Cooking Stoves: Curbing Disease and Cutting Climate Change

Around the world, nearly 3 billion people cook their meals using open fires or simple stoves fueled by biomass (animal dung, crop waste or wood), coal or kerosene, according to the World Health Organization. And each year, close to 4 million people die prematurely from illnesses attributable to such polluting and inefficient cooking practices—that’s more than from HIV, malaria and tuberculosis combined.

To make matters worse, a large fraction of global black carbon (sooty particle) emissions—a powerful climate change pollutant—comes from cooking and heating in homes.

That’s why a 2019 field study conducted in Rwanda is providing some good news and hope for the future of the climate and people’s health. A new cookstove design, which makes use of compressed wood pellets, has been found to reduce air pollution by about 90 percent for a range of contaminants associated with health problems and to lessen greenhouse gas emissions.

But, how do we get these cookstoves delivered and convince people to use them? Turns out, there’s positive news on that front, too.

Pellets prove promising

Globally, household cooking is responsible for 12 percent of ambient, fine particulate matter and gaseous pollutants that contribute to adverse health. Mainly, it’s women and young girls who are affected, since they do the majority of the cooking and fuel-gathering. It’s estimated that rural women spend an average of three hours a day collecting wood, resulting in widespread deforestation and leading to ever-increasing erosion and fatal mudslides.

In Rwanda, firewood accounts for at least 86 percent of energy consumption and is the primary cooking fuel for 98 percent of rural households. In the Rwanda-based study published in the journal Environmental Science and Technology in April 2019, North Carolina State University researchers stated that pellet-fueled stoves that rely on battery-powered fans to burn the pellets efficiently reduce pollutant emissions. The stoves come with solar panels for recharging the batteries, making long-term use feasible in areas where plugging a battery charger into the wall isn’t an option.

To reach their conclusion, the researchers monitored air emissions when people in Rwanda prepared food using three different methods: conventional wood fires, which are common in rural areas; conventional charcoal-burning cookstoves, prevalent in urban areas; and the new pellet-fueled cookstoves. They tested for a range of air pollutants, including black carbon, carbon monoxide and fine particulate matter.

The mean reduction in particulate matter emissions from pellet-fueled stoves was 97 percent compared to wood fires and 89 percent compared to charcoal cookstoves. The only exceptions the scientists found to these emission cuts were when a pellet stove was used improperly.

The stoves are leased for free, in return for buying or trading sustainably harvested and collected wood for the fuel pellets. In Rwanda, the cost of the pellets is less than the cost of the charcoal people buy for their cooking needs. Right now, the fuel pellets are made using sawdust waste from timber operations. How scalable that will be in the future is not known.

Rebates render results

Sometimes, global health efforts to design and deliver improved cookstoves don’t always catch on. Experience has shown that those who live in poor households in rural settings will rarely pay for or use new types of stoves, likely because of constraints imposed by culture, geography or markets. So, researchers from Duke University set out to discover whether addressing these barriers to adopting the stoves would increase the demand.

In a field test conducted over a period of five years, which included nearly 1,000 households in 97 geographically distinct villages in India, the Duke researchers undertook a three-phase study: diagnose, design and test.

In the first phase, the researchers analyzed existing research on improved cookstove adoption and looked at sales across different potential study communities, which provided insight into both demand- and supply-side barriers to adoption. They then conducted focus groups in more than 100 households in 11 rural Indian communities in order to understand local cooking practices, perceptions of different stoves and preferences for stove features.

In the design phase, the scientists worked with local organizations to implement eight, small pilot programs in three different settings. These included small-scale testing of various supply-chain issues, such as home delivery, rebates and financing, and choices of various stove technologies.

In the third phase, they conducted a field experiment to determine whether the combination of an upgraded supply and marketing promotions would lead to increased adoption of improved cookstoves.

Results showed that more than half of the intervention households bought an improved cookstove compared with zero purchases in the control villages. The demand was very price-sensitive; and the largest rebate, 33 percent of the retail price, led to the largest purchase rate, 74 percent. In the areas that only had an upgraded supply chain and promotions without rebates, there was a 28 percent increase in ownership of the improved cookstoves.

Published in the Proceedings of the National Academy of Sciences of the United States of America in July 2019, the Duke University report stated that adopting some common business practices—such as performing a careful market analysis, upgrading the supply chain and offering price rebates—can increase purchase and adoption of improved cookstoves by as much as 50 percent.

A carbon-offset project for cooks—and noncooks

In Rwanda, almost two-thirds of the forests have been lost since the 1960s, and demand for biomass energy continues to be a major driver of deforestation. Therefore, increasing energy efficiency through the use of improved cookstoves is fundamental for ensuring that energy needs are met in a sustainable way without compromising the integrity of the remaining forests.

To aid in that effort, Natural Habitat Adventures is sponsoring a carbon-offset project that provides innovative home cookstoves to communities throughout Rwanda. By employing these new stoves, locals will use 70 percent less firewood compared with traditional stoves, decreasing rampant deforestation in central Africa. The new stoves also free up approximately 2 million hours of time required to collect wood, allowing people to spend more time on income-generating activities.

The short video below, titled Tea Time, will familiarize you with such energy-efficient stove initiatives. Whether you have talent as a cook or not, this is one food-preparation project you contribute to as a Natural Habitat Adventures traveler.

Here’s to finding your true places and natural habitats,

Candy