Abstract
As the demand of freshwater continuous to rise, the water desalination can act as prominent solution to address the global water scarcity. However, significant environmental concerns arise as the process is mainly powered by fossil fuel, which contributes to greenhouse gas emissions and thus leading to global warming. This research intends to explore the potential of renewable energy sources to effectively reduce freshwater production cost. Specifically, it intends to estimate the power generated and freshwater production cost of a multi-effect distillation (MED) desalination process, powered by solar and wind energy sources in addition to a comparison against the performance of an MED process powered by fossil fuel based conventional steam boiler. The comparison of energy efficiency and freshwater production cost is conducted in two different UK locations: Wick in the north of Scotland and Watchet in the south of England. MED process model with both wind power and solar energy models are developed to estimate the freshwater production cost while assuring 12kg/s of freshwater for small coastal communities. The results ascertain that both energy sources are able to produce thermal energy required for the MED process. Statistically, for a full day, 4029 kWh and 16383 kWh amounts of electricity can be generated in Watchet and Wick, respectively. Referring to wind powered MED, the freshwater production cost in Watchet is estimated at $20.49 per m³ of freshwater whereas it is reduced to $5.56/m³ at Wick as due to stronger and more consistent wind speeds, which is less than a third of the Watchet freshwater production cost. However, solar powered MED shows a much smaller difference between the locations: $1.87/m³ in Watchet and $3.11/m³ in Wick. Based on the results of freshwater production cost, the solar energy for MED process is more efficient in Watchet, whereas wind energy for MED process is more efficient in Wick.