Green energy: abundant scientific research

If the ecological transition cannot be achieved without a change in our practices, technological innovations will also play a key role. When it comes to green energy, a lot of research could bear fruit. Here are three examples.

osmotic energy

Electricity could be produced in all estuaries. In 2013, at the Lumière Matière Institute in Villeurbanne (Rhône), physicist and professor at the Ecole Normale Supérieure (ENS) Lydéric Bocquet and his colleagues rediscovered an energy that had been known since the 1950s but had been somewhat forgotten: osmotic energy.

Specifically, when water with different levels of salinity comes into contact, the salt naturally circulates to balance itself. In fact, it is made up of positively charged sodium and negatively charged chlorine. By installing a membrane that only allows sodium ions to pass through, you create a natural electric battery. The problem then lies in the cost and efficiency of the membranes. In 2015, Bocquet founded the start-up Sweetch Energy with entrepreneurs passionate about applied science. In less than ten years, he succeeded in creating a membrane that is both biologically derived and economically accessible. A first pilot project for the large-scale production of osmotic energy has been launched in the Rhône Delta.

MOF (Hybrid Crystallized Porous Solids)

MOFs also come to the rescue of the environment. What are we talking about? metal organic structuresor hybrid porous solids crystallized in French. They contain tiny cavities, of the order of a nanometer, that is, the size of essential molecules (O₂,H₂,O,CO₂etc.). Hence the selective absorption properties that interest researchers.

Chemist Christian Serre, research director at the CNRS, director of the Paris Institute of Porous Materials (ENS, ESPCI, PSL University), recently elected member of the Academy of Sciences, has devoted much of his career to these materials, which are compared to “molecular sponges”It has created hundreds of variations and has multiplied its applications in the field of green energy (hydrogen production, heat transfer, membranes for batteries or fuel cells) and the environment (capture or valorization of CO₂air pollution control, etc.). His fundamental research work is of interest to the industrialists he works with. In 2021, he also co-founded the startup SquairTech, specializing in indoor air quality.

Hydrogen

Hydrogen is an essential lever for the energy transition: it could partially replace hydrocarbons and its use does not pollute. But today it is mainly produced from natural gas, a process that releases CO₂A sustainable option to this method is water electrolysis, the decomposition of water molecules (H₂O) into oxygen molecules (O₂) and hydrogen (H₂). This requires catalysts such as platinum, a rare metal too expensive for large-scale use.

But, explains chemist Vincent Artero, formerly of the Ulm street and research director at the Grenoble Interdisciplinary Research Institute, “Producing hydrogen, without platinum, with solar energy, is possible. We just need to look to nature for inspiration, especially microalgae.” Vincent Artero and his team have been imitating the active sites of enzymes capable of producing hydrogen, such as hydrogenases, for years. Ultimately, the idea is to produce a “solar fuel” cheap, explains Artero, who already works with manufacturers such as Engie.