Marine microalgae as a renewable energy resource: Advances, technoeconomic insights, and commercialization pathways

Marine microalgae are increasingly recognized as a potential feedstock for addressing energy challenges due to their high growth rates, efficient photosynthetic conversion of nutrients into diverse bioactive metabolites. Their biological importance extends beyond their ecological function as primary producers in marine habitats. Other lipids, carbs and proteins are encouraging factors for high-caloric production of biofuels such as biodiesel, bioethanol, biogas and biohydrogen using marine microalgae as feed stocks. Their relevance in this field was further solidified with their ability to capture CO2 and remediate wastewater. Its potential has been recognized; however, there are great hurdles to large-scale commercialization, including expensive production, energy-demanding harvesting methods and technological barriers to bioreactor design. Current challenges highlight the need for new tools and approaches such as genetic engineering, cultivation techniques, and biorefinery advances. This review aims to offer an extensive discussion on the state-of-the-art applications of marine microalgal biomass for sustainable energy production and addresses the present challenges, with an emphasis on future perspectives. The results indicate that, if sufficient research, investment and policy support is provided, marine microalgae could be at the forefront of the transition to a more sustainable and renewable future.