A multi-approach framework for developing feasible, viable, and sustainable hybrid energy systems in remote areas: The case of Con Dao island in Vietnam

In remote communities, hybrid energy systems are increasingly used to improve the reliability and renewability of power supply. The techno-economic analysis is often used to develop these promising energy systems, ignoring some performance indicators and environmental factors. This study proposes a multi-approach framework for developing operationally feasible, economically viable, and environmentally sustainable hybrid energy systems in remote areas. A case study is conducted on Con Dao Island in Vietnam to supply its electricity demand using six on-grid and off-grid hybrid energy systems. After finding the best techno-economic configurations of the six developed systems, they are subjected to multi-approach analysis and exhaustive comparison using a set of performance, economic, and environmental indicators. An off-grid hybrid energy system comprising photovoltaics, wind turbines, lead-acid batteries, and diesel generators has the lowest net present cost (109.7 million USD) to supply the predicted island's electricity consumption (with a total on-site electricity generation of 184.1 GWh/ yr). However, this off-grid system indicates the highest excess energy fraction (55%), while the on-grid systems with the ability to export excess energy to the grid have no excess energy fraction. In terms of eco-friendliness, an on-grid hybrid energy system consisting of a high level of photovoltaics and wind turbines shows the best results, with a negative total environmental impact and CO2-eq emissions. This on-grid system shows the best cost of energy (0.1 USD/kWh) with approximately 450% less total environmental impact than the best off-grid system investigated, offsetting about 48.2 kilotonnes of CO2-eq/yr by exporting net emission-free electricity. Overall, the proposed framework can assist decision-makers in finding feasible, viable, and sustainable hybrid energ y systems.