In this paper, double slope solar still has been analyzed by incorporating N identical partially covered photovoltaic thermal (PVT) collectors under optimized condition to assess the enhancement in energy metrics. Number of collectors, mass flow rate and water depth of N identical partially covered PVT flat plate collector (N-PVT-FPC-DS) have been optimized for climatic condition of New Delhi. Subsequently, annual distillate output, energy, exergy, energy metrics, cogeneration efficiency and cost of distillate output have been computed for the proposed N-PVT-FPC-DS at 0.14 m water depth. Results obtained have been compared with results reported by previous researchers and it has been concluded that the proposed N-PVT-FPC-DS performs better than double slope solar still incorporated with N identical PVT compound parabolic concentrator collectors (N-PVT-CPC-DS) and conventional double slope solar still (CDSSS) on the basis of energy metrics and cost of distillate output. The exergy based energy payback time is lower by 74.66% and 62.62%; energy production factor is higher by 43.30% and 38.14%; life cycle conversion efficiency is higher by 48.57% and 48.57% and cost of distillate output is lower by 35.37% and 4.88% for the proposed N-PVT-FPC-DS than N-PVT-CPC-DS and CDSSS respectively. (C) 2016 Elsevier Ltd. All rights reserved.