NASA JPL has an article on a scheme to generate tidal power using a "hydrokinetic energy system" - Turning the tide to energy.

NASA researchers who developed a new way to power robotic underwater vehicles believe a spin-off technology could help convert ocean energy into electrical energy on a much larger scale. The researchers hope that clean, renewable energy produced from the motion of the ocean and rivers could potentially meet an important part of the world's demand for electricity.

Many different methods already exist for using moving water to create power. Hydroelectric plants, for example, are among the most established and least expensive sources of electricity. They benefit from the large hydrostatic pressure difference between the water surface behind the dam and the turbines that can be harnessed to produce power. But the power that can be produced in this manner is limited, because most of the suitable rivers already have hydroelectric dams.

Other technologies have been designed -- and are being developed -- to turn the energy of ocean currents, tides, and flowing rivers into another kind of power, called hydrokinetic energy. Many of these hydrokinetic energy systems use underwater turbines, similar to those in wind farms. Ocean currents or tides turn the turbines, which generate electricity that can be transferred by cable to shore.

Jack Jones, an engineer at NASA's Jet Propulsion Laboratory, and Yi Chao, a JPL scientist, have designed a new kind of underwater hydrokinetic energy system. It uses water motion to generate a high-pressure liquid rather than electricity. That liquid is then transported to shore and used to produce electricity on land. Caltech, which operates JPL for NASA, holds the patent on this innovative energy technology.

The JPL/Caltech hydrokinetic energy system is a spin-off from a research project to find a new way to power robotic underwater vehicles. Most robotic underwater vehicles run on batteries and have to be recovered by ship to have their batteries recharged or replaced.

In this project, initiated by Pat Beauchamp of JPL's Center for In Situ Exploration and Sample Return, Jones was asked to develop a way to use temperature differences in the ocean to power submersibles. He had previously developed thermally controlled balloons for Venus, Mars and Titan. Jones was teamed up with Chao, who uses underwater gliders in his oceanographic research. "I saw we could extend the lives of these vehicles significantly by harvesting energy from the ocean environment," Chao says.

Jones and Chao designed a system that takes advantages of changes in ocean temperature to create a high-pressure fluid that can be used to generate power. "The trick was to find a special substance known as a phase change material that changes from a solid to a liquid as the temperature in the environment changes from cold to warm," Chao says. "When the material melts, it expands, compressing a central tube in which another liquid is stored. This liquid, now under high pressure, is used to generate electricity to charge the battery underwater."

Working with colleagues from JPL and the Scripps Institution of Oceanography at the University of California at San Diego, and funded by the Office of Naval Research, Jones and Chao are developing a prototype underwater vehicle powered by this new energy system. They will conduct field tests in the Pacific Ocean this fall.

While they were working on this project, the researchers realized that they could employ the same concept -- using an environmental pump to generate a high-pressure liquid -- to produce electricity from the world's ocean.

The Globe and Mail has a report on tidal power in Canada, noting that "Nova Scotia is testing water-driven turbines that could produce 10 per cent of the province's peak load" - Clean power comes in with the tide.

Atlantic Canada's Bay of Fundy has some of the world's highest and most powerful tides. Every day, 100 billion tonnes of seawater surge in and out of the bay - a perfect source of clean, reusable alternative energy, if it can be properly harnessed.

Tidal power isn't new, of course; small grain mills were powered by tides in Europe centuries ago. But tapping into the reliable, natural ebb-and-flow of water to generate electricity didn't begin until the 1960s.

In 1984, Nova Scotia opened a small plant that takes advantage of the massive Fundy tide as it rushes up the Annapolis River, funnelling the surge through turbines to generate power. That Annapolis plant produces about 20 megawatts a day, enough to power about 4,000 homes.

Now Nova Scotia is preparing for a much bigger Fundy project, one that is unique to North America and could eventually produce 100 MW of electricity, about 10 per cent of the province's peak load.

The $50-million pilot project, set to begin by next fall or the spring of 2010, will be different from previous tidal efforts not only in size but also in method.

Rather than pushing water through turbines in the "barrage" style of a hydroelectric dam, three experimental turbines will be dropped into the deep waters of the bay and will operate more like underwater windmills.

"If it's done the way we think it could be done, residents of Nova Scotia wouldn't know that the tidal farm existed," says James Taylor, general manager of environmental planning and monitoring at Nova Scotia Power Inc. in Halifax.

The provincial government has chosen three companies to take part in what's called the Fundy Institute of Tidal Energy. The project will test three turbines for at least two years and feed about four MW to the province's electrical grid for immediate use - something other trial projects don't do.

A project at Race Rocks off Vancouver Island, for example, charges storage batteries but the power isn't used commercially.

"Most projects to date have just been burning off energy," says John Woods, vice-president of energy development at Minas Basin Pulp and Power Co. Ltd. of Hantsport, N.S., which will manage the Fundy project.

The test site will be in the Minas Passage, just west of Black Rock. The first challenge will be to put the massive turbines in the water; then underwater cables six-to-eight inches in diameter will be run about three kilometres to shore, where a small facility will feed the turbines' energy to the power grid.

"Pruned" has a post on an OTEC based "energy island" concept - OTEC Steading.

It looks more sleek and futuristic (or retro-futuristic, if you're much versed in vintage SF) than other prototypes, a creature more adapted to fictional outer space than to the oceans.

But something about its bulbous main compartment led us to wonder if there is enough room inside for seasteaders to muck about with nation-building. Amidst all those noisy condensers and turbine generators and navigational gears, perhaps even inspired by them, they try to formulate the mechanics of a new micro-civilization, new identities and new cultural traditions.

If not, how about a second, similarly bulbous habitat module perched on top, above the water line? Or a polyhedral honeycomb of spherical units for, you guessed it, climate change refugees to call home? It would be a kind of artificial energy island but sovereign.

With an overabundance of low-cost, carbon-neutral energy, this New Tuvulu could desalinate fresh water for its citizens and a mini-aquaponics industry. Power enough open-ocean aquaculture cages, and all will be well fed. Any surplus electricity, fish and fresh water would then be traded to neighboring countries. Consequently, their GDP skyrockets.

Business Green has a report on the latest example of the trend towards clean energy powered data centres - Morgan Stanley eyes up tidal-powered datacentre.

A group of investors, including investment bank Morgan Stanley, are set to fund a £250m off-grid tidal-powered datacentre in the north of Scotland, it was confirmed yesterday. The banking giant said it is to work with tidal power company Atlantic Resources Corporation – in which it holds a stake – to build the site by 2011.

The datacentre would require about 150Mw hours of power and the alliance wants this energy to be sourced entirely from tidal arrays.

The zero-carbon datacentre will seek to tap into increasing demand for greener IT systems and be opened up to third-party companies to hire space. " They will be looking for tenants for the datacentre," said a spokesman for the partnership.

The scheme must still secure planning permission to go ahead, and although the Scottish government has recently signalled its support for marine energy projects, only one commercial-scale tidal energy project has so far gone into operation in the UK – and that took 13 years to come to fruition.

However, the Morgan Stanley project is expected to avoid one of the main technical challenges faced by tidal energy projects, by connecting direct to the datacentre facility and not linking to the national grid.

The project is the latest in a series of innovative proposals designed to tackle datacentres' increasing energy use and associated carbon emissions. Globally, datacentres are responsible for the same amount of emissions as an average European country, according to research by Gartner – accounting for about a quarter of the 580 million tonnes used by IT equipment worldwide.

The Department of Energy and Climate Change estimates server farms are responsible for three per cent of electricity use in the UK, a figure expected to double by 2020.

Consequently, growing numbers of firms are investigating ways to power da tacentres using renewable energy. Earlier this year, submarine cable operator Farice signed a £12m deal with networking company Thus for a high-bandwidth internet connection between UK businesses and datacentres in Iceland that could be powered using emission-free geothermal energy.

TreeHugger has a post on a raft of Danish wave power experimental projects - Three Wacky Danish Wave Power Projects.

Portugal gets the distinction of having both the world's first commercial wave power plant, Aguçadoura Wave Park, which officially opened last month and is expected to grow to 21 MW of capacity - it currently has 2.25 MW of capacity or about enough to power 1,500 homes.

But the Danes, who pride themselves on being leaders in both using wind energy (more than 20 percent of their electricity is wind-generated) and in wind technologies, are trying to catch up with some wave energy (and even a unique combined wave-wind energy project). Currently the Danes have 12 "active" wave power projects. Hit the jump to see the Wave Dragon, Poseidon's Organ and the Wave Star.

1. Wave Dragon

The Wave Dragon, which looks like an extended ski jump ramp, is a wave power demonstration project on 1/4 the scale the developers eventually hope to achieve. Wave Dragon uses a hydro power concept: wave "reflectors" direct waves toward a ramp, behind which is a reservoir that stores the water until it is flowed over hydro turbines. The test site in Danish waters has been running for 20,000 hours - a 7 MW project is now planned off the coast of Wales. Because of the Portuguese government's proactive stance on wave power, a 50 MW project is planned there as well.

2. Poseidon's Organ

Since the spring of 2007, this 37-meter long wave power transformer (sans the turbines) has been under construction at Lolland in Southern Denmark, close to shore. It launched in August 2008. Floating Power Plant is now trying to get investors for a 230-meter-long platform that in addition to the oscillating water columns producing wave energy would also support three wind turbines, together to make enough electricity to support 12,500 households annually. Amazingly, Floating Power Plant is also hoping to put the first platform at a location in Portugal.

3. Wave Star

Though Wave Star is the hardest of the three to visualize, it may hold the most promise. A Wave Star platform cuts at a right angle into the wave motion, with floats partially submerged in the water. When a wave rolls in, the floats are lifted up one by one until the wave subsides. The rising float drives a piston which in turn powers a hydraulic motor connected to a generator. Wave Star's inventors believes this wave solution will be comparable in price to wind turbines and entail less materials use. Wave Star's prototype is installed on Denmark's northwest coast and has over 6,000 hours of operation - the next step is a 3 MW model.

Greentech Media has released a report on the future of ocean power, identifying 81 projects underway - Trawling for $500 million in ocean power

The emerging ocean power industry is poised to grow from less than 10 megawatts of capacity worldwide today to more than 1 gigawatt in six years, reaching a market worth more than $500 million annually, according to a report by Greentech Media and the Prometheus Institute scheduled for publication next week.

The report, "Forecasting the Future of Ocean Power," offers a comprehensive look at the technologies, players and market outlook for an industry that is currently dominated by developments in the United Kingdom, the United States, Canada, Norway, Ireland and Australia.

In six years, more than $2 billion will be invested to build commercial ocean wave power farms and another $2 billion will go towards research and development globally, said report co-authors Daniel Englander and Travis Bradford. Englander is a Greentech Media analyst while Bradford is the president of the Prometheus Institute.

The concept of using waves and tides to generate electrical power isn't new. The first patent for an ocean power device was filed in France in the 18th century, while wave motor designs were pursued in the California during the 19th and 20th centuries. However, researchers and entrepreneurs truly dived into the field in the mid-1970s and early 1980s, when the oil crisis spurred some renewable energy developments.

The current push for clean energy has renewed interest in ocean power projects, and most of the current designs originated in the late 1990s and early 2000s.

The industry's 35 most active companies have received just over $500 million in investments since 2001, the report said. The money has come from a variety of sources, including venture capital, loans and certain types of government funding.

Only a handful of companies have reported revenues, however. And the industry faces tough challenges in engineering, installing and operating equipment that can generate power at attractive prices.

Ocean energy resources are abundant and reliable, while the size and energy content of waves can be predicted from three to five days in advance. The currents and tides, in fact, are 832 times denser than the air that drives wind turbines.

The ocean power industry has another key advantage that other renewable energy sectors don't have. It can shorten the time needed for research and development by re-engineering proven technologies from the offshore oil and gas, wind power and shipbuilding industries.

"Technology transfer between traditional marine and wind industries and the ocean power industry has allowed many companies to move rapidly into advanced research and development," wrote Englander and Bradford. "As such, the development bottleneck in ocean power often occurs in the scaling-up stage and not the device design stage."

The United Kingdom, the United States, Australia and Ireland are among the top ocean power project developers in the world, according to the International Energy Association. In 2006, the association identified 81 projects – from university and government-led research to private industry initiatives

Four times a day, without fail, New York City's East River will change directions. It's been doing that for ages and will continue to do so long after we are gone. The tides are a constant, powerful force, and the folks at Verdant Power are on Roosevelt Island experimenting with a way to draw energy from them without impeding their flow or harming the local wildlife.

The Roosevelt Island Tidal Energy Project gives Verdant Power the rare opportunity to test turbines that were developed by Dean Corren, their director of technology. Submerged beneath the surface of the river, these turbines turn passively to face the tides the same way a weather vane would. What makes these turbines special is that unlike dams and barrages, they will employ a kinetic hydropower method will have little to no effect on the local ecosystem.

So far, the tests have been very promising. They are drawing power successfully, and in the two years they have been monitoring the project, there has been no evidence of any harm to local fish or birds. While the flow of the tides are strongest and the turbines are getting the bulk of their work done, the fish aren't even around. They prefer to save their energy for when the tide is weaker. Of course, during that time, the turbines are not turning. Also, the fish there tend to spend their time near the banks of the river, and the turbines are in the depths near the center. In fact, Verdant Power has gathered so much new data about local fish and bird populations that biologists have benefited from the project.

The New York Times has a report on new funding for work on OTEC by Lockheed Martin (better than paying them to build weapons, says I) - Lockheed Set to Tap Ocean Thermal Energy With DOE Funds (via OTEC News).

The world’s oceans are an energetic place, and military-industrial giant Lockheed Martin said today it has been granted $1.2 million by the Department of Energy to demonstrate that ocean thermal energy conversion is possible. Although the ocean often doesn’t feel very warm, the temperature gradient between the warm, sun-soaked surface and the frigid, dark depths provides enough of a differential to run a heat engine. The idea has been kicking around for over a century but has never been scaled. Lockheed Martin helped build the largest ocean thermal energy conversion system to date back in the 80s, but it only ever produced 50,000 watts, or .05 megawatts.

For those who aren’t so up on their thermodynamics, whenever you have a temperature gradient, there is accessible energy to be had. Ocean thermal energy conversion (OTEC) works best when there’s a temperature difference of at least 20 degrees Celsius. Waters of two different temperatures are pumped through a heat exchanger which vaporizes and then condenses the water, producing energetic steam in the process.

Lockheed will work on the problem of getting that cold, deep water up to the surface. The small-scale OTEC system Lockheed had previously help design in Hawaii used a polyethylene pipe that was 2,150 feet long and 2 feet in diameter to draw up cold water. Under terms of the grant, Lockheed will demonstrate cold water pipe fabrication using modern fiberglass and low-cost composite material manufacturing methods.

Harnessing ocean thermal energy is likely farther out than both wave and tidal energy systems. But if scaled, it could provide consistent base-load energy and help tropical islands, like Hawaii, attain energy independence, a serious issue in a world of petropolitics.

Bloomberg reports that Scotland is proposing large financial incentives for tidal power generators - Scottish Power to Spend $184 Million on Tidal Power. More at the FT.

Scottish Power Ltd., Iberdrola SA's U.K. unit, plans to invest more than 100 million pounds ($184 million) in tidal power as the utility develops energy production that doesn't add to carbon-dioxide emissions.

Scottish Power is studying two sites in Scotland and another in Northern Ireland for deploying underwater turbines capable of generating a combined 60 megawatts of electricity, enough for more than 40,000 homes, the Glasgow-based company said today in a statement. It will install as many as 20, 1- megawatt turbines at each site, following a year of testing.

Europe's utilities are racing to develop new forms of energy production to harness natural sources of energy, including the wind, waves and solar rays. The technologies are more costly than conventional power production, and are subsidized by governments. They don't emit carbon dioxide, and avoid emission-permit costs.

The planned turbines use the Lanstroem technology that has undergone four years of testing in Norway, developed by Hammerfest Stroem AS, a company owned by Scottish Power, StatoilHydro ASA and Hammerfest Energi. Planning applications may be made in summer next year, and generation may start from 2011.

Just one of the sites, the Pentland Firth, may have potential tidal energy to meet one-third of Scotland's power requirements, the company said. The area includes the stretch of sea between the Orkney Isles and mainland Scotland.

The Crown Estate, which owns rights to the resources of the U.K. continental shelf, said it's seeking expressions of interest for use of the Pentland Firth and plans to allow more than 700 megawatts of power-generation capacity to be built there by 2020. There may also be opportunities for demonstration sites elsewhere, it said in a presentation on its Web site today.

I like to think I'm pretty bullish about the potential of ocean energy, but the guys at Carnegie Corp are thinking a lot bigger than I am, claiming that Australia has a resource base of 171 GW of wave power and that it could provide 35% of our power needs in this report from the SMH - Nation could be powered by waves: report.

Clean power developer Carnegie Corporation says more than a third of Australia's base-load power needs could be economically generated by wave technology, according to a report commissioned by the company.

The report, compiled by RPS MetOcean, says that Australia has a potential near-shore wave energy resource of about 171,000 megawatts (MW) - four times the country's total installed power generation capacity, Carnegie said.

"This report further supports Carnegie's view that Australia has the world's best wave energy resource - a resource we hope will be utilised through technologies such as CETO for base-load power generation," managing director Michael Ottaviano said in a statement.

CETO technology uses submerged units anchored to the sea floor that move with the motion of passing waves, driving the pumps which in turn pressurise seawater that is delivered ashore through a pipeline. The high-pressure seawater is used to drive hydroelectric turbines and generate base-load electricity.

Carnegie said a "conservative" ten per cent of Australia's calculated near-shore wave resource is estimated to be economically extractable. This means that around 35 per cent of Australia's current power usage could be met by harnessing wave energy, the company said.

There seems to be plenty of ocean power news out this week. Scientific American leads off with a report on some new technology in Scotland - The Tide Is Turning: Turbine Rides Underwater Currents Like a Kite.

There is no market yet for turbines that turn the tides into a source of energy from deep beneath the sea. But that has not stopped mechanical engineers at the University of Strathclyde's Energy Systems Research Unit (ESRU) in Scotland from developing one that will ride the tide while latched to the seabed by a cable—like a kite flying on a windy day.

The ESRU team's goal: create a device that literally goes with the flow rather than resting on the sea bottom like an underwater windmill—a model already being developed by a handful of companies. The kite and cable model is designed to facilitate placing tidal turbines in deep water, where the stronger current has the potential for providing greater power but also makes it extremely difficult to plant a turbine in the seabed.

"The problem with regular turbines is the bigger they get, the harder they work, and the more likely the force of the water is to damage the turbine," says Andrew Grant, an ESRU mechanical engineer. "Our turbine can fly like a kite in the water." Instead of planting the base of a turbine in the seabed, researchers need only plant an anchor for the tether.

Another key difference in ESRU's design is that the turbine has two rotors attached—one in front of the other that turn in opposite directions on a single axis. The rotors' blades are made of either solid aluminum alloy or glass-reinforced plastic, depending on their sizes. By having the rotors turn in opposite directions, Grant and his team are trying to cut down on reactive torque (which pushes the turbine in the opposite direction) so that the unit can be attached to a relatively simple mooring system even in very deep water.

This "contra-rotating" design has been tested on wind farms since the 1980s but did not provide an advantage (in terms of generating more energy with less wind) in the open air, Grant says. ...

Lunar Energy, a U.K. tidal power company, in March began working with Korean Midland Power Company to create a giant 300-turbine field in the Wando Hoenggan Waterway off the South Korean coast. The plant is expected to provide 300 megawatts of renewable energy to Korean Midland Power by December 2015. Utilities interested in tapping into tidal power will have to spend money to create the energy-delivery infrastructure, or at least convince government to pay for it. One thing working in favor of new energy sources: the cost of oil is not getting any cheaper.

Tidal power technology developer Pulse Tidal have said its hydrofoil device could be operational next month in the Humber Estuary. The Sheffield company has installed piles ready for the main structure of the system to be put in place this week in water depths of about five metres.

The Pulse system is designed to generate power from tidal currents in shallower waters than tidal systems that use rotors to drive turbines. It uses two 12 metre long hydrofoils - which are like large underwater aeroplane wings that rise and fall in a tidal current to generate power.

The 100kW test system is to be connected to the grid at the Millennium Inorganic Chemicals plant on the south bank of the Humber.

Howard Nimmo, executive director at Pulse Tidal, was speaking at the Renewable Energy Association's annual Wave and Tidal Technology Symposium in Cardiff on Tuesday. He said: "The main structure is going to go offshore later this week. We hope to have the machine operational some time this October, so it's quite an exciting time." ...

In the location of the current Beatrice Offshore Wind Farm, the wind turbines can produce 5MW, but in the 45 sea depths a subsea rotor system could produce just 1.5MW - or 3MW from a twin-rotor system, he said. The Pulse system in similar depths could generate more than 5MW, Mr Nimmo claimed.

"For Pulse, the length of the foils are not dependent on depth, we can get a long and big swept area, which gives us an advantage against that key development barrier," Mr Nimmo said.

While the system being installed at the moment will generate only enough power for the equivalent of 70 households, the Pulse director said the company is already working on a 1.5MW demonstration project, and has hopes of scaling up to a 5MW system.

The company is aiming to develop oscillating hydrofoil columns that could stretch across a tidal stream.

New Energy Focus reports that Pelamis has inaugurated a 2.25 MW wave power plant in Portugal - Inauguration for world's first commercial wave farm.

Scottish wave power firm Pelamis is holding an inauguration ceremony today in Portugal for what is being described as the world's first commercial wave power farm. One Pelamis machine is in position 5km off the north Portuguese coast, but three of the "sea snake" machines have been assembled in Portugal with one now being towed out to sea and a further machine currently in port.

Yesterday saw the company's project development engineer revealing to the annual wave and tidal power industry Symposium that the Portguese project had run into some delay because of faulty buoyancy units on the cables transferring power ashore.

But, Andrew Scott said the company is now back on track attempting to get three of the 750kW P-1A machines up and running. Mr Scott said: "In the next few weeks we are trying to get all three machines online simultaneously, and we will be gradually pushing the envelopes of the machines."

Phase two of the project will see Pelamis Wave Power developing a 20MW array of its machines in Portugal, where to reach its European targets to generate 31% of energy from renewable sources by 2020 it will need 60% of its electricity to come from renewables.

Pelamis - named after a surface-swimming sea snake - involves a long snake-like machine that is partially submerged in the sea with three jointed compartments that rise and fall as waves pass along it. The movement of the joints drives three hydraulic rams that generate power. The 2.25MW Portuguese wave farm is being developed for the power company Enersis and Babcock & Brown, connected up to a substation at Aguçadoura. The machines were fabricated on the Isle of Lewis in Scotland and will be controlled from the Pelamis headquarters at Leith, Edinburgh.

The Washington Post has an article on the latest iteration of Verdant Power's attempts to harness the tidal power of New York's East river - N.Y. Tests Turbines to Produce Power .

On a recent morning, a crane sank a 16-foot rotor into the waters of the East River and divers swam deep to bolt it to the bottom. By early evening, as the northerly current sped up, the rotor began to spin, a big thunk sounded in the control room, a green light went on, and electricity began to pour into a nearby supermarket.

The scene represents an experiment in tidal power, using turbines that look like underwater windmills, and it is the first of its kind nationwide and one of only a few such pilot projects in the world.

"This is just the beginning of a project, but the project itself is emblematic of a whole new industry," said Trey Taylor, the president of Verdant Power, a small company that created the experiment and hopes to expand it to commercial use with 300 turbines in the East River that could power up to 10,000 homes in the city.

Engineers, policymakers and energy experts say projects like the East River tidal turbines are already placing this city at the urban vanguard of energy production. They say New York City is uniquely positioned to advance sustainable energy projects because of the city's enormous need for power, its high electricity costs, and the pressure for new sources created by its unusual rule that 80 percent of energy must be generated within the city.

Mayor Michael R. Bloomberg has sought to make New York the cleanest and greenest major city in the country. He has faced setbacks -- for example, when his congestion pricing plan to reduce the number of cars in Manhattan was killed by the state legislature. He was mocked when he spoke of placing windmills on bridges and skyscrapers, and a few New York tabloids ran illustrations of wind turbines on the Brooklyn Bridge and the Empire State Building.

Still, he has asked private companies to submit ideas to develop wind, solar and water energy projects. And for the past year, his administration has supported the water turbines, a project many years in the making.

The idea is simple: As water flows, it spins the rotors and produces electricity. The turbines run according to the tide charts, which are as predictable as phases of the moon. The idea was rejected for state funding in 2000, only to be accepted a few years later.

The strength of the flows of the East River -- which is technically not a river, but a tidal strait, whose current switches direction throughout the day -- makes it an ideal spot for generating power. The strength of the current also makes it hard on equipment. Swift-moving waters chewed up the first two types of turbines, which Verdant, a small, private company, installed in late 2006 and early 2007.

The first blades were fiberglass with a steel skeleton. Later, another set of rotors was made from aluminum and magnesium. "The water was very powerful, so it broke the rotors," Taylor said.

The newest blades are made from an aluminum alloy, attached to rotors whose strength has been extensively tested. If all holds together, Taylor expects to apply for permission to expand and launch a commercial operation.

Ocean power seems to be appearing in the news with great regularity in recent weeks - the latest story I noticed was in The Guardian, looking at a new turbine design from Oxford that is cheaper and more efficient than earlier designs - Second generation tidal turbines promise cheaper power.

Harnessing the vast energy of the UK's coastal tides could become much simpler and cheaper with a new design for the next generation of underwater turbines. The device, unveiled by a team of engineers from Oxford University, re-thinks the way power is generated underwater and the inventors believe it will be more robust, more efficient and cheaper to build and maintain than anything in operation today.

There is an immense potential resource of clean energy from the tidal flows around the UK: conservative estimates suggest there is at least five gigawatts of power, but there could be as much as 15GW, equivalent to 15 million average family homes. Tidal generators can harvest the energy of these moving streams, with the added advantage that the resource is, unlike wind, predictable.

There are only a few underwater turbines in operation today and they all operate like underwater windmills, with their blades turning at right angles to the flow of the water. In contrast, the Oxford team's device is built around a cylindrical rotor, which rolls around its long axis as the tide ebbs and flows. As a result, it can use more of the incoming water than a standard underwater windmill.

At full size, a Transverse Horizontal Axis Water Turbine (Thawt) rotor would be 10m in diameter and 60m long. Connecting two of these together with a generator in the middle could produce around 12MW of power, enough for 12,000 average family homes.

"To do that, you only need three foundations and one generator," said Martin Oldfield, senior research fellow of engineering science at Oxford University. "To do that with a [windmill] would require five foundations and 10 generators."

The Thawt device is mechanically far less complicated than anything available today, meaning it would cost less to build and maintain. "The manufacturing costs are about 60% lower, the maintenance costs are about 40% lower," said Malcolm McCulloch, head of the electrical power group at Oxford's engineering department.

Underwater turbines that harvest tidal currents have already become an established technology in the world of clean energy. So in order to push the frontier further, a group of engineers at Oxford have been tinkering away on a design that promises to be even more powerful and efficient. The group recently introduced an innovative Transverse Horizontal Axis Water Turbine that will not only collect more energy but require 60% lower manufacturing costs and 40% lower maintenance costs.

I mentioned ocean energy company Atlantis recently, who are doing some trials in Victoria's Corio Bay - both the Geelong Advertiser and The Age have reports on developments.

A SINGAPORE-BASED company is set to install two tidal turbines in The Rip off Queenscliff in a world first. The Solon turbine, a deep-water turbine suitable for installation in fast flowing currents, has not been installed anywhere in the world. It has the potential to power about 1000 houses.

Atlantis Power Resources has been testing the unit in Corio Bay and initial tests have proved successful. Chief executive officer Tim Cornelius said the company had spent two years developing the top secret project and had begun talks with authorities on applying for a permit. "Queenscliff has an excellent concentration of tidal flow so it is an ideal spot," he said.

When placed in ocean and river currents, the turbine transforms the kinetic energy from the moving water, and converts it into commercial quantities of AC or DC electricity. The power can then be fed directly into the grid.

The "tidal farms" have a 20-year life span and if approved, can be installed and operational within 30 days.

WITH Europe aiming to generate a fifth of its energy from renewable technologies by 2020, and the UK hoping to contribute a tenfold increase in energy it generates this way, to 15 per cent, a green vision has been set for the next decade.
The government is consulting industry and planners, and the Renewable Energy Strategy (RES), due for publication next year, will set out the route-map for this green transformation.

There are three energy types to consider – electricity, heat and transport – each with different technologies and demand. For example, renewable electricity is relatively established, but, renewable heat and transport has almost no installed capacity.

To meet our 15 per cent target, we need to ensure each sector grows considerably. The RES suggests increases of 32 per cent of electricity (from less than 5 per cent today), 14 per cent in heat (1 per cent today) and 10 per cent transport (under 1 per cent today)If we do not meet one sector target, we will need to exceed in another, or trade carbon with other countries.

"Whilst we were burning North Sea oil, Germany were building the wind turbines, and Scandinavian countries were building biofuel wood burners," explains Jason Ormiston, the chief executive of trade association Scottish Renewables,

But he is positive about Scottish renewables industries: "With the certainty of renewable energy targets in the RES, businesses will plan the finance, resources, and production they need," he says.

"This will be good news for Scotland, which is a leader in manufacturing wave and tidal technologies, and offshore engineering. Based on the evidence of the government's support of wind-generated electricity, I believe we could transform the way we generate heat and power transport."

Finance Asia has a report on Asian tidal / ocean current power company Atlantis - Tidal power company moves to the next level.

Atlantis Resources, a developer and manufacturer of electricity-generating tidal current turbines, has moved a step closer to a commercial-scale deployment of its technology with the acquisition of Current Resources, an energy origination and project development business owned by Morgan Stanley. ...

Power generation using tidal currents is the latest renewable energy source to emerge as a viable alternative to fossil fuels. The technology has yet to be deployed commercially, but the unparalleled predictability of the movement and intensity of tides suggests it has clear advantages for the power industry, versus some of the other renewable energy sources such as wind or solar power.

According to an Atlantis press release, ocean power, which includes tidal current power, wave power and ocean thermal energy conversion, represents a vast source of energy estimated at between 2,000 and 4,000 terawatt hours per year. The US and the UK combined have sufficient ocean power potential to meet around 15% of their power needs.

Having spent 10 years developing its turbines, Cornelius says Atlantis is now ready to become the first tidal power developer to establish mini-arrays (essentially farms or fields of multiple subsea turbines of 1 or 2 megawatts each). This will allow it to aggregate the necessary data about environmental and turbine performance before it moves on to apply for permits for projects of a much more significant scale.

“We are entering into an exciting phase where we will focus on the necessary steps to build up to meaningful commercial quantities of tidal generation projects,” he says. “The first step will be to deploy lots of between 5 and 10 turbines to allow governments and the regulators to get comfortable with the technology and the performance before we apply to scale-up. We hope to start deploying turbines by June next year, and building up to 2011 when we plan to enter the commercial side of deployment with projects that have a capacity of 150-500MW.”

These commercial projects should see the company turn cash flow positive in 2011, he adds.

The company has had a 150KW turbine installed and connected to the grid in Australia since 2006 and is hoping to build up its generation capacity there, but it is also actively looking for several other sites both in Asia and Europe where it can set up trail arrays. It is currently evaluating potential installation opportunities in the Pentland Firth off Northern Scotland, in the Bay of Fundy and in British Columbia off the east and west costs of North America and off the coast of South Korea.

China also has the potential to become a “huge” market, according to Cornelius, since the company’s Nereus turbine that is suitable for shallow-water can be deployed not just in tidal oceans, but in rivers too – and that is a resource that China has a plenty of. Atlantis also has a second type of turbine, the Solon, which is a deep-water turbine that can be installed in some of the fastest flowing currents in the world.

“China will be a key market. South Korea has some of the best tidal resources in the world, Japan has tidal resources as well and the Philippines has fantastic tidal flow. So, Asia is a hugely exciting place for us, because there is so much resource and so much need for clean power.”

CNet's GreenTech blog is speculating that Google may be thinking about build floating data centre's one day - Google files patent for wave-powered floating data center. Fans of Neal Stephenson's book Cryptonomicon will no doubt recognise the potential for the creation of offshore data havens - or perhaps more than just data.

Google sees the future of computing at sea.

The search giant has filed a patent for a "floating data center" that uses wave motion to power on-board computers and the ocean's water to cool them.

The patent was submitted in February last year but was spotted in the U.S. Patent & Trademark office's electronic filings and posted at Slashdot on Saturday.

The system Google engineers sketch out is a self-powered data center placed three to seven miles offshore, potentially operating off the grid. Standard shipping containers would house racks of computers that could be transported by truck and placed onto a boat by crane.

A wave-power generator would be the primary source of electricity. But wind turbines could be used to, for example, run water pumps and a tidal power generator could be used in rivers.

The patent specifies the use of a so-called Pelamis machine, which uses pontoons with pumps to convert wave motion into electricity. A British company, Pelamis Wave Power, is operating a prototype in Scotland and intends to install one off Portugal.

Google engineers calculate that an array of pontoons spread over a square kilometer (a bit more than a half mile) could produce 30 megawatts of electricity, enough to operate a single system.

Also envisioned is equipment to use the direct current electricity to run DC-capable computers, which some people consider more energy-efficient than using alternating current.

The WSJ (Winston Salem Journal, that is) has an article on tidal power in Maine - Tidal Power: Project advances goal of tapping ocean's energy.

Workers spent the past winter tinkering with high-tech turbines slung beneath a barge in the cold waters off the Maine coast before getting them to produce a modest 20 kilowatts, enough electricity to power a half-dozen homes.

Far from discouraged, Ocean Renewable Power Co. is spending the summer preparing to deploy larger turbines capable of producing up to 5 megawatts. Or, enough electricity to power 5,000 houses.

Eventually, the company envisions producing enough electricity to power 22,000 homes by harnessing the power of Passamaquoddy Bay, where twice each day the tide rises and falls upward of 20 feet, the greatest tide change in the continental United States.

"This is our beachhead opportunity to enter the market," John Ferland, the project manager, said.

Even before energy prices surged, a study conducted by the electric-utility industry concluded that tidal power could be produced at a cost competitive with wind power and power plants fired by natural gas.

Companies raced to file permits with the Federal Energy Regulation Commission, but Ocean Renewable Power has moved a step forward by using its turbine-generating unit to produce power. It is one of dozens of developers positioning for a lead role in tidal-power technology.

"Basically, the technology is here. It's just a matter of engineering it for the lowest cost, the highest reliability and the longest survivability in a hostile and corrosive environment," said Roger Bedard, who led the study for the Electric Power Research Institute in Palo Alto, Calif.

The experiment taking place in the 120-foot-deep Western Passage represents the latest advance in an emerging technology that seems to be moving forward in baby steps but could one day help meet the growing worldwide demand for electricity.

Ocean Renewable Power was the only developer with turbines in U.S. waters that generated electricity this year, Bedard said. He said that tests are also being run elsewhere, including the British Isles, Canada and Italy.

As the nation seeks to wean itself from foreign oil and curb global warming, alternative-energy sources such as wind, solar and geothermal are becoming more attractive.

Tides hold a number of advantages. Winds can turn calm and clouds can obscure the sun, but the immutable tides turn twice a day no matter what, providing a steady and predictable source of power. Because of water's greater density, the technology requires fewer turbines to produce the same amount of electricity as wind. And underwater turbines are unlikely to draw complaints about spoiled views or disrupted tranquility from coastal residents.

This looks like a variation on the "energy island' theme - a Japanese proposal to build "eco rigs" to generate both power and food - Massive floating generators, or 'eco-rigs', to provide power and food to Japan. How practical the idea is remains to be seen.

Battered by soaring energy costs and aghast at dwindling fish stocks, Japanese scientists think they have found the answer: filling the seas with giant “eco-rigs” as powerful as nuclear power stations.

The project, which could result in village-sized platforms peppering the Japanese coastline within a decade, reflects a growing panic in the country over how it will meet its future resource needs.

The floating eco-rig generators which measure 1.2 miles by 0.5 miles (2km by 800m) are intended to harness the energy of the Sun and wind. They are each expected to produce about 300 megawatt hours of power.

Some energy would be lost moving the electricity back onshore, but when three units are strapped together, scientists at Kyushu University say, the effect will be the same as a standard nuclear power station.

The eco-rigs' gift to the environment does not stop there: some of the power that the solar cells and wind turbines produce will be hived off to fuel colossal underwater banks of light-emitting diodes (LEDs).

The lamps are intended to convert the platforms into nurseries for specially selected seaweed that absorbs carbon dioxide and feeds fish and plankton. Deep-sea water that is rich in minerals will enhance the seaweed growth. The wind turbines will power pumps that will then draw the water to the surface.The rigs will be unmanned and comprise several hexagonal platforms.

Strapped between them will be large nets designed to support the weight of wind turbines and about 200,000 hexagonal photovoltaic generators — super-efficient solar panels that are about the size of a double bed. The LEDs will shine down from the panels.

As a country with virtually no fossil fuels, price rises in oil and gas have chilled the corporate sector and the Japanese Government.

The Times has a report on the slow pace of development of wave power in the UK - Wave power all at sea until tide turns.

Jim Mather, the energy minister, has described marine power as “the heart of our ambitions to develop a vibrant renewables sector”. John Griffiths, a non-executive director of the Orkney centre, is clear where blame lies. “In 1999 everybody was saying that come 2005 we should be moving towards a range of commercial tidal and wave devices. That time has gone and among the things that have held up progress has been a huge emphasis on wind. Some of the inertia has been evident from Westminster compared to the Scottish government. There is a dearth of funding in wave and tidal power.” ...

Orkney is to test a number of projects, such as Ocean Power Technology’s PowerBuoy system. Another, OpenHydro’s tidal turbine, was connected to the national grid last May, generating electricity to power up to 100 homes. But progress is slow when financial support is muted.

“The sea is a harsh environment,” says Peter Fraenkel, technical director of Marine Current Turbines, which installed a device in Northern Ireland’s Strangford Lough. Looking like an upside down windmill, the structure has the potential to generate electricity to power 1,140 homes. “The sheer force of fast moving water is horrendous,” says Fraenkel. “It takes modern engineering capabilities to come up with solutions. Marine power subsidies are not as generous as they should be.”

Some say Britain is making the same mistakes as in the early years of wind power. “We don’t have a wind industry because in the early days of wind turbine development it wasn’t taken seriously by government,” says Fraenkel. We did not invest in the technology, allowing Danish and German firms to develop it. Now they are making money across the globe.

Tide and wave power will need government help to become commercially viable. Otherwise they too could be developed abroad, and we will miss the chance of a lucrative industry offering highly skilled engineering and manufacturing jobs.

A man particularly aware of Britain’s neglect of renewables is Professor Stephen Salter, generally regarded as the pioneer of wave power. He invented a device in the 1970s called Salter’s Edinburgh Duck, which could extract 90% of energy from waves. But the UK government withdrew funding from wave power in 1982, many believe because of the influence of the nuclear industry. ...

Salter wrote an energy review document for the SNP two years ago that suggested previous calculations of the energy potential of the Pentland Firth, the deep body of water that separates the Orkney Islands from Caithness and is renowned for the strength of its tides, were underestimated.

He believes that if turbines can be designed to work on the bottom of the sea bed, 70m down, and be placed close together, up to 20GW of energy could be extracted from the firth.

Yet having spent 35 years in the field, he, too, is dismayed by the lack of drive from Westminster. “Marine power should be getting a different flavour of subsidies because the wind people are now building in such quantity they are getting their price reduction,” he says. “If we just go on the way we are, nobody will do anything except wind. I think there are still people around who don’t want it to work and who want to go to nuclear.”

Britain boasts almost half of Europe’s tidal stream sites — where the underwater currents can be used to drive turbines — and 47% of Europe’s wave resource. ...

"Wave and tidal power ... could be key for sustainable UK electricity generation in the long term, and provide huge commercial opportunities. We want to lead the way, and that’s why we are undertaking a feasibility study on whether to support a barrage or another project to exploit the tidal power of the Severn estuary,” [Des Browne] said.

Griffiths is less convinced. “The government put into research and development for nuclear something like half a billion a year, for about 17 years,” he says. “If they had put 10% of that [into wave and tidal power] every year since 1999, the marine power situation would look different.”

EE Times has an update on efforts to harness the power of the Gulf Stream - Going deep: Ocean to power grid, recharge fuel cells.

Harnessing ocean power to generate electricity, hydrogen to fuel cars and heat exchangers to cool buildings is the aim of a $13.75 million effort at Florida Atlantic University's Center for Ocean Energy Technology.

The Center has already built a fleet of acoustic doppler current-profiler platforms to be anchored later this year off Florida's Atlantic coast. By 2009, the Center hopes to have permanent mooring sites picked for underwater adaptations of wind turbines. The ocean turbines would be mated to on-shore hydrogen storage facilities that could recharge fuel cells and generate electricity. The moorings will also house pumping facilities to pipe frigid deep ocean water coming from the Arctic Circle into buildings' heat exchangers for cooling.

"The Gulf Stream works 365 days a year, allowing electricity generated from its current to be available 24/7, compared with solar or wind resources. Plus there is a the possibility of using the thermal difference between the warm waters nearer the surface, and the very cold water at the bottom which comes from the Arctic Circle," said Sue Skemp, COET's executive director. ...

The project will also seek to harvest chilly waters at the bottom of the Gulf Stream, similar to a project already underway in Hawaii, Skemp said. Electrical generators in Hawaii currently harness geothermal gradients inside lava tubes. Researchers there also have experience piping cold water ashore from the ocean depths for use in heat exchangers used to cool buildings.

The first Florida project starting later this summer, will establish temporary moorings 13 to 15 miles offshore for acoustic doppler current-profilers used to evaluate how much the Gulf Stream wanders. The fleet of acoustic sensors will evaluate specific sites for energy-generation potential, as well as to catalog the local ecology and evaluate the environmental impact of an underwater power plant.