Europe has been studying tidal and wave power since the 1960s. Since then, there have been several implementations of tidal and wave power. With other forms of low-carbon power sources being developed and already in use, there are still a lot of hurdles to overcome before wave and tidal power become mainstream sources of energy. So far, there are studies and bold plans for tidal power plants and wave power plants in the United Kingdom, Alaska and Australia.
‘The oldest tidal power plant is in the Rance River in France which generates 240MW’
Around the world there have been tidal and wave power plants since the 1960s. The oldest tidal power plant is in the Rance River in France which generates 240MW. Apart from being the oldest power plant of its kind, it is also the second biggest in terms of power generation. The biggest tidal power plant is located in the Sihwa Lake in South Korea. It generates 254MW and uses a seawall which was built in 1994 for flood control and agricultural purposes.
Compared to wind and solar, tidal and wave power lags behind. Primary reason for this is the technological hurdles. Another reason is the larger investment. In addition, there are fewer locations where a tidal or wave power plant can be located.
‘The biggest tidal power plant is in the Sihwa Lake in South Korea and generates 254MW’
In Alaska, for instance, Yakutat has waves which measure 20 feet high. The potential power generation output from the waves could easily power Yakutat, which is home to 600 people. The town currently depends on its own diesel engine generator for its power requirements. In terms of technology and logistics, wave power is the only option for the small town. Prior research and studies has shown that the town would need around 30 wave energy converters, each costing a million dollars, to power the whole town, Alaska Public reported.
Whether using tidal or wave power is expensive due to its being a new technology. Almost every implementation has used a different approach. There has not been enough installations and power plants to leverage the technology and spread the cost.
There is however, a discrepancy between estimates about how much it would really cost to harness tidal or wave energy. A 2015, the Department of Energy had a “baseline estimate for floating, deep-water energy” of $0.90 per kilowatt hour (kWh). By 2017, the figure has gone down to $0.66/kWh. They have a goal to make this $0.17/kWh by 2030.
Part of the expense is due to the need for protection against the weather and saltwater corrosion. One solution for this is to use equipment which are totally submerged. This approach has been used in Australia, where the movement of the waves is harnessed with the use of a tethered buoy which is connected to a pump. Water is pumped to the mainland, where it runs turbines.
Most of the new designs make use of buoys, instead of submerged propellers or turbines. This allows a lower cost of equipment, installation, as well as maintenance. This bold approach can also be scalable by just multiplying the number of buoys.
The potential for wave and tidal power is huge and could generate a big chunk of the world’s energy needs. It is another untapped resource that has yet to be fully understood and harnessed. But once it is, it is a bold and commercially-viable, not to mention, more eco-friendly source of power that would make a huge impact on the planet.