Biomass can be classified as dry biomass (such as wood) or as a wet biomass source such as the organic fraction of domestic waste, agro-industrial waste, sludge and sewage. Thermal conversion or gasification of dry biomass generates energy. Figure 3 summarizes an approximate level of global energy consumption. Nearly 2 billion kg of biomass are burned every day in developing countries. In India in particular, 90% of primary energy consumption comes from biomass in rural areas (wood: 56%; crop residues: 16%; manure: 21%). Combustion from these sources results in high concentrations of respirable particles, gases including CO, SO2, nitrogen oxides and toxic compounds such as benzene and formaldehyde [23]. Wet biomass is less suitable for thermal conversion. Biotechnological processes are involved in which reactions are catalyzed by microorganisms in an aqueous environment at low temperature and pressure. Aquatic biomass exhibits easy adaptability to grow in different conditions and has enhanced CO2 fixation accompanied by low nitrous oxide release. Some microalgae biomasses are considered as a better alternative renewable energy source, terrestrial or aquatic (Botryococcus braunii) (Fig. 1m). . Considering the oil content of many microalgae (Table 2), energy harvesting from biomass can be easily implemented on a large scale. The photosynthetic efficiency of aquatic biomass is much higher (6–8%) than that of its terrestrial counterpart (1.8–2.2%) [13]. Additionally, aquatic biomass exhibits easy adaptability to grow in different conditions, whether in fresh or marine water, or in a wide pH range. This makes aquatic biomass more adaptive or better CO2 fixation to enable high biomass production. The only feasible methods for large-scale production of microalgae are tubular photobioreactors [19] and open ponds [20]. Extensive studies have been carried out for the cultivation of different marine microalgae using various culture systems, including open ponds and various types of closed photobioreactors (21, 22). Since several articles already discussed large-scale production, this article did not focus on these issues. Biomass for power generation has been recognized as an important component of India's renewable energy agenda and this is reflected in the priority given to it by the MNES. There are niches with substantial potential for the use of biomass for electricity generation, e.g. bagasse cogeneration in sugar mills, decentralized diesel cogeneration systems based on gasifiers in South India and biomass waste from agricultural operations or agro-industries in concentrated geographic pockets [23]. An additional biomass/CHP power generation capacity of 115 MW in six states was created in the country during the year, reaching a cumulative power generation capacity of 727 MW..