Tidal power or tidal energy is harnessed by converting energy from tides into useful forms of power, mainly electricity using various methods.
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).
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 National Institute of Ocean Technology (NIOT) was established in November 1993 as an autonomous society under the Ministry of Earth Sciences in India. NIOT is managed by a Governing Council and is headed by a director. The institute is based in Chennai. The major aim of starting NIOT was to develop reliable indigenous technologies to solve various engineering problems associated with harvesting of non-living and living resources in India's exclusive economic zone, which is about two-thirds of the land area of India.
The Wave Hub is a floating offshore wind and wave power research project. The project is developed approximately 10 miles (16 km) off Hayle, on the north coast of Cornwall, United Kingdom. The hub was installed on the seabed in September 2010, and is a 'socket' sitting on the seabed for wave energy converters to be plugged into. It will have connections to it from arrays of up to four kinds of wave energy converter. A cable from the hub to main land will take electrical power from the devices to the electric grid. The total capacity of the hub will be 20 MWe. The estimated cost of the project is £28 million.
CETO is a wave-energy technology that converts kinetic energy from ocean swell into electrical power and directly desalinates freshwater through reverse osmosis. The technology was developed and tested onshore and offshore in Fremantle, Western Australia. In early 2015 a CETO 5 production installation was commissioned and connected to the grid. As of January 2016 all the electricity generated is being purchased to contribute towards the power requirements of HMAS Stirling naval base at Garden Island, Western Australia. Some of the energy will also be used directly to desalinate water.
The European Marine Energy Centre (EMEC) Ltd is a UKAS accredited test and research center 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.
A floating wind turbine is an offshore wind turbine mounted on a floating structure that allows the turbine to generate electricity in water depths where fixed-foundation turbines are not feasible. Floating wind farms have the potential to significantly increase the sea area available for offshore wind farms, especially in countries with limited shallow waters, such as Japan, France and the United States' West Coast. Locating wind farms further offshore can also reduce visual pollution, provide better accommodation for fishing and shipping lanes, and reach stronger and more consistent winds.
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.
Ocean Power Technologies (OPT) is a U.S. publicly owned renewable energy company, providing electric power and communications solutions, services and related for remote offshore applications. The company's PowerBuoy wave energy conversion technology is theoretically scalable to hundreds of megawatts and the generated energy from wave power can be supplied to the grid via submarine cables. Several projects were undertaken around the world, but the economic viability of the theoretical concept has been problematic.
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 was stationed at the European Marine Energy Centre (EMEC) at its Billia Croo site in Orkney, Scotland until the company ceased trading in 2015.
Marine energy or marine power 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 Lysekil project is an ongoing wave power project which is run by the Centre for Renewable Electric Energy Conversion at Uppsala University in Sweden.
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 run of 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.
DNV is an international accredited registrar and classification society headquartered in Høvik, Norway. The company currently has about 12,000 employees and 350 offices operating in more than 100 countries, and provides services for several industries including maritime, oil and gas, renewable energy, electrification, food and beverage, and healthcare. DNV GL was created in 2013 as a result of a merger between two leading organizations in the field — Det Norske Veritas (Norway) and Germanischer Lloyd (Germany). In 2021, DNV GL changed its name to DNV, while retaining its post-merger structure.
Wave power in the United States is under development in several locations off the east and west coasts as well as Hawaii. It has moved beyond the research phase and is producing reliable energy for the Grid. Its use to-date has been for situations where other forms of energy production are not economically viable and as such, the power output is currently modest. But major installations are planned to come on-line within the next few years.
Oscillating water columns (OWCs) are a type of wave energy converter that harness energy from the oscillation of the seawater inside a chamber or hollow caused by the action of waves. OWCs have shown promise as a renewable energy source with low environmental impact. Because of this, multiple companies have been working to design increasingly efficient OWC models. OWC are devices with a semi-submerged chamber or hollow open to the sea below, keeping a trapped air pocket above a water column. Waves force the column to act like a piston, moving up and down, forcing the air out of the chamber and back into it. This continuous movement forces a bidirectional stream of high-velocity air, which is channeled through a power take-off (PTO). The PTO system converts the airflow into energy. In models that convert airflow to electricity, the PTO system consists of a bidirectional turbine. This means that the turbine always spins the same direction regardless of the direction of airflow, allowing for energy to be continuously generated. Both the collecting chamber and PTO systems will be explained further under "Basic OWC Components."
MARMOK-A-5 is an offshore electrical power generator that uses wave energy to create electricity. This device is a spar buoy installed in the maritime testing site Bimep, in the Bay of Biscay. It is the first grid-connected maritime generator in Spain, and one of the first in the world.
Sotenäs is a wave farm located in Kungshamn, in the municipality of Sotenäs, Sweden. The facility consists of 36 wave energy converters (WECs), with a total installed capacity of nearly 3 MW. Each WEC generates power using point absorber buoys connected to linear generators on the seabed. The generators are located at a depth of 50 m (160 ft). According to Seabased, the technology used in the project could deliver electricity for under 10 cents per kWh. Initial announcements stated that the power plant would eventually expand to around 10 MW capacity, but in 2017 Seabased announced it would no longer expand the plant beyond the 36 WECs already in place.
