Feasibility study of on/off grid large-scale PV/WT/WEC hybrid energy system in coastal cities: A case-based research

In this study, according to the potential of available renewable resources in coastal areas, a hybrid system is proposed. The generalizability of the results of this study to other areas with different economic conditions and potential of energy resources is estimated through sensitivity analysis. Besides, the effect of the wave energy converter on the hybrid system is evaluated as a novel approach in sustainable power generation. Furthermore, it is attempted to measure the optimal distance from the power grid for economic development of stand-alone systems. The results demonstrate that the grid-connected system with 0.093–0.139 $/kWh cost of energy is more cost-effective compared to off-grid system with 0.136–0.182 $/kWh for large-scale demand. Employing wave energy converter not only leads to a more uniform power generation profile, but also reduces the need for batteries in hybrid energy system. However, using this device in areas with lower wave potential can significantly increase the expenses. Also the results reveal that the breakeven distance is reduced from about 300 km to less than 40 km by decreasing the demand from 20 MW to 1 MW. Moreover, it is concluded that rising the grid tariffs can be an effective policy to improve the renewables economic efficiency.