aSchool of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India, bDepartment of Energy, Tezpur University, Tezpur 784028, Assam, India cDepartment of Scientiļ¬c and Industrial Research, Ministry of Science and Technology, Government of India, New Delhi 110016, India dCentre for Energy Studies, Indian Institute of Technology Delhi, New Delhi 110016, India eeEnergy and Wetland Research Group, Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560012, India fDepartment of Biological and Agricultural Engineering, University of California Davis, California 95616, USA *Corresponding author:cestvr@ces.iisc.ernet.in