- Clean cooking technologies and fuels have been cited as a viable way to slow climate change and reduce the health and environmental impacts associated with traditional cooking devices used by 40% of the world. While engineers in the Design for Development sector have created hundreds of stove designs that perform well in laboratory settings, quantifying their impact in real-world households has been a greater challenge. Both technical performance and user adoption are context-specific metrics that need to be monitored directly in households for practitioners to understand actual impact and secure results-based financing or reevaluate less successful projects.
While sensor-based monitoring has become increasingly common in the clean cooking sector to capture long-term, relatively objective data, one glaring performance metric not yet captured by these methods is fuel use, which is linked to deforestation, time expended towards firewood collection or purchase, and emissions. This gap motivated the development of the Fuel, Usage, and Emissions Logger (FUEL), a wireless logging load cell that monitors fuel weight data over time. These data can be aggregated to determine long-term fuel use and savings when compared to a baseline stove through a developed algorithm, and used in equations to determine emissions, carbon credits, and averted Disability Adjusted Life Years (aDALYs).
The purpose of this research was to develop, evaluate, and validate the FUEL system in terms of usability, technical feasibility, and accuracy. Assessment methods included an interdisciplinary combination of sensor-based monitoring and ethnographic techniques, such as semi-structured surveys, informal interviews, and participant observation. A preliminary evaluation was conducted in Honduras with four households in May 2017, and later scaled in Uganda in August 2017 and July 2018 to 85 and 44 households, respectively, to log for 30-45 days. Following this, fuel consumption as measured by FUEL was compared to that of the Kitchen Performance Test, the current accepted manual method to measure fuel consumption, to validate measurements. Validation was conducted in Uganda and Burkina Faso for four days each between July and August 2018, in 20 and 10 households, respectively. A combination of wood, LPG, and charcoal stoves were monitored, and the majority of households in the Burkina Faso study were stacking at least two of the three fuel types.
Preliminary results point to user acceptance of the FUEL system in the context of the study villages in northern Uganda. Analysis indicated that the FUEL is a viable method to report key metrics of interest, including per-capita measures of fuel use per day or longer, cooking events and duration, and extrapolated average firepower and climate impacts. Results also inform frameworks for how to integrate sensor-based and ethnographic methods in Design for Development settings to assess technology usability. The two comparison studies to validate the FUEL showed that FUEL data closely match those of the Kitchen Performance Test on an aggregate level, captured several sources of potential error with both methods, and indicated that FUEL can be a cost-effective option over longer monitoring durations.
These cross-cultural studies have provided evidence of the efficacy and usability of the FUEL system and pave the way for future work in the area of global fuel consumption measurements. Broadly, this system can be used for monitoring a wide variety of stoves and fuel types, and for additional applications such as agricultural products or crop residues to understand impacts of agricultural practices. It is hoped that the FUEL system can serve as a useful and usable tool to more objectively monitor real-world fuel use, and ultimately support increased accountability, transparency, and impact of the development sector.