Marine energy

Marine energy or marine power (also sometimes referred to as ocean energy, ocean power, or marine and hydrokinetic energy) refers to the energy carried by ocean waves, tides, salinity, and ocean temperature differences. The movement of water in the world’s oceans creates a vast store of kinetic energy, or energy in motion. Some of this energy can be harnessed to generate electricity to power homes, transport and industries.

The term marine energy encompasses both wave power i.e. power from surface waves, and tidal power i.e. obtained from the kinetic energy of large bodies of moving water. Offshore wind power is not a form of marine energy, as wind power is derived from the wind, even if the wind turbines are placed over water.

The oceans have a tremendous amount of energy and are close to many if not most concentrated populations. Ocean energy has the potential of providing a substantial amount of new renewable energy around the world.[1]

Global potential

There is the potential to develop 20,000–80,000 terawatt-hours per year (TWh/y) of electricity generated by changes in ocean temperatures, salt content, movements of tides, currents, waves and swells[2]

Global potential
Form Annual
Tidal energy >300 TWh
Marine current power >800 TWh
Osmotic power Salinity gradient 2,000 TWh
Ocean thermal energy Thermal gradient 10,000 TWh
Wave energy 8,000–80,000 TWh
Source: IEA-OES, Annual Report 2007[3]

Indonesia as archipelagic country with three quarter of the area is ocean, has 49 GW recognized potential ocean energy and has 727 GW theoretical potential ocean energy.[4]

Forms of ocean energy


The oceans represent a vast and largely untapped source of energy in the form of surface waves, fluid flow, salinity gradients, and thermal.

Marine and Hydrokinetic (MHK) or marine energy development in U.S. and international waters includes projects using the following devices:

Marine current power

Strong ocean currents are generated from a combination of temperature, wind, salinity, bathymetry, and the rotation of the Earth. The Sun acts as the primary driving force, causing winds and temperature differences. Because there are only small fluctuations in current speed and stream location with no changes in direction, ocean currents may be suitable locations for deploying energy extraction devices such as turbines.

Ocean currents are instrumental in determining the climate in many regions around the world. While little is known about the effects of removing ocean current energy, the impacts of removing current energy on the farfield environment may be a significant environmental concern. The typical turbine issues with blade strike, entanglement of marine organisms, and acoustic effects still exists; however, these may be magnified due to the presence of more diverse populations of marine organisms using ocean currents for migration purposes. Locations can be further offshore and therefore require longer power cables that could affect the marine environment with electromagnetic output.[5]

Osmotic power

At the mouth of rivers where fresh water mixes with salt water, energy associated with the salinity gradient can be harnessed using pressure-retarded reverse osmosis process and associated conversion technologies. Another system is based on using freshwater upwelling through a turbine immersed in seawater, and one involving electrochemical reactions is also in development.

Significant research took place from 1975 to 1985 and gave various results regarding the economy of PRO and RED plants. It is important to note that small-scale investigations into salinity power production take place in other countries like Japan, Israel, and the United States. In Europe the research is concentrated in Norway and the Netherlands, in both places small pilots are tested. Salinity gradient energy is the energy available from the difference in salt concentration between freshwater with saltwater. This energy source is not easy to understand, as it is not directly occurring in nature in the form of heat, waterfalls, wind, waves, or radiation.[6]

Ocean thermal energy

Water typically varies in temperature from the surface warmed by direct sunlight to greater depths where sunlight cannot penetrate. This differential is greatest in tropical waters, making this technology most applicable in water locations. A fluid is often vaporized to drive a turbine that may generate electricity or produce desalinized water. Systems may be either open-cycle, closed-cycle, or hybrid.[7]

Tidal power

The energy from moving masses of water — a popular form of hydroelectric power generation. Tidal power generation comprises three main forms, namely: tidal stream power, tidal barrage power, and dynamic tidal power.

Wave power

Solar energy from the Sun creates temperature differentials that result in wind. The interaction between wind and the surface of water creates waves, which are larger when there is a greater distance for them to build up. Wave energy potential is greatest between 30° and 60° latitude in both hemispheres on the west coast because of the global direction of wind. When evaluating wave energy as a technology type, it is important to distinguish between the four most common approaches: point absorber buoys, surface attenuators, oscillating water columns, and overtopping devices.[8]

The wave energy sector is reaching a significant milestone in the development of the industry, with positive steps towards commercial viability being taken. The more advanced device developers are now progressing beyond single unit demonstration devices and are proceeding to array development and multi-megawatt projects.[9] The backing of major utility companies is now manifesting itself through partnerships within the development process, unlocking further investment and, in some cases, international co-operation.

At a simplified level, wave energy technology can be located near-shore and offshore. Wave energy converters can also be designed for operation in specific water depth conditions: deep water, intermediate water or shallow water. The fundamental device design will be dependent on the location of the device and the intended resource characteristics.


Petroleum and natural gas beneath the ocean floor are also sometimes considered a form of ocean energy. An ocean engineer directs all phases of discovering, extracting, and delivering offshore petroleum (via oil tankers and pipelines,) a complex and demanding task. Also centrally important is the development of new methods to protect marine wildlife and coastal regions against the undesirable side effects of offshore oil extraction.

Marine energy development

The UK is leading the way in wave and tidal (marine) power generation. The world's first marine energy test facility was established in 2003 to kick start the development of the marine energy industry in the UK. Based in Orkney, Scotland, the European Marine Energy Centre (EMEC) has supported the deployment of more wave and tidal energy devices than at any other single site in the world. The Centre was established with around £36 million of funding from the Scottish Government, Highlands and Islands Enterprise, the Carbon Trust, UK Government, Scottish Enterprise, the European Union and Orkney Islands Council, and is the only accredited wave and tidal test centre for marine renewable energy in the world, suitable for testing a number of full-scale devices simultaneously in some of the harshest weather conditions while producing electricity to the national grid.

Clients that have tested at the centre include Aquamarine Power, AW Energy, Pelamis Wave Power, Seatricity, ScottishPower Renewables and Wello on the wave site, and Alstom (formerly Tidal Generation Ltd), ANDRITZ HYDRO Hammerfest, Kawasaki Heavy Industries, Magallanes, Nautricity, Open Hydro, Scotrenewables Tidal Power, and Voith on the tidal site.

Leading the €11m FORESEA (Funding Ocean Renewable Energy through Strategic European Action) project, which provides funding support to ocean energy technology developers to access Europe's world-leading ocean energy test facilities, EMEC will welcome a number of wave and tidal clients to their pipeline for testing on site.

Beyond device testing, EMEC also provides a wide range of consultancy and research services, and is working closely with Marine Scotland to streamline the consenting process for marine energy developers. EMEC is at the forefront in the development of international standards for marine energy, and is forging alliances with other countries, exporting its knowledge around the world to stimulate the development of a global marine renewables industry.[10]

Environmental effects

Common environmental concerns associated with marine energy developments include:

  • the risk of marine mammals and fish being struck by tidal turbine blades[11]
  • the effects of EMF and underwater noise emitted from operating marine energy devices[12]
  • the physical presence of marine energy projects and their potential to alter the behavior of marine mammals, fish, and seabirds with attraction or avoidance
  • the potential effect on nearfield and farfield marine environment and processes such as sediment transport and water quality[13]

The Tethys database provides access to scientific literature and general information on the potential environmental effects of marine energy.[14]

See also


  1. ^ Carbon Trust, Future Marine Energy. Results of the Marine Energy Challenge: Cost competitiveness and growth of wave and tidal stream energy, January 2006
  2. ^ "Ocean—potential". International Energy Agency (IEA). Archived from the original on 22 May 2015. Retrieved 8 August 2016.
  3. ^ "Implementing Agreement on Ocean Energy Systems (IEA-OES), Annual Report 2007" (PDF). International Energy Agency, Jochen Bard ISET. 2007. p. 5. Archived (PDF) from the original on 1 July 2015.
  4. ^ "Indonesian Ocean Energy". Retrieved 5 April 2018.
  5. ^ "Tethys".
  6. ^
  7. ^ "Tethys".
  8. ^ "Tethys".
  9. ^
  10. ^
  11. ^ "Dynamic Device - Tethys". Retrieved 5 April 2018.
  12. ^ "EMF - Tethys". Retrieved 5 April 2018.
  13. ^ "Tethys".
  14. ^ "Tethys". Archived from the original on 10 November 2014.

Further reading

External links

Aquamarine Power

Aquamarine Power was a wave energy company, which was founded in 2005 to commercialise a wave energy device concept known as the Oyster wave energy converter. The company's head offices were based in Edinburgh. The company had further operations in Orkney, Ireland, Northern Ireland and the United States. Its chief executive officer was Martin McAdam, who joined the company in 2008. The company was advised by Trevor Whittaker, inventor of the Oyster concept, and Stephen Salter, inventor of the Salter's Duck.

The company ceased to trade on 20 November 2015.

Deep ocean water

Deep ocean water (DOW) is the name for cold, salty water found deep below the surface of Earth's oceans. Ocean water differs in temperature and salinity. Warm surface water is generally saltier than the cooler deep or polar waters; in polar regions, the upper layers of ocean water are cold and fresh. Deep ocean water makes up about 90% of the volume of the oceans. Deep ocean water has a very uniform temperature, around 0-3 °C, and a salinity of about 3.5% or as oceanographers state as 35 ppt (parts per thousand).In specialized locations such as the Natural Energy Laboratory of Hawaii NELHA ocean water is pumped to the surface from approximately 900 metres (3000 feet) deep for applications in research, commercial and pre-commercial activities. DOW is typically used to describe ocean water at sub-thermal depths sufficient to provide a measurable difference in water temperature.

When deep ocean water is brought to the surface, it can be used for a variety of things. Its most useful property is its temperature. At the surface of the Earth, most water and air is well above 3 °C. The difference in temperature is indicative of a difference in energy. Where there is an energy gradient, skillful application of engineering can harness that energy for productive use by humans. Assuming the source of deep ocean water is environmentally friendly and replenished by natural mechanisms, it forms a more innovative basis for cleaner energy than current fossil-fuel-derived energy.

The simplest use of cold water is for air conditioning: using the cold water itself to cool air saves the energy that would be used by the compressors for traditional refrigeration. Another use could be to replace expensive desalination plants. When cold water passes through a pipe surrounded by humid air, condensation results. The condensate is pure water, suitable for humans to drink or for crop irrigation. Via a technology called Ocean thermal energy conversion, the temperature difference can be turned into electricity.

Deep water source cooling

Deep water source cooling (DWSC) or deep water air cooling is a form of air cooling for process and comfort space cooling which uses a large body of naturally cold water as a heat sink. It uses water at 4 to 10 degrees Celsius drawn from deep areas within lakes, oceans, aquifers or rivers, which is pumped through the one side of a heat exchanger. On the other side of the heat exchanger, cooled water is produced.

European Marine Energy Centre

The European Marine Energy Centre (EMEC) Ltd is a UKAS accredited test and research centre focusing 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 unrivalled wave and tidal conditions. The operations are spread over five sites:

Billia Croo wave energy test site, Mainland (wave power)

Fall of Warness tidal energy test site, off the island of Eday (tidal power)

Scale wave test site at Scapa Flow, off St Mary’s Bay

Scale tidal test site at Shapinsay Sound, off Head of Holland

Stromness (office and data facilities)EMEC was established by a grouping of public sector organisations following a recommendation by the House of Commons Science and Technology Committee in 2001. In addition to providing access to areas of sea with high wave and tidal energy potential, the centre also offers various kinds of support regarding regulatory issues, grid connection and meteorological monitoring as well as local research and engineering support.

Global Marine Systems

Global Marine Group is a British-headquartered specialist provider of installation, maintenance and repairs of submarine communications cable for the telecommunications, oil & gas and deep sea research industries.

Global Marine provides engineering and underwater services in response to the subsea cable installation, maintenance and burial requirements of their customers around the world. With a fleet of vessels, ROVs and specialised subsea trenching and burial equipment, Global Marine works in the Oil & Gas, Telecom and Deep Sea Research sectors.

Global Marine, the legacy of Cable & Wireless Marine and British Telecom Marine, was purchased by Global Crossing in 1999, at which time it received the name it carries today. In 2004 Global Marine Systems was purchased by Bridgehouse Marine and was completely restructured. In September 2014 Global Marine was acquired by HC2. Historically, the company has a legacy of over 160 years of cable installation, stemming from the first telegraph cables laid in the 1850s.

Global Marine has a worldwide presence, with offices in Chelmsford, UK and Singapore; depots in Portland, UK; Bermuda; Vancouver, Canada; Batangas, Philippines and Batam, Indonesia; Ships are stationed around the world to support both installation of new cables and the maintenance and protection of existing cables. The company is also involved in joint ventures with China Telecom and Huawei.Since 2002 Global Marine has become increasingly active in the installation of submarine power cables and gained significant market share in the European Offshore Renewables market, in addition to undertaking a number of large power interconnect projects. The company was responsible for installing the cables connecting the turbines on a host of windfarm projects including Blythe (one of the first trial farms), Horns Rev 1 (the first major commercial windfarm in Denmark), Thornton Bank, Kentish Flats and others. To support this business Global Marine formed a subsidiary in 2011 called Global Marine Energy. The development of the energy business included the opening of a new office in Middlesbrough and the construction of a specialist vessel, Cable Enterprise. The subsidiary company was sold to Prysmian Group, the world’s largest cable manufacturer at the time of sale, in September 2012.

Global Marine today focuses primarily on supporting the telecoms, oil & gas and deep sea research markets.

International Electrotechnical Commission

The International Electrotechnical Commission (IEC; in French: Commission électrotechnique internationale) is an international standards organization that prepares and publishes international standards for all electrical, electronic and related technologies – collectively known as "electrotechnology". IEC standards cover a vast range of technologies from power generation, transmission and distribution to home appliances and office equipment, semiconductors, fibre optics, batteries, solar energy, nanotechnology and marine energy as well as many others. The IEC also manages four global conformity assessment systems that certify whether equipment, system or components conform to its international standards.

All electrotechnologies are covered by IEC Standards, including energy production and distribution, electronics, magnetics and electromagnetics, electroacoustics, multimedia, telecommunication and medical technology, as well as associated general disciplines such as terminology and symbols, electromagnetic compatibility, measurement and performance, dependability, design and development, safety and the environment.

List of Orkney islands

This is a list of Orkney islands in Scotland. The Orkney archipelago is located 16 kilometres (9.9 mi) north of mainland Scotland and comprises over 70 islands and skerries, of which 20 are permanently inhabited. In addition to the Orkney Mainland there are three groups of islands. The North and South Isles lie respectively north and south of Mainland. The Pentland Skerries are a group of small islands in the Pentland Firth, a dangerous stretch of water between mainland Scotland and the larger islands of Orkney, through which run the strongest tidal streams in Britain. The Island of Stroma is often mistakenly included with the Orkney Islands, but is part of Caithness.

The definition of an island used in this list is that it is 'land that is surrounded by seawater on a daily basis, but not necessarily at all stages of the tide, excluding human devices such as bridges and causeways'. There are four islands joined to the Orkney Mainland by a series of causeways known as the Churchill Barriers. They are South Ronaldsay, Burray, Lamb Holm and Glimps Holm. In addition, Hunda is connected to Burray by a causeway. The barriers were constructed by Italian prisoners-of-war as a means of preventing enemy submarine access to the vast natural harbour of Scapa Flow after the sinking of HMS Royal Oak by a German U-boat in 1939 with the loss of 883 lives. The Italian prisoners constructed a small Roman Catholic chapel on Lamb Holm as a place of worship during their incarceration.Most of the islands have a bedrock formed from Old Red Sandstone, which is about 400 million years old, and was laid down in the Devonian period. The islands have good agricultural qualities and have been continuously inhabited for thousands of years, as evidenced by the World Heritage Site of the Heart of Neolithic Orkney. The archipelago is exposed to wind and tide, and there are numerous lighthouses as an aid to navigation. The European Marine Energy Centre, which is located at Stromness, is currently testing various wave and tidal energy devices from Billia Croo on the Mainland and Eday. The islands all fall within the Orkney Islands Council area. Most of the larger islands have development trusts that support the local economy.The total population of Orkney increased from 19,245 in 2001 to 21,349 at the time of the 2011 census.

Marine current power

Marine currents can carry large amounts of energy, largely driven by the tides, which are a consequence of the gravitational effects of the planetary motion of the Earth, the Moon and the Sun. Augmented flow velocities can be found where the underwater topography (bathymetry) in straits between islands and the mainland or in shallows around headlands plays a major role in enhancing the flow velocities, resulting in appreciable kinetic energy. The sun acts as the primary driving force, causing winds and temperature differences. Because there are only small fluctuations in current speed and stream location with minimal changes in direction, ocean currents may be suitable locations for deploying energy extraction devices such as turbines. Other effects such as regional differences in temperature and salinity and the Coriolis effect due to the rotation of the earth are also major influences. The kinetic energy of marine currents can be converted in much the same way that a wind turbine extracts energy from the wind, using various types of open-flow rotors.

Ocean dynamics

Ocean dynamics define and describe the motion of water within the oceans. Ocean temperature and motion fields can be separated into three distinct layers: mixed (surface) layer, upper ocean (above the thermocline), and deep ocean.

Ocean dynamics has traditionally been investigated by sampling from instruments in situ.The mixed layer is nearest to the surface and can vary in thickness from 10 to 500 meters. This layer has properties such as temperature, salinity and dissolved oxygen which are uniform with depth reflecting a history of active turbulence (the atmosphere has an analogous planetary boundary layer). Turbulence is high in the mixed layer. However, it becomes zero at the base of the mixed layer. Turbulence again increases below the base of the mixed layer due to shear instabilities. At extratropical latitudes this layer is deepest in late winter as a result of surface cooling and winter storms and quite shallow in summer. Its dynamics is governed by turbulent mixing as well as Ekman pumping, exchanges with the overlying atmosphere, and horizontal advection.The upper ocean, characterized by warm temperatures and active motion, varies in depth from 100 m or less in the tropics and eastern oceans to in excess of 800 meters in the western subtropical oceans. This layer exchanges properties such as heat and freshwater with the atmosphere on timescales of a few years. Below the mixed layer the upper ocean is generally governed by the hydrostatic and geostrophic relationships. Exceptions include the deep tropics and coastal regions.

The deep ocean is both cold and dark with generally weak velocities (although limited areas of the deep ocean are known to have significant recirculations). The deep ocean is supplied with water from the upper ocean in only a few limited geographical regions: the subpolar North Atlantic and several sinking regions around the Antarctic. Because of the weak supply of water to the deep ocean the average residence time of water in the deep ocean is measured in hundreds of years. In this layer as well the hydrostatic and geostrophic relationships are generally valid and mixing is generally quite weak.


Orkney (Old Norse: Orkneyjar), 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, Mainland, is often referred to as "the Mainland", and 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. The largest settlement and administrative centre is Kirkwall.Orkney is one of the 32 council areas of Scotland, a constituency of the Scottish Parliament, a lieutenancy area, and a historic county. The local council is Orkney Islands Council, one of only three Councils in Scotland with a majority of elected members who are independents.A form of the name dates to the pre-Roman era. The islands have been inhabited for at least 8,500 years, originally occupied by Mesolithic and Neolithic tribes and then by the Picts. Orkney was colonised and later annexed by Norway in 875 and settled by the Norse. The Scottish Parliament then absorbed the earldom to the Scottish Crown in 1472, following the failed payment of a dowry for James III's bride Margaret of Denmark.In addition to the Mainland, most of the remaining islands are in two groups, the North and South Isles, all of which have an underlying geological base of Old Red Sandstone. The climate is mild and the soils are extremely fertile, most of the land being farmed. Agriculture is the most important sector of the economy. The significant wind and marine energy resources are of growing importance, and the island generates more than its total yearly electricity demand using renewables. The local people are known as Orcadians and have a distinctive dialect of the Scots language and a rich inheritance of folklore. Orkney contains some of the oldest and best-preserved Neolithic sites in Europe, and the "Heart of Neolithic Orkney" is a designated UNESCO World Heritage Site. There is an abundance of marine and avian wildlife.

Oyster wave energy converter

The Oyster is a hydro-electric wave energy device that uses the motion of ocean waves to generate electricity. It is 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 is stationed at the European Marine Energy Centre (EMEC) at its Billia Croo site in Orkney, Scotland.

Aquamarine Power installed Oyster at the EMEC in August 2009. On 20 November 2009, Oyster was officially launched and connected to the National Grid (UK) by the First Minister of Scotland, Alex Salmond.Current developments are underway to build a more efficient and powerful second-generation device, Oyster 2.

Pacific Marine Energy Center

Pacific Marine Energy Center (PMEC), formerly known as the Northwest National Marine Renewable Energy Center (NNMREC), is a partnership between Oregon State University, the University of Washington, and the University of Alaska Fairbanks. Oregon State University focuses on wave energy. University of Washington focuses on tidal energy. The three universities collaborate with each other on research, education, outreach, and engagement.

Partners in PMEC include:

National Renewable Energy Laboratory

Pacific Northwest National Laboratory

Public Utility District of Snohomish County No. 1

BioSonics, Inc.

Electric Power Research Institute

Verdant Power

Pacific Northwest Economic Region

Sound & Sea Technology

National Marine Fisheries Service

Washington Department of Ecology

Pelamis Wave Energy Converter

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.

Developed by the now defunct

Scottish company Pelamis Wave Power (formerly Ocean Power Delivery), the Pelamis became the first offshore wave machine to generate electricity into the grid, when it was first connected to the UK grid in 2004. Pelamis Wave Power then went on to build and test five additional Pelamis machines: three first-generation P1 machines, which were tested in a farm off the coast of Portugal in 2009, and two second-generation machines, the Pelamis P2, were tested off Orkney between 2010 and 2014. The company went into administration in November 2014, with the intellectual property transferred to the Scottish Government body Wave Energy Scotland.

Pelamis Wave Power

Pelamis Wave Power designed and manufactured the Pelamis Wave Energy Converter – a technology that uses the motion of ocean surface waves to create electricity. The company was established in 1998 and had offices and fabrication facilities in Leith Docks, Edinburgh, Scotland. It went into administration in November 2014.

Power station

A power station, also referred to as a power plant or powerhouse and sometimes generating station or generating plant, is an industrial facility for the generation of electric power. Most power stations contain one or more generators, a rotating machine that converts mechanical power into three-phase electric power. The relative motion between a magnetic field and a conductor creates an electric current. The energy source harnessed to turn the generator varies widely. Most power stations in the world burn fossil fuels such as coal, oil, and natural gas to generate electricity. Cleaner sources include nuclear power, biogas and an increasing use of renewables such as solar, wind, wave and hydroelectric.

Saltire Prize

The Saltire Prize, named after the flag of Scotland, is the national award for advances in the commercial development of marine energy.

To be considered for the £10 million award teams must demonstrate, in Scottish waters, a commercially viable wave or tidal stream energy technology "that achieves the greatest volume of electrical output over the set minimum hurdle of 100GWh over a continuous 2 year period using only the power of the sea."

The Saltire Prize is open to any individual, team or organisation from across the world who believes they have wave or tidal energy technology capable of fulfilling the challenge. Applications can be submitted between March 2010 and January 2015. Already there are five competitors registered.

Scottish Renewables

Scottish Renewables is the representative body of the Scottish renewable energy industry. Since 1996, it has aimed to present a united voice to decision makers who make energy policy. Scottish Renewables represents over 300 members and member organisations are wide ranging across all technologies and supply chains. Scottish Renewables has developed 14 focus areas to fully represent the renewable energy industry. These include: offshore wind power, onshore wind power, bioenergy, heat, hydro, marine energy, and microgeneration.Johanna Yates, offshore policy manager for Scottish Renewables, has said Scotland is the natural home to offshore renewable energy, with abundant natural resources and long heritage of maritime industry – principally oil and gas and fisheries. Scotland’s potential is well known and in recent months there has been investment from significant international players, such as Doosan, Mitsubishi and Gamesa, all vying to establish their wind turbines in Scottish waters. Future employment for offshore wind projects is promising, with up to 28,000 direct jobs being created by 2020, leading to an economic input of £7 billion.

Wave power

Wave power is the capture of energy of wind waves to do useful work – for example, electricity generation, water desalination, or pumping water. A machine that exploits wave power is a wave energy converter (WEC).

Wave power is distinct from tidal power, which captures the energy of the current caused by the gravitational pull of the Sun and Moon. Waves and tides are also distinct from ocean currents which are caused by other forces including breaking waves, wind, the Coriolis effect, cabbeling, and differences in temperature and salinity.

Wave-power generation is not a widely employed commercial technology compared to other established renewable energy sources such as wind (Wind Turbine) and solar (Photovoltaic), however, there have been attempts to use this source of energy since at least 1890 mainly due to its highest power density. As a comparison, the power density of the photovoltaic panels is 1 kW/m2 at peak solar insolation, and the power density of the wind is 1 kW/m2 at 12 m/s for a General Electric (GE) 1.5 MW machine. Whereas, the average annual power density of the waves at e.g. San Francisco coast is 25 kW/m.In 2000 the world's first commercial Wave Power Device, the Islay LIMPET was installed on the coast of Islay in Scotland and connected to the National Grid. In 2008, the first experimental multi-generator wave farm was opened in Portugal at the Aguçadoura Wave Park.


Wärtsilä Oyj Abp (Finnish: [ˈʋærtsilæ]) is a Finnish corporation which manufactures and services power sources and other equipment in the marine and energy markets. The core products of Wärtsilä include technologies for the energy sector, including gas, multi-fuel, liquid fuel and biofuel power plants and energy storage systems; and technologies for the marine sector, including cruise ships, ferries, fishing vessels, merchant ships, navy ships, special vessels, tugs, yachts and offshore vessels. Ship design capabilities include ferries, tugs, and vessels for the fishing, merchant, offshore and special segments. Services offerings include online services, underwater services, turbocharger services, and also solutions for the marine, energy, and oil and gas markets. At the end of June 2018, the company employed more than 19,000 workers.Wärtsilä has two main businesses; Energy Business focusing on the energy market, and Marine Business focusing on the marine market. The Marine Business is mainly present in Europe, China and East Asia, while its key Energy Business markets are South and South East Asia, Middle East, Africa and Latin America. Wärtsilä has locations in around 80 countries but operates globally.The company has signaled its intention to transform from an equipment maker to a Smart Marine and Energy company, following acquisitions of companies such as Transas, Greensmith, Guidance Marine, and MSI, and the setting up of Digital Acceleration Centres in Helsinki, Singapore, Central Europe, and North America.

Fundamental concepts
Energy carriers
Primary energy
Energy system
Use and
Wave power
Tidal power
Failure modes
and policies
Statistics and Production
Ocean zones
Sea level


This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.