New technology with great potential
Tides are a predictable, consistent and inexhaustible source of energy. The potential energy of the water can be converted into electricity with great efficiency. With its 80% it is much higher than the other energy sources. Triggered by low tide and high tide, currents have already been used in the past in locations with a large tidal range.
Examples are the tidal power station Rance in France, which has been supplying power for north France since 1967, and the Sihwa-ho station in Korea, which is the largest of its kind with an output of 254 MW. These stationary power stations are characterized by large inlet structures.
However, the new technology relies on a compact and partially modular design and/or mobile and visually unobtrusive systems which are universally deployable yet do not greatly impact the marine habitat with its flora and fauna. Among other things, it is implemented by using new types of current turbines that are comparable to a wind turbine under water. They can also produce power during slow currents and a low tidal range. The generated power is conducted over cable to the mainland.
The potential of energy to be produced largely depends on the location. The faster the tides flow, the higher the yield, and it may not be too far away from the consumers. Preferred locations are found, among others, in Nova Scotia Canada, Southeast Asia, North Australia and around the British Isles. According to a study, approx. 20% of Great Britain's requirements could be covered with energy from marine current power stations.
Applied systems and trial
Well-known international companies have implemented innovative concepts, machines and installations in recent years. New technical concepts, installations and turbines were and are being tried and tested, among others, in the waters off the shores of the Scottish Orkney Islands. The EMEC (European Marine Energy Centre) provides the required infrastructure for installation and operation as well as measurement data evaluation and analysis to the companies there.
In the technically well-engineered area of current turbines, three categories of systems have proven to be feasible:
- Individual turbines lowered to the seabed
- Platforms with several individual turbines
- Turbines anchored to the seabed and floating in the current (e.g. Kites).
For the current turbines installed in these applications, EagleBurgmann was able to provide the customers with robust and reliable sealing technology already during the development phase. But different types of EagleBurgmann mechanical seals were also delivered to the other (pilot) projects of e.g. GE (Alstom, RollsRoyce) and SEW Eurodrive.