Evaluation of small scale cookstove programs

Abstract

Worldwide, more than three billion people are dependent on the burning of solid fuel for cooking and heating of their houses. Incomplete combustion products emitted into the indoor air form a health threat, especially for women and young children. Air quality is also influenced on a local and global scale and the unsustainable harvesting of fuel wood leads to deforestation. Many programs run worldwide to provide the poorest households with improved cookstoves (ICSs); devices designed to make combustion more efficient and those with chimneys should remove harmful emissions from the indoor environment. Cookstove programs vary considerably in size, scope, type of stove and financial mechanisms. To evaluate the impact of ICS programs, there is a need for evaluation studies involving standard monitoring methods. The feasibility of the various monitoring procedures differs between, on one hand, large scale governmental projects and on the other hand, small scale NGO- or privately funded projects. When a limited number of households is participating in a cookstove program it might be challenging to evaluate the success of it. The resources spent on the evaluation should be proportional to the size and funding of the cookstove program. In other words, an evaluation study needs to be efficient. This thesis focuses on the following question: How to evaluate the success of a small scale cookstove program? In this thesis four evaluation objectives are discussed; adoption and use, indoor air pollution, stove efficiency and health. For each of the objectives an overview is given of study designs and methods used in exemplary studies. On the basis of this overview an advice is given whether a focus on that objective is considered useful for the evaluation of a small scale cookstove program. The main considerations hereby is the required study size for statistically significant data. Basics of the statistics involved in ICS evaluation studies are explained in Appendix A. The measuring methods for the useful evaluation objectives are further described and discussed In Appendix B. To evaluate the success of a small scale cookstove program a focus on indoor air pollution is considered most useful. An ICS can have a large influence on indoor air pollution, so it is likely that a difference will be detectable with a small sample size. The most informative data to obtain is the indoor air PM2.5 concentration. Measuring CO or personal PM2.5 should only be used additional to indoor air PM2.5 measurements. A focus on stove efficiency should be used when a cookstove program was primarily initiated to reduce deforestation. A kitchen performance test that measures fuel use in a household over a number of consecutive days will provide useful data. Focusing on health outcomes is only feasible when questionnaires are used for self-reported symptoms associated with smoke exposure . The preferred study is in all cases the before-and-after design, because it requires the smallest sample size. In this study design measurements are performed in households before and after implementation of the improved stove.