Stove Battle 2009!

by Daniel Schnitzer

EarthSpark International and members of our implementing partner, the local Non-Governmental Organization (NGO) COREA, perform a water boiling test with four commonly available stoves in Haiti. Three of these stoves use charcoal fuel and one is a kerosene gravity pressure stove. While by no means scientific, we wanted to answer three questions:

1. Which charcoal stove consumes the least amount of charcoal?
2. Which stove is the least expensive to operate?
3. Which stove has the shortest cooking time?

These are important questions to ask for a place like Haiti, especially the rural areas. The most popular stoves are the steel or aluminum stoves shown in the video. They essentially resemble a colander with legs. These stoves are very inefficient. There is no insulation, so heat is radiated out through the sides of the container, and most of the heat in the charcoal is transferred to the pot through conduction rather than through forced, heated air (convection). Either stove costs approximately five US dollars.

You can find more efficient stoves in Haiti. I bought a “recho miracle” or “miracle stove” in the city of Les Cayes for five dollars. Many people in urban areas use these stoves - uninsulated and using conduction, but augmented with a convection chamber - but I was curious whether they were really that much better than the steel and aluminum stoves.

Each stove started with one kilogram of charcoal in its basket. The stoves were tested one after the other so that the same pot could be used. We also used the same amount of water for each stove. We measured the amount of time each stove took to bring the pot of water to just boiling, and then weighed the amount of charcoal left to calculate how much had been consumed. The same process was used for the kerosene stove.

I was very surprised by the results, particularly by how much more efficient the miracle stove was than the other two charcoal stoves. The results are summarized below.

Steel stove:
Fuel consumed: 0.5 kg charcoal
Fuel cost: US$0.08
Time to reach a boil: 15m 16s

Aluminum stove
Fuel consumed: 0.6 kg charcoal
Fuel cost: US$0.10
Time to reach a boil: 20m 37s

Miracle stove
Fuel consumed: 0.3 kg charcoal
Fuel cost: US$0.05
Time to reach a boil: 14m 05s

Kerosene stove
Fuel consumed: 0.13 L kerosene
Fuel cost: US$0.14
Time to reach a boil: 12m 00s

While this test was not scientific, it demonstrates the great differences between the cooking technologies available in most of Haiti. There are several companies around the world manufacturing efficient stoves, and EarthSpark International is working to bring them and other clean energy technologies to the Haitian market. We will also work with domestic suppliers, like the small businesses making miracle stoves in Les Cayes, and Ecole Atelier, which made the kersoene stove, to fabricate efficient stoves here in Haiti. We are hoping to perform a statistically valid experiment with several different stove designs next year to determine which of these stove designs perform the best and which are preferred by consumers.