AbstractThis paper determines the optimal capacity of solar photovoltaic (PV) and battery energy storage (BES) with novel rule‐based energy management systems (EMSs) under flat and time‐of‐use (ToU) tariffs. Four schemes are investigated based on the combinations of flat and ToU tariffs for buying and selling the electricity: (1) Flat‐Flat, (2) ToU‐Flat, (3) Flat‐ToU, and (4) ToU‐ToU. For each scheme, two configurations are evaluated: (i) PV only, and (ii) PV‐BES. The optimization of the grid‐connected household is evaluated based on one‐year realistic data. An uncertainty analysis is presented based on the variations of insolation, temperature, and load. Sensitivity analyses are implemented based on the average daily load, the grid constraint, and the costs of PV and BES. The operational analyses for 48 h in summer and winter are carried out to evaluate the dynamic performance of the systems for high and low solar insolation. The effectiveness of the proposed model is verified by comparing the results with that of common EMS based on the net metering scheme. It is found that the COE of the proposed EMS for a PV‐BES house with ToU‐Flat scheme (as the best option) is 2 ¢/kWh lower than that of the net metering scheme.