Ocean energy can play important role in renewable resources mix

June 25, 2011 by  
Filed under Ocean Energy

Comments Off on Ocean energy can play important role in renewable resources mix

Renewable technologies could supply the world with more energy than it would ever need and at a very competitive cost, avers Steve Sawyer, secretary-general of the Global Wind Energy Council.

He adds that ocean energy may play a very important role in the future. Ocean energy derives from the potential, kinetic, thermal and chemical energy of seawater, which can be transformed to provide electricity, thermal energy or potable water.

According to the Intergovernmental Panel on Climate Change (IPCC) report published recently, several technologies are possible, such as submarine turbines for tidal and ocean currents, heat exchangers for ocean thermal energy conversion, and a variety of devices to harness the energy of waves and salinity gradients.

Ocean technologies, with the exception of tidal barrages, are at the demonstration and pilot project phases and many require additional research and development. Some of the technologies have variable energy output profiles with differing levels of predictability (for instance, wave, tidal range and current), while others may be capable of near-constant or even controllable operation (for instance, ocean thermal and salinity gradient).

Tidal Power Plant in Northern Ireland
Sabine Sauter writes in Pictures of the Future about “tapping invisible rivers”.  Tidal flows represent a largely untapped source of clean energy.

Located off the coast of Northern Ireland, the world’s first commercial tidal current power plant is producing electricity for 1 500 household using energy generated by high and low tides. The Strangford Lough plant is operated by Marine Current Turbines, a British company in which Siemens acquired a 10% interest in 2010. The facility is similar to a wind turbine, the only difference being that it is driven by water instead of air. Each of its two drivetrains weighs 27 t and is equipped with a rotor 16 m in diameter.

The rotor blades can be turned through 180º, which means they can produce electricity for up to 20 hours a day regardless of whether the tide is coming in or going out.

The tower to which the two propeller turbines are attached through a cross member has a diameter of 3 m. Depending on the tide, the tower can protrude as much as 20 m above the sea. The rotors cannot be seen above the water – and it is even possible to take a small boat directly past the turbine because the rotors are located at least 3 m below the surface.

Although extensive installation costs make an investment in tidal current power plants around twice as high as those for offshore wind power facilities, the resulting electricity offers several benefits. For example, the energy density of water is 800 times higher than that of wind, which makes gene- rating electricity with water much more efficient. A 1,2 MW tidal plant like the one at Strangford Lough can produce as much electricity in a year as a 2,5 MW offshore wind turbine. The electricity yield from tidal facilities is also more precisely calculatable, which enhances planning security. After all, tidal currents are determined by the moon and the earth’s gravity, so they are not dependent on the weather and can be predicted years in advance.

The International Energy Agency estimates the global output potential of tidal power plants to be as high as 800 TWh/y, which is enough to supply 250-million households with electricity.

Marine Current Turbines continues to invest in tidal technologies. Besides other things, the company plans to start building a tidal turbine park near the Isle of Skye, in north-eastern Scotland, in 2013.

When it is complete, the facility will supply up to 4 000 households with electricity from the sea.

Ocean Energy on the Verge of Rapid Growth?

January 6, 2011 by  
Filed under Ocean Energy

Is the global ocean energy industry at a turning point? With all the attention focused on energy efficiency and smart grid, and with more mature renewable sectors like wind struggling, we haven’t heard much about ocean energy in the last year or two.

Financing is tight and venture capital is extra-cautious as the world struggles to get through this tough recession. It’s not the best time for a new industry to gain footing.

High initial costs and long development lead times makes the industry dependent on government support. Ocean energy has received much less support than solar or wind, but that could change. Costs are high because prototypes must stand up to ocean storms, and in the U.S. they must navigate a confusion of overlapping offshore permitting authorities.

After only a dozen wave and tidal prototypes were installed in 2009, more than 45 projects will have been tested in 2010 and 2011, according to IHS Emerging Energy Research. If these prototypes are successful, IHS believes the global ocean energy project pipeline is poised to begin scaling. They estimate that more than 1.8 GW of ocean projects in 16 countries are currently in the pipeline.

Ocean Energy

Could Ocean Energy be Problematic for Marine Life?

But concerns are surfacing that the electro-magnetic fields created by tide and wave generators (and the cables that bring their electricity to shore) could interfere with the natural guidance systems used by marine life.

Salmon, sharks, sea turtles, lobsters and crabs are among the marine life that use internal compasses that rely on the Earth’s magnetic fields. They travel thousand of miles each year using the earth’s magnetic fields to navigate. Ocean energy machines might also produce a low hum that could interfere with communication among whales. It’s long been known that the use of military sonar poses a deadly threat to whales, many of which have been found dead or dying following massive sonic blasts.

Research hasn’t been done on how these power devices affect the marine environment.

Promise for Energy Supply

The Northwest Power Planning Council estimates ocean energy could eventually supply 10% of US energy, with 50,000 MW off the Northwest coast, equal to the output of 50 nuclear plants.

Other sites under consideration are off the coast of Maine, Hawaii, Alaska, Florida and in the Mississippi River near Baton Rouge.

Thanks to government policy support, the UK holds the lead in ocean energy – 300 MW of projects are in the pipeline to be installed over the next five years. The UK wants to add 1.3 GW by 2020 to help meet its legally binding 2020 renewable targets. Ireland, France, Portugal, South Korea and Australia are also key ocean energy markets and will remain the industry’s primary focus for the next decade, according to IHS.

And it’s not just tiny, start-ups that are pushing the field forward. A slew of established energy firms, including leading European utilities and global technology suppliers with hydro and offshore wind experience, are interested in establishing leadership positions.

Of the various forms of ocean energy, tidal energy is poised to mature first because it offers the promise of predictable, lower-cost electricity and a standard design.

“The strong synergies between tidal turbine manufacturing and the hydropower industry have attracted major power sector OEMs,” says IHS Senior Renewable Power Analyst Marianne Boust. “Over the past two years, all three of the major hydropower turbine vendors – Andritz Hydro, Alstom Hydro, and Voith Hydro – who account for over 80 percent of the global hydro turbine supply, have jumped into the tidal sector.”

Because these large hydro players see tidal energy as a synergistic growth opportunity, they are crucial to catalyzing quick development and commercialization of the tidal industry. They could help the ocean energy industry overcome its technological challenges and drive down costs.

Key companies that are active in scaling Europe’s offshore wind industry are also eyeing ocean energy as they scale their renewable portfolios. Iberdrola-ScottishPower, Vattenfall, RWE and SSE all have a strong presence in offshore wind. Each is broadening to include ocean energy. A few have taken equity stakes in ocean technology firms, but most are funding project development through joint ventures.

Ocean Power Technologies Leads

The only pure-play publicly traded company in ocean energy is Ocean Power Technologies (OPTT), which is developing the first commercial scale wave energy system in the US off the coast of Oregon. The 1.5MW wave energy system, which will power about 1000 homes, is expected to be deployed in 2011.

In September, OPTT received $4.8 million in funding from the US Department of Energy, on top of $2 million it received in 2008. They are using the funds to construct the Oregon project and to develop its next generation 500kW system, which will have greater power extraction efficiency. The company is also focused on implementing a “Design-for-Manufacture” approach and reducing maintenance costs, to achieve lower installed capital and energy costs and make wave power more competitive with fossil fuels.

Also in September, OPTT connected a wave energy device to the US grid for the first time at the US Navy’s Marine Corps Base in Hawaii. The connection demonstrates the ability of wave systems to produce utility-grade, renewable energy that can be transmitted to the grid.

The Navy has supported Ocean Power’s technology development through its $15 million Littoral Expeditionary Autonomous PowerBuoy (LEAP) program. OPTT is providing an autonomous wave energy conversion system for the Navy’s near-coast anti-terrorism and maritime surveillance program.

OPTT is also working with Mitsui Engineering Shipbuilding Co to apply its technology off the coast of Japan. In October 2009, a Japanese consortium signed a MOU to develop wave energy in Japan.


The IHS study, Global Ocean Energy Markets and Strategies: 2010-2030, analyzes the various ocean technologies and companies and the potential size and timing for ocean energy scaling.

Source: Sustainable Business

Wave energy ‘could create 52000 jobs’

January 5, 2011 by  
Filed under Ocean Energy

Wave energy 'could create 52,000 jobs' Nearly 70,000 jobs could be created if Ireland’s ocean energy sector is fully developed and meets the government’s 2020 renewable targets, a new report says.

According to SQW Energy’s Economic Study for Ocean Energy Development in Ireland, which was commissioned by the government’s Sustainable Energy Authority of Ireland and Invest Northern Ireland, wave energy could generate up to 52,000 employment positions, while tidal energy could result in 17,000 jobs, the Irish Times reported.

The all-Ireland ocean energy sector could be worth about EUR9 billion, the report suggests.

An “appropriate level of investment” in the sector could provide “long-term sustainable growth and wealth creation”, it added.

In November last year, An tSl Ghlas – The Green Way, which is composed of green industry firms, third level institutions and local authorities, predicted that Ireland’s green sector will create about 10,000 jobs over the next five years.

An tSl Ghlas, the country’s first green economic zone, is based in Dublin.

Marine Power Developers Getting Creative in Oregon (audio)

December 30, 2010 by  
Filed under Ocean Energy

Thu, December 30, 2010
Posted in Alaska News

Tom Banse, Northwest News Network

Alaska coastal communities that are considering the ocean for power might want to keep an eye on Oregon, where marine energy developers are looking for ways to make electricity from the sea.

The alternative energy sector has been slow to coalesce around one technology. In fact, unconventional ideas are blooming like algae. Northwest News Network Correspondent Tom Banse reports on the proliferation of creative electric engineering on the coast.

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Tidal energy the way forward, says expert

December 25, 2010 by  
Filed under Secrets of the Ocean


The creek network near Karachi has the potential to generate 8,000 megawatts (MW) of tidal energy at very cheap rates, which would be enough to end the severe power crisis the city of 18 million is facing, Dr Naseem A Khan, vice chancellor Hamdard University and former secretary Alternate Energy Board, told The News on Friday.

The Karachi Electric Supply Corporation (KESC) has an installed capacity of 1,700 MW and faces a shortfall of 500 MW, which it takes from the Water and Power Development Authority (Wapda), according to the vice chancellor.

The tidal energy generated from the creek network could become the base load and would be available for eight hours a day, he said.

Dr Khan, who has a PhD in engineering and is also an author, suggested that initially one should focus on data collection and involve local universities in that process. He said the second step must be the acquisition of the required technology, following which a feasibility report should be made.

Dr Khan believed that the project should be run by a public-private partnership. He said the project would cost $150 million and take time to become a reality, but it once does the people of Karachi would finally get rid of loadshedding.

Dr Khan said when he was secretary he made an elaborate proposal to the Alternate Energy Board. However, the government was reluctant to invest in the project despite the fact that a Turkish firm, Zorlu, was taking a keen interest in it.

He agreed that the oil lobby was so well entrenched in Pakistan that proposals for alternate energy were ignored. We have great potential for alternate energy and we also have enough human resources, but we lack initiative.

A study conducted by the National Institute of Oceanography (NIO) some 23 years ago suggested that the complex creeks network in the Indus Deltaic region, extending over an area of 170 kilometres along the 990-km coastline that Pakistan shares with the Arabian Sea, could generate 900 MW of affordable energy, which would be adequate to meet the power requirements of Karachi.

A team of scientists, led by Dr GS Quraishee, a former director general of NIO, conducted the two-year study but it was ignored by the countrys bureaucracy, apparently because the latter allegedly had a vested interest in producing energy through oil imports and enjoying huge kickbacks.

Tapping renewable energy from the ocean was becoming increasingly important, and one reason was that ocean energies were renewable and could not deplete, the study said. The other reason was that, unlike solar or wind power, which manifests itself in kilowatts, ocean energies were being debated and planned, in some cases even executed, in terms of megawatts. A third factor in its favour was the environment.

According to the NIO study entitled Feasibility studies for the extraction of energy from current and haliohydro gravity along Pakistan coast, water flows with high velocity during floods and ebb tides, which was a very favourable requirement for the extraction of energy from the currents. The bays and lagoons along Makran coast west of Karachi have narrow entrances and enclose large sea areas. The salinities in these semi-enclosed areas were higher than the open sea due to the high rate of evaporation. If the narrow entrances of these bays and lagoons were closed artificially, the evaporation will create hydraulic head with higher elevation of water level on the seaside. This head can be utilised for obtaining power. The power resources of the creeks system were great assets for future energy supply in the region. The serious power shortage which the industry was facing at Karachi can be adequately met from these resources, the study said.

Investigations carried out in all the main creeks of Indus Delta, namely Korangi Creek, Phitti Creek, Chan Waddo Creek, Khuddi Creek, Khai Creek, Paitiani Creek, Dabbo Creek, Bhuri Creek, Hajamaro Creek, Khobar Creek, Qalandri Creek, Kahr Creek, Bachiar Creek, Wari Creek and Kajhar Creek showed that, about 900MW can be produced.

In the emerging scenario when developed countries were vying to tap into environment-friendly options of tidal energy, one wonders why it was not was never considered as an option in Pakistan.