An eight-meter-diameter parabola-mirror associated with a motor transforming heat into mechanical energy: a new mini solar electric generator of 1 kW has been submitted since the end of June to the critical eye of researchers from the CNRS laboratory in Odeillo.
In ten or fifteen years perhaps we will see the neighborhood "plates" flourish. "Enough to reduce the combustion of fossil fuels by 10 to 15 percent, reduce CO2 emissions, slow down the warming of the atmosphere and its foretold catastrophes", explain the researchers.
The theoretical principles have been known for a long time. The "concentration" of solar rays on mirrors, to create high temperatures, is the specialty of the CNRS laboratory in Font-Romeu, the solar center for high temperatures, at an altitude of 1500 meters in the Pyrenees.
The Stirling engine, named after its inventor in 1816, is based on the hot compression and cold expansion cycle of a gas, thanks to an external supply of heat. It produces enough energy to drive an alternator.
“The combination of the two, however, is not as simple as it seems. The dishes must be optically efficient, the production and maintenance costs allow commercial operation, ”explains Jean-Michel Gineste, project manager in the PROMES laboratory (Processes-Materials and Solar Energy) at CNRS.
Already tested in Germany (the main funder of the program) and in Spain, the parabola-Stirling finds in Odeillo, at altitude, "extreme" sunshine conditions and amplified heat exchanges (bright sun, cool days or cold winters), allowing to study the device under severe conditions.
"It will take two years of detailed and permanent measurements to improve the already attractive yields," the researchers explain. Modest-sized Stirling dishes are already more efficient than photovoltaic systems, and just a little less than wind turbines.
“Left dormant in the mid-80s, after the effects of the oil shocks had eased, solar electricity is once again in full light: non-polluting by definition, it can significantly reduce greenhouse gas emissions. greenhouse, ”explains the scientist.
“To produce energy, by definition, you need the sun. And the + solar belt + of the earth generally corresponds to arid or semi-arid zones, where the installation of satellite dishes can be declined in many ways, ”explains Jean-Michel Gineste.
Industrial-sized “solar farms” for mass production, or individual decentralized installations, the relatively small dishes are easy to use.
The electricity produced could allow the extraction of hydrogen from water. The sun would thus provide the fuels of the future in sunny and underdeveloped areas for use in the developed North.
A new enthusiasm seized the Odeillo teams, again at the forefront of the news. This fall, a European laboratory will be set up, the researchers explain, bringing together all the scientific solar energies of our continent.