There are different methodologies available, depending on which resource you measure, who uses it (e.g. households vs. companies), what data is already available, etc. The two key approaches include:
1) REVIEW OF AVAILABLE DATA: Depending on who your target group is and which resource you monitor, you might be able to take advantage of already available data. For example:
- a company or organisation which developed / promotes a certain technology (e.g. a solar lamp) has reliable and up-to-date data on how much of a given resource the technology saves when used
- companies having records of how much of a given resource they used
- electric metres (or electricity bills) providing data on electricity consumption
This approach is much easier; however, such data is often unavailable or might not be sufficiently reliable.
2) ON-SITE MEASUREMENTS involve measuring the amount of a given resource used by a sample of households (or other target groups) within a certain period (e.g. 24 or 72 hours) in a way that can be generalised to a longer period and larger population. As much as possible, the measurement should follow an internationally recognized protocol (see an example of Kitchen Performance Test (KPT) protocol and other protocols included at this site).
For example, if you want to measure in the target areas the consumption of firewood used for cooking, you should:
- secure measuring equipment (scales)
- prepare written guidance on the entire measurement process that the enumerators / measurers can follow and train them in its use (take advantage of guidance included in the KPT protocol)
- prepare two randomly selected samples of households with similar socio-economic conditions and household size (read this KPT protocol and this Appendix 3 for guidance on sampling) – those who use the project’s technology that was supposed to reduce firewood consumption (e.g. a fuel-efficient stove or a biodigester) and those who do not.
- determine the duration of measurement (e.g. 72 hours)
- agree with the selected households on:
- their agreement to participate in the measurements (they must understand why they are asked to participate and that the results will not bring them or deprive them of any benefits)
- when the measurement will take place (this must be a ‘normal’ day when the household is not cooking significantly more or less than usual)
- what firewood they should use within the measured period (together you should set aside a specific stock of firewood that is the same type of firewood that the household usually uses)
- how should the firewood be used (it should be used in the same way as on any other ‘normal’ day)
- leaving any unused firewood from the agreed stock pile in place
- measure the weight of the firewood allocated for the given period
- after the monitored period is over, measure the weight of the unused firewood
- determine the weight of the firewood that was used during the monitored period by households who 1) used the firewood-saving technology and 2) those who did not use it
- calculate the difference in firewood consumption between these two groups of households
- use the data on the amount of firewood saved per day per household (that used the promoted firewood-saving technology) to calculate the total amount of firewood saved per household during the period stated in your indicator
- to calculate the indicator’s value, divide the total amount of firewood saved per household during the measured period by the total number of households using the firewood-saving technology
A similar process can be used to measure the usage of other resources, such as kerosene or charcoal.