Saturday, April 18, 2009

Cardboard Boxes Turn into $5 Solar Ovens

When Jon Bohmer sat down with his two little girls for a simple project they could work on together, he didn't realize they'd hit upon a solution to one of the world's biggest problems for just $5: A solar-powered oven.

Inventor Jon Bohmer with the oven he has made out of a cardboard box.

The ingeniously simple design uses two cardboard boxes, one inside the other, and an acrylic cover that lets in the sun's rays and traps them. Black paint on the inner box, and silver foil on the outer one, help concentrate the heat. The trapped rays make the inside hot enough to cook casseroles, bake bread and boil water. What the box also does is eliminate the need in developing countries for rural residents to cut down trees for firewood. About 3 billion people around the world do so, adding to deforestation and, in turn, global warming.


By allowing users to boil water, the simple device could also potentially save the millions of children who die from drinking unclean water. Bohmer's invention on Thursday won the FT Climate Change Challenge, which sought to find and publicize the most innovative and practical solution to climate change. "A lot of scientists are working on ways to send people to Mars. I was looking for something a little more grassroots, a little simpler," Bohmer said Thursday. Bohmer, a Norwegian-born entrepreneur based in Kenya, said he also had been looking at solutions "way too complex, for way too long."

"This took me about a weekend, and it worked on the first try," Bohmer said. "It's mind-boggling how simple it is." The contest was organized by the Forum for the Future -- a sustainable development charity -- and the Financial Times newspaper. Among the judges were British business magnate Richard Branson and environmentalist Rajendra Pachauri. The public also voted on the finalists. Bohmer's invention beat about 300 other entries, including a machine that turns wood and other organic material into charcoal, wheel covers that make trucks more fuel efficient by reducing drag, and a feed supplement for livestock that reduces the methane they emit by 15 percent.


Bohmer named his invention the Kyoto Box, after the international environmental treaty to reduce global warming. The box can be produced in existing cardboard factories. It has gone into production in a factory in Nairobi, Kenya, that can churn out about 2.5 million boxes a month. Bohmer has also designed a more durable version, made from recycled plastic, which can be produced just as cheaply. He envisions such cardboard ovens being distributed throughout rural Africa. "In the West, we cook with electricity, so it's easy to ignore this problem," he said. "But half the world's population is still living in a stone age. The only way for them to cook is to make a fire. "I don't want to see another 80-year-old woman carrying 20 kilos of firewood on her back. Maybe we don't have to."

2 comments:

mmmmm said...

Those of us who have worked for years to promote awareness of solar cooking are thrilled at the prize won by Jon Bohmer for his solar cooker. The publicity it has generated will help raise the profile of this simple, powerful and renewable technology.

It is however, not a ‘new invention’.

The cardboard solar box cooker, for which Mr. Bohmer won $75,000 from the FT Climate Change Challenge is a variation on one of the many designs that have been freely available to the public for years on Solar Cookers International’s archive. http://solarcooking.org/


The archive website contains extensive data on the design, construction, dissemination and international use of solar cookers to reduce carbon emissions and deforestation.

After logging on to the SCI web archive, users can click on build a solar cooker. There they will find detailed plans for a variety of cardboard, wood, metal and plastic solar box cookers, solar panel cookers and solar parabolic cookers.

Solar cooker advocates like Mr. Bohmer who have been inspired by the many designs currently available often come up with new variations and post them to our website where they can be shared with the rest of the world.

The solar box cooker is the oldest type of solar cooker. It was first widely promoted by two American women who were among the founders of SCI in 1988. Our organization was initially know as Solar Box Cookers International. Another of SCI’s founders, Robert Metcalf has been traveling the world for decades teaching people how to build and use solar cookers not only for cooking but also for solar water pasteurization.

When refugee populations in Africa began expanding in the early 1990s and access to cooking fuel and clean water became a serious problem for these people, a more portable version of the cardboard box solar cooker was developed by Roger Bernard. Tens of thousands of these have been made and sold or given away.

The largest solar cooker project currently underway is in three Darfur refugee camps in Chad. The women in those camps have manufactured and distributed more than 30,000 cardboard and aluminum foil Cookits. Trips outside the camp to gather firewood have been reduced by 86%.

Almost all solar cooker projects, including the one in Chad are currently funded by small non-profits. There is little to no government funding available. And yet many governments continue to subsidize the purchase of bottled cooking gas by up to 50% and the charcoal trade is destroying the forests of Africa and south Asia. This must change.

mmmmm said...

Those of us who have worked for years to promote awareness of solar cooking are thrilled at the prize won by Jon Bohmer for his solar cooker. The publicity it has generated will help raise the profile of this simple, powerful and renewable technology.

It is however, not a ‘new invention’.

The cardboard solar box cooker, for which Mr. Bohmer won $75,000 from the FT Climate Change Challenge is a variation on one of the many designs that have been freely available to the public for years on Solar Cookers International’s archive. http://solarcooking.org/


The archive website contains extensive data on the design, construction, dissemination and international use of solar cookers to reduce carbon emissions and deforestation.

After logging on to the SCI web archive, users can click on build a solar cooker. There they will find detailed plans for a variety of cardboard, wood, metal and plastic solar box cookers, solar panel cookers and solar parabolic cookers.

Solar cooker advocates like Mr. Bohmer who have been inspired by the many designs currently available often come up with new variations and post them to our website where they can be shared with the rest of the world.

The solar box cooker is the oldest type of solar cooker. It was first widely promoted by two American women who were among the founders of SCI in 1988. Our organization was initially know as Solar Box Cookers International. Another of SCI’s founders, Robert Metcalf has been traveling the world for decades teaching people how to build and use solar cookers not only for cooking but also for solar water pasteurization.

When refugee populations in Africa began expanding in the early 1990s and access to cooking fuel and clean water became a serious problem for these people, a more portable version of the cardboard box solar cooker was developed by Roger Bernard. Tens of thousands of these have been made and sold or given away.

The largest solar cooker project currently underway is in three Darfur refugee camps in Chad. The women in those camps have manufactured and distributed more than 30,000 cardboard and aluminum foil Cookits. Trips outside the camp to gather firewood have been reduced by 86%.

Almost all solar cooker projects, including the one in Chad are currently funded by small non-profits. There is little to no government funding available. And yet many governments continue to subsidize the purchase of bottled cooking gas by up to 50% and the charcoal trade is destroying the forests of Africa and south Asia. This must change.