Orkney, also known as the Orkney Islands, is an archipelago in the Northern Isles of Scotland, situated off the north coast of the island of Great Britain. Orkney is 10 miles (16 km) north of the coast of Caithness and has about 70 islands, of which 20 are inhabited. The largest island, the Mainland, has an area of 523 square kilometres (202 sq mi), making it the sixth-largest Scottish island and the tenth-largest island in the British Isles. Orkney's largest settlement, and also its administrative centre, is Kirkwall.
The Pentland Firth is a strait which separates the Orkney Islands from Caithness in the north of Scotland. Despite the name, it is not a firth.
Tidal power or tidal energy is harnessed by converting energy from tides into useful forms of power, mainly electricity using various methods.
Eday is one of the islands of Orkney, which are located to the north of the Scottish mainland. One of the North Isles, Eday is about 24 kilometres from the Orkney Mainland. With an area of 27 km2 (10 sq mi), it is the ninth-largest island of the archipelago. The bedrock of the island is Old Red Sandstone, which is exposed along the sea-cliffs.
The Northern Isles are a chain of islands off the north coast of mainland Scotland. The climate is cool and temperate and highly influenced by the surrounding seas. There are two main island groups: Shetland and Orkney. There are a total of 36 inhabited islands, with the fertile agricultural islands of Orkney contrasting with the more rugged Shetland islands to the north, where the economy is more dependent on fishing and the oil wealth of the surrounding seas. Both archipelagos have a developing renewable energy industry. They share a common Pictish and Norse history, and were part of the Kingdom of Norway before being absorbed into the Kingdom of Scotland in the 15th century. The islands played a significant naval role during the world wars of the 20th century.
The Pelamis Wave Energy Converter was a technology that used the motion of ocean surface waves to create electricity. The machine was made up of connected sections which flex and bend as waves pass; it is this motion which is used to generate electricity.
The production of renewable energy in Scotland is a topic that came to the fore in technical, economic, and political terms during the opening years of the 21st century. The natural resource base for renewable energy is high by European, and even global standards, with the most important potential sources being wind, wave, and tide. Renewables generate almost all of Scotland's electricity, mostly from the country's wind power.
Helliar Holm is an uninhabited island off the coast of Shapinsay in the Orkney Islands, Scotland. It is home to a 42-foot-tall (13 m) lighthouse, which was built in 1893 and automated in 1967. It is a tidal island that used to be connected to Shapinsay. It is still possible to walk across from the mainland during very low tides.
Thieves Holm is a small island in Orkney, Scotland.
The European Marine Energy Centre (EMEC) Ltd is a UKAS accredited test and research center focused on wave and tidal power development, based in the Orkney Islands, UK. The centre provides developers with the opportunity to test full-scale grid-connected prototype devices in wave and tidal conditions.
The Oyster was a hydro-electric wave energy device that used the motion of ocean waves to generate electricity. It was made up of a Power Connector Frame (PCF), which is bolted to the seabed, and a Power Capture Unit (PCU). The PCU is a hinged buoyant flap that moves back and forth with movement of the waves. The movement of the flap drives two hydraulic pistons that feed high-pressured water to an onshore hydro-electric turbine, which drives a generator to make electricity. Oyster was stationed at the European Marine Energy Centre (EMEC) at its Billia Croo site in Orkney, Scotland until the company ceased trading in 2015.
Aquamarine Power was a wave energy company, founded in 2005 to commercialise the Oyster wave energy converter, a device to capture energy from near-shore waves. The company's head offices were in Edinburgh, Scotland. The company ceased to trade on 20 November 2015.
A tidal stream generator, often referred to as a tidal energy converter (TEC), is a machine that extracts energy from moving masses of water, in particular tides, although the term is often used in reference to machines designed to extract energy from the run of a river or tidal estuarine sites. Certain types of these machines function very much like underwater wind turbines and are thus often referred to as tidal turbines. They were first conceived in the 1970s during the oil crisis.
St Magnus Bay is a large coastal feature in the north-west of Mainland Shetland, Scotland. Roughly circular in shape with a diameter of about 19 kilometres (12 mi), it is open to the North Atlantic Ocean to the west. The indented coastline to the north, south and east between Esha Ness in the north and the Ness of Melby in the south contains numerous bays, firths and voes and there are several islands around the perimeter. The waters of the bay are up to 165 metres (541 ft) deep and may have been the site of a substantial meteor impact.
Orbital Marine Power is a Scottish renewable energy company focused on the development and global deployment of its pioneering floating turbine technology. The O2 is Orbital's first commercial turbine and represents the culmination of more than 15 years of world leading product development in the UK. The 74 m long turbine is expected to operate in the waters off Orkney for the next 15–20 years with the capacity to meet the annual electricity demand of around 2,000 UK homes with clean, predictable power from the fast-flowing waters while offsetting approximately 2,200 tonnes of CO2 production per year. In a further ground-breaking element of the project, the O2 will provide power to the European Marine Energy Centre's onshore electrolyser to generate green hydrogen that will be used to demonstrate decarbonisation of wider energy requirements.
Many tidal stream generators have been developed over the years to harness the power of tidal currents flowing around coastlines. These are also called tidal stream turbines (TST), tidal energy converters (TEC), or marine hydro-kinetic (MHK) generation. These turbines operate on a similar principle to wind turbines, but are designed to work in a fluid approximately 800 times more dense than air which is moving at a slower velocity. Note that tidal barrages or lagoons operate on a different principle, generating power by impounding the rising and falling tide.
OpenHydro Group Ltd was an Irish developer of tidal stream turbines, established in 2004. It was acquired by Naval Energies in 2013, however, Naval Energies decided in July 2018 to stop developing tidal turbines and focus on floating wind turbines. The company subsequently went into liquidation with debts of about €280m.
