water to heat greenhouses with solar energy

On the heights of Marseille (Bouches-du-Rhône), an urban farm produces microgreens for the city’s restaurants. Broccoli, radishes, cabbage or even mustard, it is absolutely necessary to protect the plants from the cold. “This is the very beginning of a plant’s life cycle, the moment when it absolutely must be protected. (…) It only takes one night under frost for the plant to give up the ghost“, explains Benjamin Denjean, co-founder of Paysan Urbain.

Store solar energy

In a bioclimatic greenhouse, there is no heating. The temperature remains positive thanks to water cans that store the sun’s energy during the day. It is an association that helps with the design and financing of these structures. Here, it cost 14,000 euros, but since then, the farmer has had no energy bills. The solution appeals to schools, large and small operators. Since 2015, a dozen bioclimatic greenhouses have been installed in Provence, and as many projects have already been launched.