Techno-economic analysis on the production of domestic water using solar-driven membrane seawater desalination device in the Philippines

Abstract

This study investigates the technical design and economic assessment of an industrial plant that produces 160 m3/day of domestic water using solar-driven membrane seawater desalination technology. The proposed desalination plant in Barangay Nalus, Kiamba, Sarangani Province, Philippines, has three main processing areas. These areas include the pre-treatment for particle removal, desalination of seawater, and post-treatment to comply with domestic water standards in the country. The economic assessment revealed a total capital expenditure of $2,364,317.00 with a unit product cost of $9.75/m3 or a selling price of $12.68/m3 with a 30% markup. The high capital and product costs are due to the low production rate, the novelty of the technology, expensive membrane cost, and extensive land area requirement. Profitability analysis for a selling price of $12.68/m3 revealed a more than 14-year payback period, a loss of $235,000.00, and a high 41% chance of being unprofitable. Reducing the product price to a market price of $1.17/m3 also reveals no profit at all: a loss of $4.6 million and a 100% chance of being unprofitable. Thus, it is highly recommended to delay construction of the proposed plant until the technology becomes matured and fully developed to produce a competitive price-wise membrane-based desalinated seawater.