For the organic waste disposal, rotary use of composters is common and frequently employed. Additionally, the amount of energy adopted to move organic waste is a key factor that should be highly considered when designing and manufacturing a composter machine and picking up the motor engine. Moreover, the power of promoting organic substance can be represented by compost size, operating parameters (sunshine, humidity...) and based on a simplified organic waste mass model generated by regression approximation mechanical equations with satisfactory results and precision. Finally, the reliable efficiency of this model is measured by particular data on an industrial rotary composter system.