By Douglas Barnes and Keith Openshaw
|Kerosene Lamps and Stoves, Hyderabad, India by D. Barnes|
- Cost of the stove;
- Lifetime of the stove;
- Efficiency of the stove;
- Price of fuels used burned by the stove including wood or other biomass fuels;
- Fuel collection hours for biomass fuels;
- Quantity of fuel consumed in the household per month; and
- Average wage of agricultural workers.
For much more continue below....
To calculate the comparative cost of cooking after assembling the data, there are several different steps. First, the quantity of fuel typically used per month should be multiplied by the price of the fuel. This gives the monthly cooking costs. Generally traditional stoves are most commonly used in developing countries making it difficult to calculate cost for improved stoves. The fuel cost for an improved stove can be estimated by adjusting the cost of using a traditional stove according to the fuel efficiency improvement of the alternative stove. If a stove involves a 50% reduction in fuel consumption, then adjust the typical fuel consumption for a traditional stove by one-half. Of course it is better to use the actual consumption for a family using an improved stove, but this is often not available.
For collected fuels, there are two ways to establish the value of fuel collection. The market price can be used if there is local market for wood or other biomass fuels. However, if there is no local market for such fuels, then it is quite legitimate to multiply the average fuel collection time per month times the local agricultural wage rate. One issue that comes up often when I mention this technique is that people question whether the agricultural wage for a typical hour can be applied to fuel collection. The underlying assumption is that people in rural areas have time on their hands. However, this is a legitimate method, because this wage rate is generally established by a market. Also, in my many travels in rural areas of developing countries I have not found women with much free time. They are generally working from dawn to dusk.
Interestingly, cooking with an open fire is the most expensive form of cooking with wood. Once you spread the price of an improved stove over its lifetime, the actual stove costs are quite low and completely overshadowed by the value of saved biomass or reduced collection time. This might suggest that in addition to the value of convenience and cultural cooking practices, a key to promoting improved stoves is to spread out the relatively unaffordable initial purchase costs of the stove. Once this is done the next generation wood stove has the lowest expenses for cooking compared to all other stoves. In fact, cost savings compared to an open fire can be as high as 40%. Even biogas stoves with their large initial costs are quite competitive after spreading the costs of the stoves over their lifetime.
We know that petroleum fuels are preferred in urban areas because they are convenient and easy to use, but they are more expensive than biomass fuels. By contrast in rural areas incomes are often low so people continue to use the less expensive biomass fuels. We often discount helping such households thinking that they will eventually catch up with the rest of the developed world and switch to petroleum fuels. But the cost differentials are quite high, and we are ignoring a quite attractive alternative that involves using the same biomass fuels they collect everyday in more efficient and modern ways.
After getting several requests for the background data, please click on the attached link for the Notes and Assumptions for Comparing Cooking Costs.
Were you surprised with any part of these findings? Would additional research and development and expansion of markets make these new technologies even more attractive and affordable?
Answer the quiz or comment below.