a solar oven for cooking without electricity

A French woman has developed a system for collecting solar thermal energy, which allows food to be cooked at a lower cost, and without emitting greenhouse gases. More than 150 are already in service, particularly in East Africa.

It is one of the most energy-intensive appliances in a home. An electric oven consumes on average 100 kW/h each year. Suffice to say that in a context of reducing energy consumption and the fight against greenhouse gases, the solar oven developed in Tampere, Finland, by Eva Wissenz and her small company, Lytefire, takes on its full meaning. .

The device takes the form of a 7 m2 vertical wall made up of rows of curved mirrors installed facing the sun.“It is a field of mirrors oriented in such a way that they concentrate sunlight on a focal point, explains the Frenchwoman, on a bread oven in this case, to create heat without any electricity.”

The device also allows you to roast seeds such as peanuts. Here the temperature can reach 300 degrees. Production can reach around a hundred kilos of bread per day, after a heating time of around three-quarters of an hour.

Raised in Corsica, in Saint-Florent, Eva Wissenz has lived in Finland for more than 10 years, attracted by the support and loans offered to start-up businesses or pilot projects by the Scandinavian country. Designed for developing countries, this solar oven allows residents to use the sun’s energy most of the year.

“In countries in which we are very present, such as in East Africa, the sun is there 10 months a year, she explains. This means that for 10 months, there is no deforestation or purchase of polluting fuel. And there is a saving made which allows us to return to wood or coal, but only for two months.”

For Africa, the ovens are made in Kenya, and two trainers offer to help the locals.

Solar bakery training

“We have also created training in solar baking, welcomes the Frenchwoman, which allows us when we arrive somewhere to train young people who do not have a job in this activity, so that they can then create a small local solar bakery which pollutes less, and which creates a little economic stability locally.”

Purchased mainly by NGOs, the Tampere company’s main customers, these autonomous solar ovens also equip refugee camps. Basic, easy to maintain, with a lifespan of 16 to 19 years, 150 copies of the LyteFire solar oven are in operation around the world.

“It’s a machine that’s outside all the time, argues Eva Wissenz. Unlike a photovoltaic panel which will produce electricity, when it breaks, you have to bring another one back from China. Our model is to try to find people locally who will buy a license and manufacture this tool locally.”

The device can also produce steam. The Frenchwoman’s invention even won over the company’s former technical director, now a baker in Normandy, who bakes his bread using a solar oven. Artisans also make it in France.

The company now employs six permanent staff and works between Finland, Switzerland and Kenya. She is also a partner of the laboratory “low tech” from Grenoble, which supports people wishing to install and use a solar oven. Allow 9,000 euros for a turnkey device. A sign that investors, too, believe in the future of the solar oven, the Frenchwoman has just completed, in Finland, a first round of funding, with a fundraising of two million euros.

Go further

His company in Tampere, Finland, Lytefire

Find this column on the app, the website and the international mobility magazine “Français à l’enseignement.fr”