The widespread use of charcoal for cooking in African cities can cause devastating damage to forests up to 300 km away, scientist Sebastian Rodriguez-Sanchez found while working on energy and agriculture issues in West Africa.

So in 2015, he co-founded a business to try to fix the problem by weaning people off charcoal made by smouldering wood and onto bottled gas, a fuel common in his home country of Mexico.

So far, efforts to introduce cleaner stoves that burn less fuel have been led mainly by aid agencies working in rural parts of Africa and Asia and have had limited success. But a new push by businesses targeting urban areas aims to shift the dial.

For families in the Tanzanian city of Dar es Salaam, where Rodriguez-Sanchez started his business, KopaGas, the $150 cost of a gas stove and canister equals half the average monthly wage, making it hard to afford.

As a result, four out of five residents in a city generating 40% of the East African nation’s GDP still depend on a fuel that damages both forests and their health to make daily meals.

“It’s 2019. People have smartphones they can do everything (with), but they are still cooking with charcoal,” said Rodriguez-Sanchez. That “outrageous” situation has to change to avoid environmental disaster, he said.

KopaGas hopes to spur uptake of gas cooking using a pay-as-you-go (PAYG) system it developed.

For an upfront fee of 15,000 Tanzanian shillings ($6.50), a household gets a liquefied petroleum gas (LPG) cooking kit that includes a canister fitted with a smart meter.

The gas supply is unlocked by mobile phone payments and the meter monitors consumption, feeding back data via the Internet of Things (IoT).

KopaGas has signed up 3 500 households for its PAYG service and supplies another 20 000 with traditional gas bottles.

Its services reach about 117,000 people in total, a number it aims to boost to 1 million in Tanzania by the end of 2021.

Rodriguez-Sanchez said the PAYG model needed to be proved at a large scale to attract greater levels of investment.