Seventy per cent of the globe is covered by water. That adds up to an ocean of possibilities for marine energy technology developers wanting to create clean, renewable energy. Scotland’s Orkney Islands are considered the epicentre of today’s ocean energy research and development. Top players in both wave and tidal power are situated here, taking advantage of the ideal conditions the north Atlantic offers. The industry is still at the embryonic phase with only prototypes at work in the waters, but SKF is there providing knowledge from its experience in both the wind and the oil-and-gas industry. Knowledge engineer Cengiz Shevket and his ocean energy team visit the Orkney Islands for the first time to see first hand how SKF can further help the industry overcome today and tomorrow’s challenges. Reliability, maintainability and availability are key to survival in the harsh environment that is the ocean

Ocean energy

For long term viability of the ocean energy sector, reducing the cost of energy (COE) to a level competitive with offshore wind and other traditional power generation methods is absolutely key.

Overcome ocean energy challenges with SKF

SKF has many decades of experience working within the wind, marine, hydro-electric and offshore oil and gas industries around the world. SKF is now using the technical knowledge and innovative skill gained from these synergistic industries to address ocean energy challenges. Based in Scotland, our Ocean Energy team works collaboratively with prototype device developers and sub-component suppliers, helping them design in reliability at an early stage. Our efforts help to ensure they meet their future availability and production targets. We also help optimize maintenance strategy and take maintainability issues into consideration, recognising the harsh and inaccessible environments in which ocean energy equipment must operate.

SKF solutions to convert wave motion to electricity

Special buoys, turbines, and other technologies convert the natural movement of ocean waves into clean, renewable electricity. Regardless of the technology, SKF’s knowledge can play a key role in system behaviour, with expertise in pumps, hydroelectric turbines, hydraulic cylinders, linear motion technologies and generators. In addition to the solutions listed below, we have the expertise and knowledge to customise existing solutions to create new innovative offers addressing specific technical challenges in the wave sector.

The MeyGen project in Pentland Firth, Scotland, is the world’s largest tidal-stream project to date. It will have a huge significance for the future of sustainable energy supply.

With climate change being a pressing global threat to the world’s economy and environment, there is a strong need to deliver clean, renewable and sustainable energy. Tidal energy is one step towards a transition to a low-carbon economy and an increased renewable energy share for households and communities around the world.

Tidal energy is classified as an ocean technology that converts the energy caused by cyclical movements of the sea into electricity. There are three ways to generate electric energy from the tides; one of these is via underwater propellers (similar to windmills) powered by tidal streams.

The world’s largest planned tidal-stream project to date is the MeyGen project in Scotland’s inhospitable Pentland Firth. Here, ANDRITZ HYDRO Hammerfest, based in Glasgow (UK) and part of ANDRITZ HYDRO in Austria, is supplying three of the four turbines for the initial phase 1a. The project is considered to have the utmost significance for power gener-ation and potentially for the future of sustainable energy supply. The turbines have a capacity of 1.5 megawatts each, and a rotational speed of 14 revolutions per minute. The plan is to have 270 turbines operating in 2020, at a full capacity of 398 MW.

This requires careful engineering, manufacturing and assembly, ensuring the reliable operation and high performance of the deployed technology. Dr Carsten Hermann, of the Design and Development Department of Andritz Hydro in Ravensburg, Germany

The tidal turbines will be placed in the Inner Sound of the Pentland Firth, in the waters that separate the northern Scottish mainland from Stroma Island. It is home to whales and dolphins and other marine animals and is well known for its tidal streams, which are among the fastest in the world, with speeds of up to 18 kilo-metres per hour. With a suitable water depth of about 30 metres and very high flow velocity of up to five metres per second, it is potentially one of the best spots worldwide for tidal power generation. ANDRITZ HYDRO plant in Ravensburg, Germany

Assembly of two tidal turbine nacelles at the ANDRITZ HYDRO plant in Ravensburg, Germany.

Nevertheless, the neighbouring Atlantic Ocean with its rough conditions makes the Inner Sound of the Pentland Firth one of the most challenging maritime environments on earth. As such, it is a complex location for operation that requires state-of-the-art machinery. “This requires careful engineering, manufacturing and assembly, ensuring the reliable operation and high performance of the deployed technology,” says Dr Carsten Hermann, of the Design and Development Department of ANDRITZ HYDRO in Ravensburg, Germany, where the turbines are manufactured. The components developed and delivered by ANDRITZ HYDRO have a predicted service life of about 25 years with a maintenance interval of five years.

Advances in tidal stream technology enable the production of a high degree of energy output. Few companies are developing expertise in this market, but ANDRITZ HYDRO has many years of experience in ocean technology. The company delivered and installed the entire electro-mechanical equipment for the world’s largest tidal power plant (254 MW) in Sihwa, South Korea. Most recently the company received an order for the rehabilitation of the tidal power plant in La Rance, France.

The design of the tidal turbines that are currently in production for the Penthland Firth is based upon the former prototypes that were tested in Kvalsund, Norway, installed in 2003 (300 kW) and at the European Marine Energy Centre, Orkney Islands, installed in 2011 (1,000 kW). In 2014, this development and know-how resulted in an order for the world’s first commercial tidal current power plant in Pentland Firth, Scotland.




A comprehensive offering

SKF has assisted ANDRITZ HYDRO with technical expertise, in particular in the design of the propeller shaft bearing arrangement, life calculations, both dynamic and static (safety) calculations, and the specific execution of the customized bearings. SKF also assisted with specific tools and specified mounting procedures for the propeller shaft bearings and a special front seal by SKF Marine.

For more information or assistance please contact us.

Written by


SKF logo