To reduce global carbon emissions and meet The Paris Agreement targets, countries will need to make significant investments in renewable energy. Proven renewable energy sources like wind and solar rightfully grab the headlines, but other renewables, such as ocean energy, also hold promise.
Ocean energy sources, such as wave energy and tidal energy, harness the motion of the sea to produce power. The Department of Energy estimates that energy from waves, tides, and ocean currents have the combined potential to power millions of homes.
Tidal energy, in particular, is a relatively underdeveloped power source that could play an impactful role in the expansion of renewable energy generation in the future.
What is tidal energy and how does it work?
Tidal energy is generated using the rising and falling of the tides.
The most common way to produce tidal energy is through tidal streams. First, a turbine is placed in a fast-flowing body of water created by tides. Then, just as a wind turbine captures energy from the flow of air, the turbine generates energy from the flow of the water. A diagram of different tidal stream structures is shown below.
Another approach to tidal power generation uses a barrage, which is a large dam constructed across tidal bays, rivers, and estuaries. Barrages use turbines contained within the dam to generate power as the tide rises and falls. The barrage gates open as the tide rises and, at high tide, the gates close, creating a pool. Water is then released through the barrage’s turbines to generate energy at a controllable rate.
Tidal lagoons can also generate power. These bodies of ocean water are partially enclosed by a natural or manmade barrier and function like barrages, with turbines moving as the lagoon fills and empties with the tides.
The limitations of tidal energy
The expansion of tidal energy operations is limited by logistical challenges and environmental concerns. Of the few commercial tidal power plants in operation, the Sihwa Lake Tidal Power Station in South Korea is the largest. This single power station produces enough energy to support the domestic needs of a city with 500,000 people. It, however, is a rare success story.
“Investors are not enthusiastic about tidal energy because there is not a strong guarantee that it will make money or benefit consumers,” wrote National Geographic. “Engineers are working to improve the technology of tidal energy generators to increase the amount of energy they produce, to decrease their impact on the environment, and to find a way to earn a profit for energy companies.”
Tidal stream installations, for instance, disrupt the very tides that they are trying to harness, which can have a negative environmental impact. Barrages can change the salinity of the surrounding water, impacting the organisms that live there.
Tidal energy plants are also expensive to construct. Barrages, for example, are major construction projects and, once complete, require constant supervision to manage and adjust power output.
How can ocean data help optimize tidal energy operations?
Overcoming the operational challenges of tidal energy generation starts with access to better ocean data. Sofar Ocean’s Spotter buoys, which collect and transmit wave, wind, sea surface temperature, and barometric pressure data in real-time, can be rapidly deployed on a mooring or as a drifter to collect site-specific data in support of tidal energy site development and operations. Spotters are already actively used by multiple companies in the ocean energy space, including Eco Wave Power and Wave Swell Energy.
Interested in learning more about how ocean data can help support tidal energy operations? Schedule a demo with our team.
To access additional posts, visit our blog.