State-of-the-Art in algal biofuel research: Waste- algae as a sustainable energy solution

The rapid urbanization and industrialization of the 20th century have accelerated the depletion of natural resources while significantly contributing to greenhouse gas emissions, global warming, and a surge in waste generation. This has shifted global research efforts toward alternative renewable and clean resources as well as less waste generation. Waste to energy and other products has become the prime goal in many of research works. As energy sector plays an elemental role in all the developmental sectors, renewable cum clean energy source is of prime necessity. Algal fuel, in this situation, has gained attention due to the rapid growth rate of algae and their high oil content, making them a potential candidate for sustainable energy. Algae ' s photosynthetic efficiency surpasses that of terrestrial plants, exceeding 10% compared to less than 0.5%. However, the high production cost of algal oil remains a significant barrier to its commercialization. Economic analyses suggest that a reduction in the price of raw materials used and processing could reduce these costs and make algal biofuels more competitive with fossil fuels. Hence, waste algae emerge as a viable and cost-effective alternative. Abundantly available in countries like India, waste algae address environmental issues like eutrophication while providing an inexpensive feedstock for biofuel production. Although their lower oil content and compositional variability pose challenges, strategic research and optimization could unlock their potential, transforming waste algae into a cornerstone of renewable energy solutions. With its vast availability at no cost, waste algae in India could revolutionize the biofuel sector, offering a pathway toward affordable and sustainable energy for the future.