Original sentence: Another form of tidal barrage configuration is that of the dual basin type.As a result, a tidal power scheme may not produce returns for many years, and investors may be reluctant to participate in such projects.Barrage systems are sometimes affected by problems of high civil infrastructure costs associated with what is in effect a dam being placed across estuarine systems, and the environmental problems associated with changing a large ecosystem.Even with the most fish-friendly turbine design, fish mortality per pass is approximately 15%  (from pressure drop, contact with blades, cavitation, etc.Many governments have been reluctant in recent times to grant approval for tidal barrages.The head is used to drive turbines.The placement of a barrage into an estuary has a considerable effect on the water inside the basin and on the ecosystem.Tidal energy has an efficiency of 80% in converting the potential energy of the water into electricity , which is efficient compared to other energy resources such as solar power or fossil fuel power plants
Edited sentence: Another form of tidal barrage energy is that of the dual basin type.As a result, a tidal power scheme may not produce returns for many years.Barrage systems are affected by problems of high civil infrastructure costs associated with what is in effect a dam being placed across estuarine systems, and the environmental problems associated with flodding a large ecosystem.Even with the most fish-friendly turbine design, fish mortality per pass is approximately 15% (citation needed) (from pressure drop, contact with blades, cavitation, etc.Investors are thus reluctant to participate in such projects.Many gorernments and ecologists have been reluctant in recent times to grant approval for tidal barrages.The head (height of water behind the barrage wall) is used to drive turbines.The placement of a barrage into an estuary has a considerable effect on the water inside the basin and on the ecosystem that is being flooded.Tidal energy has an efficiency of 80% (citation needed)in converting the potential energy of the water into electricity, which is efficient compared to other energy resources such as solar power or fossil fuel power plants