Pollutant Emissions and Energy Efficiency under Controlled Conditions for Household Biomass Cookstoves and Implications for Metrics Useful in Setting International Test Standards

TLDR

Realistic metrics and consistent test practices for household biomass cookstoves are needed to develop international standards and benchmark emissions and energy efficiency across stove types. The study aims to recommend useful metrics for setting international standards based on laboratory‑controlled test results. The authors tested 22 cookstoves burning six fuel types at two moisture levels under the Water Boiling Test protocol, continuously monitoring emissions, fine particle mass, power, energy efficiency, and fuel use to derive emission factors. The advanced cookstove achieved the lowest PM2.5 emissions (74 mg MJ⁻¹) and the highest thermal efficiency (53 %) compared with the 3‑stone cookfire (700–1400 mg MJ⁻¹ and 14–15 %).

Abstract

Realistic metrics and methods for testing household biomass cookstoves are required to develop standards needed by international policy makers, donors, and investors. Application of consistent test practices allows emissions and energy efficiency performance to be benchmarked and enables meaningful comparisons among traditional and advanced stove types. In this study, 22 cookstoves burning six fuel types (wood, charcoal, pellets, corn cobs, rice hulls, and plant oil) at two fuel moisture levels were examined under laboratory-controlled operating conditions as outlined in the Water Boiling Test (WBT) protocol, Version 4. Pollutant emissions (carbon dioxide, carbon monoxide, methane, total hydrocarbons, and ultrafine particles) were continuously monitored. Fine particle mass was measured gravimetrically for each WBT phase. Additional measurements included cookstove power, energy efficiency, and fuel use. Emission factors are given on the basis of fuel energy, cooking energy, fuel mass, time, and cooking task or activity. The lowest PM2.5 emissions were 74 mg MJdelivered–1 from a technologically advanced cookstove compared with 700–1400 mg MJdelivered–1 from the base-case open 3-stone cookfire. The highest thermal efficiency was 53% compared with 14–15% for the 3-stone cookfire. Based on these laboratory-controlled test results and observations, recommendations for developing potentially useful metrics for setting international standards are suggested.