the Marne (north-east), he will plant it himself for the first time this year, a “big investment” at the start (12,000 euros for around 3.5 hectares) with a first harvest expected by two to three years, whether intended for mulch or biofuel.