Findings from a field study conducted in Rwanda designed to test the performance of a new cookstove showed that units with compressed wood pellets cut air pollution by about 90% for a range of contaminants.
“There have been numerous attempts to develop cleaner cookstoves for use in developing countries, but while they’ve often done well in lab testing, they've had disappointing performance when tested in real-world conditions,” said Andy Grieshop, an associate professor of environmental engineering at North Carolina State University. “However, we found that the pellet-fed stoves performed well in the field. We saw drastic cuts in pollutant emissions.”
The pellet-fueled stoves rely on battery-powered fans to burn the pellets efficiently, reducing pollutant emissions. They come with solar panels for recharging the batteries, making long-term use feasible in areas where plugging a battery charger into the wall is not feasible.
The researchers tested for a range of air pollutants, including fine particulate matter (PM), carbon monoxide, and black carbon, a major contributor to climate change. A large fraction of global black carbon emissions comes from heating and cooking in homes.
Mean reduction in PM emissions from pellet-fueled stoves was 97% compared to wood fires and 89% compared to charcoal cookstoves. The pellet-fueled stoves are also the first cookstoves that have met the International Organization for Standardization’s (ISO) highest standard—Tier 5—for carbon monoxide emissions. The stoves also met stringent emission rate targets for carbon monoxide set by the World Health Organization, though they fell slightly short of the PM emission target.
While these results are promising, the real challenge will be whether the pellet-fueled stove concept can be scaled up to meet the demands of millions in low- income regions. Test results showing how effective the pellet-fueled stoves are at reducing air pollution are new, but the concept of introducing new cookstoves is not.