News & events

  • Home
  • News & events
Back
2025 January 08

Institutional cooking with pellets in Rwanda – a Pilot Project

Summary of Results, by Paul Prauhart, Christian Rakos (World Bioenergy Association) Thomas Roelofs, René van der Velden (BioMassters)

In September and October 2024, the World Bioenergy Association in collaboration with BioMassters Ltd, a company registered in Rwanda, carried out school cooking pilot project, replacing firewood use by pellets made locally from wood waste. The pilot at EPA St. Michel in Kigali added pellet burners to the existing ‘muvelo’ stoves, and therefore changed the fuel source to heat the cookstoves, but not the cookstoves themselves. Extended Kitchen Performance Tests were conducted to compare the fuel demand of conventional cooking with firewood with the fuel demand when stoves were retrofitted with pellet burners.

The pilot resulted in several significant benefits compared to existing and other school cooking methods:

  • Significantly reduced wood use
  • A smokeless kitchen
  • Significantly lower investment cost vs conversion to LPG and electric cooking
  • Similar operational fuel costs (vs firewood) for pilot school
  • Significant improvement in convenient for kitchen staff

 

Impact of conversion on fuel use
The pilot showed that the amount of fuel used by the pellet burner was less than half (in terms of mass) compared to firewood. This result was consistent for several different dishes cooked in the school. Also, the variation of fuel needed per dish was significantly lower for pellet operation.

When considering the firewood needed to dry the wood wastes for pelletization the total reduction of firewood demand was 83%, a figure that could be improved to 92% with a more efficient drying system for pellet production.

Impact of conversion on smoke generation
The conversion let to a drastic reduction of smoke generation in the kitchen. While precise quantitative measurements require very expensive measurement equipment the used measurement device gives a reliable comparison and showed impressive improvements. Comparative measurements of chimney emissions could not be performed for technical reasons – however tests in similar situations performed by the authors revealed a reduction of carbon monoxide emissions by two orders of magnitude (a factor of 100) when replacing firewood operation of a cookstove with pellet operation.

Impact of conversion on cost
The comparison of cooking costs with pellets with firewood proved difficult as costs of firewood seemed to differ considerably between different schools – partly due to local price variations but also due to very unprecise data (e.g. measurement of quantity in truckloads without further specification). The comparison with LPG use and electric cooking showed significant price advantages in terms of fuel costs but depend also on applicable electric tariff and specific pricing for LPG supply that were not available. An extended pilot is panned to be conducted to validate the running cost of pellet cooking at different types of schools.

The conversion costs to pellets for a cookstove amounted to 3,000€. Data comparing this to the conversion cost to LPG use or electricity use were not available.

Other impacts of conversion
Cooks in the school perceived the conversion to pellets as great improvement. The power of the pellet burner can be controlled very easily, there is no smoke in the kitchen and the effort of refuelling is reduced from constant refuelling with firewood to filling of the pellet storage bin once a week with a few bags of pellets. The school wanted to continue cooking with pellets after the pilot test was finished and is doing so ever since.

In summary pellet cooking provided a solution that is based on local renewable resources, that is not dependent on imports, foreign exchange or volatile prices and that is safe, affordable and clean.