Industrialization and rapid development surged the energy demands and landfill usage required to cater to for the increase in waste disposal. Organic wastes valorization can alleviate the adverse impacts on the environment and can convert wastes to value-added products. Organic waste varies in availability and composition, which can be generalized to carbon-rich and/or nitrogen-rich. The carbon-to-nitrogen (C/N) ratio is one of the significant factors for biomethane production and must be considered during system design. This research proposed a numerical framework for targeting waste-to-energy system taking into consideration the inconsistency of daily organic wastes availability (C/N ratio), volatile solid percentage (VS%), and total solid percentage (TS%). The methodology from previously established Electric System Cascade Analysis (ESCA) was adopted and applied to design the waste and product storage. The developed methodology implemented in a case study comprises of 50 houses with a total energy demand range from 1,095 to 1,290 kWh/d. A 49.01 m3 biogas storage was equipped into a biomethane energy system with 115.93 m3 CH4 daily production to satisfy the energy demand. The identified organic wastes storages capacity was 2,695.17 m3 for swine manure and 416.17 m3 for rice straw.