Salinity Gradient Energy Potential of Mozambique Estuaries

Abstract

Sub-Saharan Africa, and in particular Mozambique, has considerable potential of salinity gradient energy, which could foster coastal development. However, the lack of scientific based information hinders the development of policies and investments in harnessing this source of energy in Sub-Saharan Africa. The present study, used historical data of temperature and salinity and estimated the potential of salinity gradient power in four main estuaries in Mozambique. The theoretical salinity gradient power ranged, on average, from 843.6 MW, in Incomati River estuary to 2,800.0 MW in Zambezi Delta. The Bons Sinais Estuary and Limpopo Estuary had 1,086.8 MW and 1292.0 MW, on average, respectively. The salinity power estimated in the Mozambique estuaries studied was above the maximum power densities for electrodialysis osmotic energy storage systems, which is set at 5 W m⁻², and has potential extractable energy of about 3,000MW, and could benefit about 2 million coastal rural households (about 7% of the total Mozambican population) on irrigation and lighting houses. Further studies may be focused in determining the seasonal and salinity intrusion effects on salinity power gradient in the Mozambican estuaries.

Keywords:

• Salinity gradient energy
• pressure-retarded osmosis
• electricity
• desalination

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The research was part of PhD studies on renewable energy, financially supported by the Eduardo Mondlane University post-graduate research grant, under SIDA-SAREC Project No 2.1.6.