The largest obstacle that tidal energy must overcome is it’s lack of use. The technology to develop systems that convert tidal energy into useable forms of energy area available, however they can be time consuming projects that require large scale construction processes. This has deterred further investments in tidal energy as a whole.
Another large scale problem is that the current cost of tidal energy is much higher than that of fossil fuels. In 2011 it was measured that coal production costs were around 3.23 cents per kilowatt hour. This cost is much lower than the cost of tidal energy which averages between 8-12 cents per kilowatt hour in 2006. However, it is projected that this cost could be lowered down to between 4-6 cents per kilowatt hour in the future.10 If tidal energy can be lowered to this amount, it could see a growth in usage.
The other main obstacle is the effect that these systems could have on the aquatic ecosystem. The introduction of a large power generator could disrupt the day to day activities of aquatic life in the area. Individuals are currently developing generators that contain built in sonar systems that would monitor the movements of animals in the area of the tidal energy generator.
Along with this, a large problem with tidal barrages is the transportation of sewage and waste out to larger bodies of water. With the tide of the water being somewhat altered towards the tidal barrage, unnecessary waste could move from a location near a shore to open water. This being said, designs that allow for the flow of the tides to run naturally through barrages are being developed.