Marine Wave Energy electricity generation - a painfully slow development - in which the Scots have a lead
The expenditure of more money and effort has resulted in some real marine wave power electricity generating systems being built and trials completed. Some projects now hover on the edge of commercial development. A background article produced by the expensively Government funded Carbon Trust provide a very simple explanation of some of the principles and design features invloved and can be found here.
The Aguçadoura project off the coast of northern Portugal, a 250-350-kilometer (150-220 mile) stretch of coast has been identified as a suitable location for wave-energy exploitation .As a consequence Portugal has established its role as a pioneer in such systems and the Instituto Superior Técnico has been studying the technology since 1977.
We posted about the Scottish designed and manufactured system - Thursday, June 09, 2005
First Commercial Wave farm for Portugal Ocean Power Delivery (OPD) were conrtracted to build the wave farm about five kilometers (3.1 miles) off Portugal's northern coast, near Povoa de Varzim, OPD's Norwegian backer Norsk Hydro said.
Portuguese Enersis SGPS, part of the Semapa Corporation, is one of Portugal’s leading renewable energy companies with 100MW of mini hydro, 500MW of wind farms under operation/construction and a further 500MW under development had initiated the project.
They were to install three wave power generation units with capacity of 2.25 Mw for 8 million euros ($10.12 million), but the project could be expanded significantly.
OPD's Pelamis P-750 wage energy converter is an elongated metal unit that looks like a big semi-submerged sausage, with hinged segments that rock with the sea, up and down and side to side, pumping fluid to hydraulic motors that drive generators.
Based in Edinburgh, Scotland, OPD (www.oceanpd.com) has been developing the Pelamis technology for the past 7 years. They have been supported by the UK DTI (now BERR) and its investors including Norsk Hydro Technology Ventures, Sustainable Asset Management, the Carbon Trust and 3i plc, the prototype for the Portuguese machines was launched in February 2004 and was under initial tests at the European Marine Energy Centre, Orkney, Scotland
The deal with Enersis included a letter of intent for a further 30 Palamis wave machines for a total of 20 megawatts before the end of 2006, subject to satisfactory performance by the initial installation, Hydro said. This says the company is "world’s first, multi-unit, wave farm and also the first commercial order for wave energy converters"
Anyway after some alarums and excursions, Enersis and ODP, now called Pelamis Wave Power (PWP) ,completed initial deployment of a 750-kW PWP wave-power unit, in August 2008, that generated electricity for the Portuguese grid.
The unit initially encountered difficulties with buoyancy, this required a return to habour for repairs - resulting in the designers putting a brave face on it saying "that it has since been disconnected to prove it can be returned to harbor for inspection of the component parts. "Everything is in very good order."
The Aguçadoura project partners are looking to have the three 750-kW machines ready by September 2008. The Portuguese government is supporting the project by a feed-in tariff provided specifically for marine energy of about €0.23/kWh (US36¢/kWh), according to PWP's Web site.
Whilst wwait for some commercial results other companies are eyeing up Portugal including developers Tecdragon, EDP and Eneólica. The Portuguese steel construction giant Martifer has created a joint marine-energy venture with Scottish Briggs, while Generg conducts research and planning for a wave energy plant.
EDP, Portugal's largest power utility, is in the final stages of talks to install wave energy demonstration after looking at 50 different design. Now, final site selection has begun on the Breakwave, a system financed with €2.4 Mn. of European Union funds that exploits oscillating water column technology. This will have 3 turbines and two generators one of 500kW and one 250kW and the total cost is €2.4 Mn.
A more advance technique is More advanced is Tecdragon, which they aim to install in Portugal's São Pedro de Moel pilot zone the first world's 7-MW wave-energy plant. But, Tecdragon Manager Borges da Cunha explains "Until now the start of installation was not possible due to adverse meteorological conditions." Another delay which seems to be a familiar problem with wave energy systems.
The system is based on what they call Wave Dragon technology, which the company describes as a "floating, slack-moored energy converter" that meshes current offshore and hydropower turbine technology.
They claim Wave Dragon, is the only wave energy converter being developed that can be freely scaled up. Extravagant claims of future performance are another feature of wave technology companies. It has been developed with funding support from the European Union, the Welsh Development Agency, the Danish Energy Authority and the Danish Utilities PSO Programme.
So far, a 1:4.5 scale prototype launched in 2003 was the world’s first offshore grid-connected wave energy conversion device. Deployed off the coast of Denmark at Nissum Bredning, this test unit accumulated over 20,000 (there are 8,700 in a year) hours of experience supplying electricity to domestic homes.
Another demonstration unit with a capacity of 7 MW, this unit will be built at Pembroke Dock, Wales. This will eventually be located two to three miles off St Ann’s Head and tested for three to five years only, in order to gain operational experience and knowledge of energy transfer efficiencies. This is supposed to be operating this summer.
The Wave Dragon produces energy in almost exactly the same way as a low-head hydro power station.
The Unit is a slack (ie can move fairly freely) tethered floating barge which faces its outstretched collector arms towards the oncoming waves. These concentrate 300 metres of wave front towards 140 metres of ramp at the front of the structure.
Focussing the waves increases the wave height at the ramp, which in turn acts like a beach and causes the waves to break over its top and into the reservoir behind it. (see pic By this action the water is elevated and given potential energy, runs through the turbines and generates electricity.
The Scottish Nation take a leap
The UK wave power sector took a surprise turn on July 30 when Jim Mather, minister of enterprise and energy for the Scottish regional government, commissioned a 100-kw Wavegen turbine. Wavegen is a wholly owned company of Voith Siemens Hydro Power Generation. Press release. BBC report with video of Islay LIMPET project.
Scotland is said to offer developers some of the world's best wave-power levels and has already seen the demise of one expensive project.
The 100-kW turbine is "a major step forward," the Scottish government said, for the Siadar Wave Energy Project (SWEP) . The SWEP is based upon the Oscillating Water Column (OWC) principle and is being developed by Npower Renewables (who say this is an "exciting" scheme) , RWE Innogy's UK operating company, on the Scottish Isle of Lewis.
This project will receive support (amount is confidential) from the Scottish Government’s WATES (Wave and Tidal Energy Support) scheme.
Npower Renewables submitted planning applications in April for SWEP, which would generate up to 4 MW using 40 Wavegen 100-kW turbines.
If the Scottish government approves the plans, construction could start as early as 2009 . The project could generate up to 50 construction jobs for local people and would take 18 months to complete said Mr Mather.
The Dutch company Tocardo has confirmed it isplanning to build a tidal energy plant in the Pentland Firth. BBC
The Pentland Firth is a stretch of open water about 20 miles wide between the Caithness coast and the Orkney Islands. It is arguably one of the best concentrated tidal resources on earth. Estimates of the energy potential in this few square kilometres range from 2GW to 8GW.
An objective has been set by public sector agencies and the Scottish Government to harness 1300MW of tidal energy in the Pentland Firth by 2020.
The Highlands and Islands Energy Board (HIE) is working closely with the Pentland Firth Tidal Energy Board to capitalize on the tremendous marine energy opportunities in the area.
The European Marine Energy Centre (EMEC) in Orkney, is (they say) a key infrastructure that "provides a ground breaking contribution to advancing the marine energy industry in Scotland."
EMEC was established at a cost of approximately £15 million, funded by HIE, the Scottish Government, Department of Business, Enterprise and Regulatory Reform, the Carbon Trust, Scottish Enterprise and Orkney Islands Council.
The wave and tidal test centres are now well established and the first tidal device was generating electricity for the grid by the end of May 2008.
AWS Ocean Energy based in Alness, Ross-shire established in 2004 , is also using the local seas to develop and test its revolutionary utility-scale Archimedes Wave Swing technology. The company is another developer awarded funding through the Scottish Government's Wave and Tidal Energy Support Scheme, and is aiming to deploy a prototype device at EMEC in 2009.Their award winning Archimedes Waveswing™ is also an "exciting technology" ...clean renewable energy ... global energy needs .. er ... a sustainable basis.
They say they will deploy a 250kW demonstrator in 2009 with commercial roll-out to follow by 2011.
Archimedes Waveswing™ is wave energy converter. They explain that this is a cylinder shaped buoy, moored to the seabed. Passing waves move an air-filled upper casing against a lower fixed cylinder, with up and down movement converted into electricity.
As a wave crest approaches, the water pressure on the top of the cylinder increases and the upper part or 'floater' compresses the gas within the cylinder to balance the pressures.
The reverse happens as the wave trough passes and the cylinder expands. The relative movement between the floater and the lower part or silo is converted to electricity by means of a hydraulic system and motor-generator set.
Their investors include Rab Capital PLC www.rabcap.com .
Isleburn Group www.isleburn-mm.com Isleburn are a medium sized engineering, fabrication and construction group with considerable experience in offshore engineering and will assemble the AWS units.
Tersus Energy PLC www.tersusenergy.com Tersus is a clean energy investment company quoted on Aim in London and is focused upon the renewable energy and energy efficiency sectors.
STV Fund , managed by Kenda Capital B.V., selectively focuses on renewable energy technologies that show significant promise of delivering cost-competitive energy, they possess a solid energy sector expertise, fostered through its technology relationship with the Shell Group. Terry Rhodes is a Non-executive Director and is also Head of Offshore Structures at Shell Exploration and Production UK Ltd.
The Tudor Group , which consists of Tudor Investment Corporation are money jugglers.
Scotland's First Minister Alex Salmond announced plans for the world's largest wave farm when he opened EMEC in September 2007. This project is being led by CRE Ltd and will consist of 4r 750kW Pelamis devices off the coast of Orkney. It is hoped that this farm will be operational in summer 2009... which seems highyl unlikely considering the delays and problems Pelamis have experienced in Portugal at Aguçadoura.