New prospects for PV powered water desalination plants: case studies in Saudi Arabia

Abstract

AbstractIncreased water demand and increased drought episodes in the Middle East and other regions necessitate an expansion in desalination projects and create a great market opportunity for photovoltaics (PV). PV‐powered desalination has previously been regarded as not being a cost‐competitive solution when compared with conventionally powered desalination; however, the decline in PV costs over the last few years has changed this outlook. This paper presents up‐to‐date performance and cost analysis of reverse osmosis (RO) desalination powered with PV connected to the Saudi Arabian grid. Reference cases include relatively small (i.e., producing 6550 m3 water per day) and large (i.e., 190 000 m3/day) desalination plants using seawater at a salinity of 40 000 ppm. We used data from a King Abdullah University for Science and Technology presentation and Hybrid Optimization Model for Electric Renewables 2.81 Energy Modeling Software (HOMER Energy LLC) in tandem with Desalination Economic Evaluation Program 4.0 (International Atomic Energy Agency) desalination software to analyze the techno‐economic feasibility of these plants. The first phase of our work entailed a comparison between dual‐axis high concentration PV (CPV) equipped with triple junction III/V solar cells and CdTe PV‐powered RO systems. The estimated levelized cost of electricity from CPV is $0.16/kWh, whereas that from CdTe PV is $0.10/kWh and $0.09/kWh for fixed‐tilt and one‐axis tracking systems, respectively. These costs are higher than the price of diesel‐based grid electricity in the region because diesel fuel is heavily subsidized in Saudi Arabia.In the second phase, we determined the cost of producing desalinated water from the two RO plant sizes powered with CdTe PV. Assuming that the grid acts as zero‐loss storage, the total water cost ranges from a high cost of $1.39/m3 for the small RO plant coupled with latitude‐tilt, fixed PV to $0.85/m3 for the large RO plant coupled with optimally positioned one‐axis tracking systems; these PV power plants would displace 1 158 987 and 33 579 763 l of diesel per year, respectively. Furthermore, the corresponding savings in diesel subsidies enabled by PV are $1.5m and $43.2m per year. Applying these savings to the PV system calls for a levelized cost of electricity of $0.21/kWh, justifying a feed‐in‐tariff at this level. The avoided CO2 emissions by displacing diesel fuel would be 3115 and 90 241 tonnes per year for the small and large Photovoltaics Powered Reverse Osmosis Water Desalination (PV‐RO) plants, respectively. On the basis of the results of this study, we infer that there are great business prospects associated with large deployment of PV‐RO plants in the greater Middle East, and we estimate the reduction in regional CO2 emissions from such deployment. Copyright © 2015 John Wiley & Sons, Ltd.