Heat-holding rocks dramatically reduce the amount of cooking fuel needed - and solar panels provide electricity as well
Cooks at a community kitchen in Kampala's Nakasero Hill business district are preparing a traditional breakfast of green bananas in offal sauce using a very untraditional means of cooking - volcanic rocks.
It's a method that some are hoping will take off across Africa, to help protect forests and improve the lives of women.
"Rocks for fuel is a reprieve to all women in Africa," said Susan Bamugamire, one of the 55 cooks in the community kitchen set up by city authorities in the Wandegeya Market shopping mall to help feed local workers.
"Save for the high cost of purchasing and installing it, the special cookstove is something every woman will crave to have in her kitchen," she said, saying it would largely free women from having to seek out firewood, charcoal or kerosene.
But cost is an issue in a country where a third of the population live on $1.90 or less a day and even small domestic stoves are priced at $100.
The stoves use heat-holding volcanic rocks broken down to the size of charcoal. The rocks are heated using starter briquettes and then remain hot for hours with the help a fan blowing a continuous flow of air over them.
According to Rose Twine, the director of Eco Group Limited - the Kampala-based company that produces the stoves - the main aim is to provide an efficient form of cooking energy that is user friendly and good for the environment.
"It pains me when I see people cut down trees, some of them indigenous and decades old, just for the sake of making charcoal or firewood," said Twine.
"It is now good that we can talk of an alternative," she told the Thomson Reuters Foundation.
The volcanic rocks can be repeatedly heated for up to two years with the aid of the fan, which is solar-powered and needs very little energy. Any surplus solar power produced can be used to light the house, run a radio and charge mobile phones, Twine said.
Alternatively, the fan can be run off mains electricity if the owner's home or business is connected to the power grid, she said.
It is the cost of the fan, battery and solar panel that push up the stove's production cost, pushing it out of reach of most people in Uganda.
"We can only achieve the environmental benefits of these stoves if they are made affordable for poor Ugandans who desperately need them," said David Illukol, a senior mechanical research engineer at the government-run Uganda Industrial Research Institute.
"All we need is further research on how to reduce the costs of production, and perhaps (on) maintaining them," the engineer said in an interview.
Despite the cost, more than 4,500 individuals and institutions in Uganda - including schools - are now using the stoves, according to Eco Group Limited.
The Kampala city authority has installed 230 of the stoves at Wandegeya Market where Bamugamire and her colleagues rent the premises from the government.
There are plans for the stoves to be used in other parts of the continent too.
Twine's company began exporting them to Rwanda this year, and plans to take them to Kenya and Somalia as well.
An umbrella group of more than 1,000 climate organisations and networks - the Pan African Climate Justice Alliance - wants to spread the cooking method across Africa, according to its secretary general Mithika Mwenda.
Volcanic rocks have the potential to become a key cooking method for East Africa and perhaps the entire continent, engineer Illukol said.
They are a largely environmentally friendly form of cooking because - unlike charcoal, kerosene, gas and firewood - they do not emit climate-changing gases and produce no smoke at all, he said.
About 94 percent of Ugandan households use firewood or charcoal for cooking, according to the Uganda Bureau of Statistics.
Only 20 percent of households had access to electricity in 2014, and most of those connected to the grid rarely use electricity for cooking because of the high costs involved, the statics bureau said.
Demand for wood for fuel has put pressure on Uganda's shrinking forests.
The country had some 3 million hectares of tropical forests under government control at the beginning of the 20th century. But by 1999, tropical forest cover had fallen to about 730,000 hectares or 3.6 percent of Uganda's land area, according to the U.N. Food and Agriculture Organization.
"If we can stop using firewood and charcoal completely, then we will have saved a huge volume of wood that is used for fuel every year, and that is good for our environment," said Illukol.