The formula to calculate the maximum power in a biomass cookstove is:

\[ P_{max} = \frac{M_f \cdot C_p \cdot (T_f - T_i)}{T_c \cdot \xi} \]

Where:

• \(P_{max}\) is the maximum power in KCal/hr.
• \(M_f\) is the mass of food in kilograms (kg).
• \(C_p\) is the specific heat of food in KCal/kg-C.
• \(T_f\) is the final temperature of food in degrees Celsius (C).
• \(T_i\) is the initial temperature of food in degrees Celsius (C).
• \(T_c\) is the cooking time in hours (hr).
• \(\xi\) is the thermal efficiency of the stove (decimal).