Investigations on energy efficiency of biomethane/biocrude production from pilot scale wastewater grown algal biomass

•Algal consortium cultivated outdoor in wastewater without using external energy.•Average biomass productivity of 3.48 ± 0.44 gm−2 d−1 under natural conditions.•Biomethane vs biocrude yield for different energy conversion routes compared.•Net Energy Ratio (Hydrothermal liquefaction) > Net Energy Ratio (anaerobic digestion).•Existing bottlenecks in algal biofuels feasibility discussed with possible solution.