The history of tidal energy is one that goes further back in time than many of us might realize. The truth is, we have long understood the power of flowing water. Despite this, we still need to work out how to harness this power on a vast scale. A scale perhaps, that is large enough to power entire communities or countries.
Given the problems our world is facing, tidal energy is a source of renewable energy that could completely change the way in which we live. The UK, as an example, is an island. Surrounded by the ocean and fast-flowing tidal currents, the potential is undoubtedly there. However, whether it is funding, meeting demand, or the infrastructure, tidal energy could be a significant driver towards our green targets as the right ingredients are in place to further tap this renewable energy source2.
Despite the potential challenges, tidal energy is not a new technology3. Similarly, it is not a new source of energy because tidal energy has a long history.
The reality is that tidal energy is nothing new. In fact, the history of tidal energy dates back to our earliest understanding of when it was first in 900 A.D. As such, we can safely assume that we have been using tidal energy long before this time.
Our predecessors created tidal power plants that made use of naturally occurring tidal basins.
To harness its energy, they would build a barrage across the opening of the basin. This allowed one side of the basin to fill while the tide was rising. Once the tide dropped, the water was impounded before releasing it through a waterwheel. Of course, this didn’t generate electricity which we now associate with tidal energy. Instead, these early applications of tidal energy were used for grinding grain. They provided as much as three hours' worth of power each day. These became known as tide mills6.
In the 17th century, the settlers took the idea of a tide mill to America. It was first introduced in Maine and following this success examples of tide mills were shortly after found across the country. However, as the end of the 19th century arrived, the idea of using tidal power to generate electricity became a serious consideration4.
Then in 1921, A. M. A Struben wrote a book named Tidal Power. Here the book considered ways in which we could capture the energy from the tides. Dexter Cooper, an engineer, then came up with the idea of how we could create power from tides1. And so, this began the journey from using tidal energy to power water wheels to using tidal energy to create power. As such. we were moving on from tidal energy as we knew it in the middle ages. Now, a new era beckoned and with the growing demand for electricity, the future looked promising.
In 1924, the US Federal Power Commission carried out a study of large-scale tidal power plants. If the plants were built, as per the plans, their location would have been Maine as well as the Canadian province of New Brunswick. This would have included dams, ship locks, and powerhouses, all of which would have enclosed the Bay of Fundy and Passamaquoddy Bay8. Eventually, the study came to nothing and the funding would have been difficult following the depression.
Then, in 1956, another set of studies were commissioned by Nova Scotia Light and Power of Halifax. They looked at the idea of implementing a tidal power development on the Nova Scotia side of the Bay of Fundy. Once again, the cost was a problem despite acknowledging that the development would generate millions of horsepower.
With the arrival of the 1960s, we began to see more emphasis placed on tidal energy. As a result, this saw the commission of a report - “The Investigation of the International Passamaquoddy Tidal Power Project.” The findings indicated that the project was of benefit to the US but not to Canada.
Yet another study took place to reassess the potential of Fundy Tidal Power. As a result, it was found that three barrages at Chignetco Bay and Minas Basin were all feasible but again, they were not built. More proposals were put forward but cost-effectiveness was always a barrier.
The initial tidal barrages could not deal with the energy needs of an ever-changing world. However, in 1965 the French built the first commercial-scale, modern tidal power plant. Located in the Rance Estuary near St. Malo, France, new hydroelectric, efficient turbines were installed. A total of 24 turbo generators were in place and still, to this day, the plant is generating clean energy. La Rance hence began the more modern history of tidal energy5.
Following this, in 1982, the installation of the second commercial-scale tidal barrage took place in Nova Scotia. This was done to highlight the working of the STRAFLO Turbine, an invention by Escher-Wyss of Switzerland. Despite its initial problems, the plant now generates electricity with no issues.
Currently, the largest tidal energy power plant in the world is the Sihwa Lake Tidal Power Station7. Located in South Korea, it has a capacity of 254 MW. Amazingly, this is the only project that has surpassed the La Rance Tidal Power Plant. So, for 54 years, this plant perhaps suggests we have taken tidal energy as far as we can go for the time being.
Unlike other forms of renewable energy, there has been a clear lack of progress or adoption. Questions have to be asked about why the La Rance Tidal Power Plant, which has been in place since 1966 is still one of the biggest in the world?
Of course, while the world faces environmental meltdown, tidal energy faces challenges of its own.
Tidal energy cost remains one of the main challenges throughout the lifetime of an installation. Barrages can prove costly to construct while they can only make use of the maximum power at a certain time. However, one of the main concerns is the environmental impact. The local ecosystem can face disruption and it can affect marine life.
Along with this, maintenance is a challenge while some of the best tidal currents are out of reach. Many of them occupy shipping channels while the geographical location puts them too far from the grid.
So, progress is slow, the costs are high and the impact on ecology is higher. With all of these factors playing a part, perhaps tidal energy is not quite where it needs to be. All the same with a growing requirement for cleaner energy tidal energy may well prove an important part of the mix. With many great minds looking to provide more efficient ways to generate our future energy needs, the largely untapped potential of our tides remains a compelling opportunity.
|David A. Brooks, The tidal-stream energy resource in Passamaquoddy–Cobscook Bays: A fresh look at an old story, Renewable Energy, Volume 31, Issue 14, 2006, Pages 2284-2295, ISSN 0960-1481, https://doi.org/10.1016/j.renene.2005.10.013|
|Global Perspective: Economic Forecast for Renewable Ocean Energy Technologies. Jones, Anthony T. Rowley, Will. Marine Technology Society Journal, Volume 36, Number 4, Winter 2002, pp. 85-90(6) https://doi.org/10.4031/002533202787908608|
|Benoit Dal Ferro, Wave and tidal energy: Its Emergence and the Challenges it Faces, Refocus, Volume 7, Issue 3, 2006, Pages 46-48, ISSN 1471-0846, https://doi.org/10.1016/S1471-0846(06)70574-1|
|Mehmood, Nasir & Liang, Zhang & Khan, Jawad. (2012). Harnessing Ocean Energy by Tidal Current Technologies. Research Journal of Applied Sciences, Engineering and Technology. 4.|
|LEBARBIER, C.H. (1975), POWER FROM TIDES— THE RANCE TIDAL POWER STATION. Naval Engineers Journal, 87: 57-71. doi:10.1111/j.1559-3584.1975.tb03715.x|
|Stephen A. Royle (1982) Tide Mills: An Example from Brittany, Industrial Archaeology Review, 6:3, 241-244, DOI: 10.1179/iar.1918.104.22.168|
|Young Ho Bae, Kyeong Ok Kim, Byung Ho Choi, Lake Sihwa tidal power plant project, Ocean Engineering, Volume 37, Issues 5–6, 2010, Pages 454-463, ISSN 0029-8018, https://doi.org/10.1016/j.oceaneng.2010.01.015|
|Charlier R.H., Finkl C.W. (2008) Harnessing the Tides in America. In: Ocean Energy. Springer, Berlin, Heidelberg|