The history of tidal energy 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. Perhaps a scale large enough to power entire communities or countries.
Given the problems our world is facing, tidal energy is a renewable energy source that could completely change how we produce our energy needs. 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 toward our green targets as the right ingredients are in place to tap this renewable energy source further2.
Despite the potential challenges, tidal energy is not a new technology3. Similarly, it is not a new energy source because tidal energy has a long history.
How Did We Come to Understand Tidal Energy?
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. We can safely assume that we have been using tidal energy long before this time.
Our predecessors created tidal power plants using 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, they impounded the water before releasing it through a waterwheel.
Of course, this didn't generate electricity which we now associate with tidal energy. Instead, they used these early applications of tidal energy for grinding grain. They provided as much as three hours' worth of power each day. These became known as tide mills6.
The Concept Moved Across to America
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 produce 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 electricity demand, 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 and 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, Nova Scotia Light and Power of Halifax commissioned another set of studies. 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 1960s Came Progress
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 from the difference in tidal range between low and high tides. La Rance hence began the more modern history of tidal energy5.
Following this, in 1982, the second commercial-scale tidal barrage was installed 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.
Present Day Tidal Energy
Currently, the world's largest tidal power plant 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 an environmental meltdown, tidal energy faces its own challenges.
Tidal energy cost remains one of the main challenges throughout the lifetime of an installation. Barrages and tidal lagoons can prove costly to construct while they can only use the maximum power at a particular time. However, one of the main concerns is the environmental impact. The local ecosystem can face disruption, and it can affect marine life.
On the upside, tidal energy doesn't result in huge amounts of flooded land like hydropower, it's water-powered relation.
Maintenance is a challenge while some of the best tidal currents are out of reach. Many occupy shipping channels, while the geographical location puts them too far from the grid.
The Future of Tidal Energy
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 entirely where it needs to be.
All the same, with a growing requirement for cleaner energy, tidal energy may well prove an essential 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.
As we ramp up efforts to net-zero and cleaner energy sources, we can expect more tidal energy devices and tidal power projects to generate power.
|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.19126.96.36.199
|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