A Techno-Economic Analysis of the Potential for Salinity Gradient Power Generation in the Gambia
Open Access
- Author:
- Hughes, David Richard
- Area of Honors:
- Elective Area of Honors - Engineering Leadership Development
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Andrew Zydney, Thesis Supervisor
Andrew Michael Erdman, Thesis Honors Advisor - Keywords:
- Salinity Gradient Energy
Pressure Retarded Osmosis
Gambia
Electricity Generation - Abstract:
- As fresh river water flows into the sea, chemical potential energy is dissipated during the mixing process due to the large difference in salt concentration between these waters. It is possible to extract some of this chemical potential energy as useful work, offering the possibility of a reliable, local, renewable source of energy. The Gambia is a developing country on the coast of West Africa that is centered geographically, culturally, and historically on the Gambia River. Salinity gradient power using flow from the Gambia River could provide an attractive option as the Gambia looks to expand electricity generation capacity. A high-level technological and economic analysis of the production of electrical power using pressure retarded osmosis (PRO) was conducted to understand the short-term and long-term viability of this process for energy generation in the Gambia. Current membrane technology was modeled and a sensitivity analysis was carried out on key variables to determine the effects of possible future technological improvements. The short-term viability of this technology, both in the Gambia and in other regions around the world, is limited mainly by the current market landscape and the economics of the PRO process based on current membrane technology and prices. Membrane cost, membrane life, and water permeability are the key drivers that make the current technology more expensive than alternative energy sources. The long-term viability of PRO technology in the Gambia would also be limited by access to water with a sufficiently low salt concentration as saline water intrusion is significant in the Gambia River estuary. At this point, the capital investment for a PRO plant would likely be better spent investigating alternative energy generation technologies to provide reliable access to electricity for the Gambian people, but improvements in membrane cost and performance or changes in market conditions could make PRO an attractive option at some point in the future.