Identifying greenhouse gas emission reduction potentials through large-scale photovoltaic-driven seawater desalination

Abstract

To widely promote freshwater production through seawater desalination, renewable energy is expected to replace traditional fossil energy to drive seawater desalination. Based on the input list of components and materials, this study attempts to quantify greenhouse gas (GHG) emissions of photovoltaic-driven seawater desalination projects through replacing traditional thermal power plants and evaluate GHG emission reduction potentials by comparing the thermal- and photovoltaic-driven seawater desalination projects. The GHG emission of photovoltaic-driven seawater desalination project could be reduced by 94.97 % compared with the thermal-driven seawater desalination project, and the GHG emission per unit water production is reduced by 9.8 kg CO2-eq/ton, which could greatly reduce GHG emissions in the whole life cycle. In addition, it is estimated that the large-scale implementation of photovoltaic power stations in LT-MED seawater desalination project can reduce GHG emissions from 1.61E+05 to 3.86E+06 t CO2-eq per year. Through the payback period assessment, the combination of photovoltaic power stations and thermal power plants to drive the seawater desalination project can offset the GHG emission of 7.94E+03 t CO2-eq, and the payback period of photovoltaic-driven seawater desalination project is estimated to be 0.33 years. Using renewable energy instead of traditional thermal energy can reduce the fossil fuel combustion and GHG emissions during the water desalination process, which provides essential references for the low-carbon transition and energy saving in seawater desalination projects in China's coastal areas.