Microalgae are a diverse group of microorganisms that grow through autotrophic, mixotrophic, and heterotrophic modes, with light availability playing a crucial role in metabolic processes. Cultivated in open ponds, closed photobioreactors, and fermenters, microalgae have promising applications in food, feed, pharmaceuticals, cosmetics, and biofertilizers, as well as potential roles in bioremediation. However, high production costs remain a major barrier to large-scale commercialization. In temperate regions, seasonal variations in temperature and light availability introduce additional challenges, necessitating adapted cultivation strategies compared to the more stable conditions found in tropical regions. This chapter examines the challenges of large-scale microalgal cultivation in temperate climates, focusing on advancements in cultivation techniques, product development, and strategies to enhance environmental, economic, and social sustainability, thereby supporting the expansion of the blue bioeconomy.