Techno-economic perspective of a floating solar PV deployment over urban lakes: A case study of NUST lake Islamabad

Abstract

Water bodies like small lakes, canals, and rivers in urban areas serve to be a way forward to deploy photovoltaic technology with no constraints to involve land procurement. This article aims to estimate the potential deployment of a floating photovoltaic system on an urban lake site to assess its scope and compare it with a similar specification on-ground photovoltaic system. System Advisor Model (SAM) has been used for techno-economic analysis of a site in Pakistan. The technical analysis involves observing the effect of real time temperature drop and calculation of water reduction efficiency for FPV systems. The economic parameters like net present value (NPV) and payback period are used to judge the economic feasibility of the floating photovoltaic deployment project. The floating photovoltaic deployment in an urban area is subject to soiling as the water reservoir being used exists in an area close to or within the city boundaries. The required cleaning water costs a one-time extraction rate of $1435, while for a floating photovoltaic system, the extraction cost is estimated to be $1.35. Under standard temperature conditions (STC) one-year capacity factor turns out to be 0.70% more, producing an additional energy yield of 64 kWh/kW for lake scenarios when a 10 °C temperature drop is considered. The total power potential for the entire NUST Lake turns out to be 4.47 MW. A 1 MW FPV system in NUST lake would result in a water reduction efficiency of 11.6%/year. Under standard temperature conditions, the net present value for the on-ground system becomes negative while it remains optimistic for the floating photovoltaic system as no land costs are required. Similarly, once the land cost is included in the feasibility analysis, the payback period for the on-ground system goes beyond 15 years which is only 5.37 years for a floating photovoltaic system signifying the economic feasibility of the floating photovoltaic project.