WELCOME to the Bay of Fundy in eastern Canada, home to the highest tides in the world. Here, 100 billion tonnes of Atlantic seawater flow in and out of the 270-kilometre-long bay every day. The sea level at Fundy rises by an average of 11 metres, reaching a maximum of 17 metres at the narrowest point, twice a day without fail, thanks to the moon’s gravitational pull. Could this tidal movement be used to generate power?
The unwavering predictability and scale of the tides in some parts of the world make them an attractive renewable energy source. The World Energy Council estimates that Fundy’s tides alone could generate 17,000 gigawatt-hours (GWh) of energy per year. Some estimates put the energy in the world’s tides at as much as 1 million GWh per year, or about 5 per cent of the electricity generated worldwide, though only a fraction of this is likely to be exploited due to practical constraints.
The tides may contain as much as 5 per cent of the world’s energy
With so much to gain, it is little wonder that in recent years interest in tidal power has risen and investment has flowed in. Yet it is an enterprise fraught with engineering and environmental challenges. In addition, tidal energy is unevenly distributed across regions and countries, with local geography determining whether it will be economically viable in any given area. Still, there are plenty of researchers, small companies and would-be entrepreneurs vying to harvest the ocean’s bounty of “blue energy”.
One method for harvesting tidal energy is the use of barrages – dams …