Marine-inclusive Hybrid Renewable Energy Microgrids for Coastal and Islandic Communities: A Techno-Economic Evaluation

Abstract

The study investigates the potential use of marine renewable energy sources in archipelagic nations, such as the Philippines. A simulation was performed using the Island Garden City of Samal as a case study. An off-grid design is to be simulated for the Samal Island ferry terminal, which connects the Island Garden City of Samal to the mainland of Mindanao in Southern Philippines. This is to avoid reliance on the grid connection that has previously caused the city to run on a diesel generator for months due to a breakage in its submarine cable. A power system that uses a combination of tidal and photovoltaic (PV) is proposed in order to increase reliability of clean energy. For the energy resource, an assessment was conducted using data from weather stations and an acoustic Doppler current profiler deployed on-site. The data was then used in HOMER Energy, a microgrid simulation software, to identify the optimized system. The total load for the system was 18.57 kW, and the design, which had the lowest Net Present Cost (NPC), comprises a 10 kW diesel generator, a 5 kW solar PV array, a 54 kW tidal turbine, 20 kWh lithium-ion (LFP) battery (5 kW). All in all, the proposed system reveals the dominant role of tidal energy, contributing 349,128 kWh/yr. (96.7% of total generation), while solar PV provides 7,770 kWh/yr. (2.2%), and the diesel generator supplies only 4,089 kWh/yr. (1.1%) for backup purposes. This presents the potential utilization of marine renewable energy, enhancing energy resilience in vulnerable island communities while significantly reducing greenhouse gas emissions compared to conventional diesel-only systems.