Tidal energy may not command the spotlight like solar or wind power, but it has quietly been harnessing the power of the ocean for decades. Driven by the Moon’s gravitational pull, tidal energy offers predictability unmatched by other renewables. As the world races toward a clean energy future, this ancient power source is re-emerging with cutting-edge technology and promising potential.
Tidal energy stands apart as a celestial gift, derived from the gravitational dance between the Earth and its Moon. This unique relationship is not only responsible for ocean tides but also for subtly reshaping our planet. Remarkably, the Moon drifts farther from Earth by approximately 3.8 centimetres each year. This dynamic gives tidal energy a cosmic significance, making it a renewable resource shaped by forces that transcend time.
Though modern tidal energy may seem futuristic, its roots stretch back to Roman times. Early tide mills harnessed the ebb and flow of water to grind grain, a testament to human ingenuity. Today’s systems, such as the La Rance Tidal Power Station in France, have advanced dramatically but remain built on the same core principle. These facilities convert the rise and fall of tides into reliable energy. However, despite its rich history, tidal energy remains a small yet potent contributor to the global energy landscape.
The suitability of tidal energy hinges on geography. While oceans envelop much of our planet, only specific locations boast the tidal ranges needed for efficient power generation. Sites like France’s La Rance and South Korea’s Sihwa Lake exemplify successful tidal range projects, where water is trapped and released through turbines to generate electricity. Exceptional locations, like Canada’s Bay of Fundy with its record-breaking tidal range of over 15 metres, highlight the immense potential of this energy source.
Environmental considerations also play a significant role in the evolution of tidal energy. Traditional barrage systems, which rely on dams, can disrupt marine ecosystems. This challenge has given rise to innovations like Scotland’s MeyGen project, which employs tidal stream technology. By utilising underwater turbines powered by swift tidal currents, MeyGen minimises ecological disruption while capturing renewable energy. Careful site selection ensures marine life can coexist with this innovative approach, offering a model for sustainable development.
Despite its promise, the high cost of tidal energy infrastructure remains a challenge. Facilities like South Korea’s Sihwa Lake Tidal Power Station and France’s La Rance demanded significant investments, with construction costs nearing hundreds of millions. While tidal systems achieve impressive energy conversion rates of up to 80%, their intermittent nature adds to scalability hurdles. Power is generated during tidal flows, resulting in predictable yet periodic energy production.
Nevertheless, tidal energy’s future glows with potential. Unlike wind and solar, tides can be forecast with precision years in advance, providing a stable and dependable energy source. Estimates suggest tidal power could produce 1,200 terawatt-hours of electricity annually, representing a substantial addition to the global renewable energy mix. As innovation drives costs down and ecological impacts are mitigated, tidal energy is poised to become a cornerstone of sustainable power.
Tidal energy embodies the intersection of ancient ingenuity and modern technology. Harnessing the natural movements of our oceans, this renewable resource promises to reshape the energy landscape while offering a dependable, environmentally conscious alternative.
SAE Renewables Limited (LON:SAE) was founded in 2005 as a supplier of tidal stream turbines, SAE quickly grew to include development of tidal stream projects and is the majority owner of MeyGen, the world’s largest tidal stream energy project.
