The coming and going of the tide gives a form of renewable energy of distinct advantage over other sources that are not as predictable and reliable, such as wind or solar. Almost 10% of the United Kingdom’s electricity needs is met by tidal power.

Tidal barrage is where a dam or barrage is built across an estuary or bay that experiences an adequate tidal range. This tidal range has to be in excess of 5 metres for the barrage to be feasible. The purpose of this dam or barrage is to let water flow through it into the basin as the tide comes in. The barrage has gates in it that allow the water to pass through. The gates are closed when the tide has stopped coming in, trapping the water within the basin or estuary and creating a hydrostatic head. As the tide recedes outwith the barrage, gates in the barrage that contain turbines are opened, the hydrostatic head causes the water to come through these gates, driving the turbines and generating power. Power can be generated in both directions through the barrage but this can affect efficiency and the economics of the project.

This technology is similar to Hydropower, something that we have a lot of experience with in Scotland. There is potential for a project of this kind in Nigeria. The construction of a barrage requires a very long civil engineering project. The barrage will have environmental and ecological impacts not only during construction but will change the area affected forever. Just what these impacts will be is very hard to measure as they are site specific, and each barrage is different.

Tidal Streams are common in remote areas. This means that careful consideration of the wishes of the local community is required to ensure the scheme can work to its potential. Being under water avoids aesthetic problems and shipping and navigation should not be affected provided it is taken into consideration when planning. The scheme can provide employment during construction and operation, which will add to the local economic prosperity. Also, these schemes are unique at present and would help to put the area on the map.


Being experts in research of renewable energy, Harri-tonas has developed technology to utilize the various rivers and streams across the country to generate electrical power for te local communitee residence and businesses.