Applicability of pressure retarded osmosis power generation technology in Sri Lanka

Abstract

In this study the applicability of pressure retarded osmosis power generation was investigated in order to fulfil current electricity demand in Sir Lanka. Pressure retarded osmosis (PRO) process is a renewable and green technology with zero carbon emission to the environment. Salinity gradient through a membrane is the key parameter in osmotic pressure development. Theoretically it is a pressure increment of 26 bar which is equivalent to 270 m high water column for fixed volume of salt water compartment. This hydrostatic pressure can be used to generate electricity by sending pressurized water through a turbine. According to the literature, 1 MW electricity generation requires 1m3/s flow of fresh water.

Sri Lanka has a great potential to develop this technology as it is surrounded by sea. Subsequently the country is having 103 number of water rich river basins over the country. Currently the electricity demand of the entire country is about 2100MW and it is already being supplied by both hydro and thermal power plant. The country spends an immense amount of money for the thermal power generation in every year. This can be reduced by introducing PRO power generation. Calculations over the PRO power generation reveal that it is possible to generate 7.84% of country energy requirement via some selected river basins through this technology.