Mozambique relies on wood biomass for meeting its household energy demand. This has been for long referred to as one of the main causes of the ongoing deforestation, mainly around the large cities and village. On the other hand, the country produces large quantities of agricultural crops residue which are still not being appropriately and integrally used as additional source of energy, especially for communities in the countryside where these residues are generated. Cashew nut shells (CNS) are among those residues. This kind of feedstock is said to be of high energy content. However, its utilization as energy source within the country is still poor.In Mozambique, 90% of the households depend on biomass for cooking. Biomass has already emerged in the renewable energy area as one of the promising candidates for the future energy source. Historically, biomass has been a major source of fuel from the existence of making rapid urbanization, but widespread use of fossil fuels in the industrialization has relegated it to a minor source of energy. The CNS Gasifier Stove developed has a thermal efficiency of 35.5% and an energy output of 2.19 kW. The corresponding values for LPG stove and Kerosene stove are 53.53% (0.69 kW) and 39.3% (0.6 kW), respectively. Though the use of CNS gasifier as a fuel is less efficient than the aforementioned one, with the rising oil prices and the search for alternatives to contemporary cooking fuels, it is still a viable alternative in this comparison.