Cooking Efficiently: 3stone fires, biomass hobs ...
Mar 11, 2015 · The Thermal Efficiency of a Threestone Fire. At the heart of the problem lies the low thermal efficiency of traditional cooking methods. For threestone fires, thermal efficiency is stated to be as low as 10 to 15%. [ 1 ] [ 2] In other words: 85 to 90% of the energy content in the wood is lost as heat to the environment outside the cooking pot.