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In the Land of the Loch Ness Monster, "Sea Snake" Prepares to Ride the Waves

A new device is designed so that when it's hit by big waves, it writhes snake-like in the water and produces electricity



Pelamis Wave Power

EDINBURGH, Scotland -- Pelamis platurus, otherwise known as the Yellowbelly Sea Snake, has a new mechanical namesake, a flexible 180-meter monster -- nearly the length of two football fields. It is floating here next to a dock, ready to go to sea.

The giant red machine is named after the serpent, one of the few known to thrive in the open sea. The device is designed so that when it's hit by big waves, it writhes snake-like in the water. As it does, its hydraulic pistons move back and forth. They power its generators to produce a rated 750 kilowatts of electricity.

Pelamis is the second generation of "wave energy converters" designed by Pelamis Wave Power Ltd. After some rough sailing, it is beginning to catch on. The machine in the water was ordered and is now owned by giant German power utility E.ON. Another is under order by Scottish Power, and an array of other investors are interested in the product. Still, the company admits, there is much work left to be done.

"We started on a hand-to-mouth basis, and essentially, we are still operating like that," business development director Max Carcas told ClimateWire on a gray and rainy day in the company's sparse offices in a cavernous building here, formerly used to manufacture generators.

But right opposite from where the Pelamis machine is moored is the visible reason why its clean power is seeing rising demand. There are great mounds of imported coal being loaded onto rail cars for shipment to a local power station to be burned and release thousands of tons of climate-changing carbon into the atmosphere.

"That," said Carcas wryly, "is our competition. Romanian coal."

It is never easy to take an untried idea and make it commercial. When the technology is cutting-edge, the environment in which it will operate is unforgiving. The payback is commercially uncertain, although the project is morally praiseworthy. And the gulf between political rhetoric and financial reality is often vast.

Pelamis is the brainchild of three engineers -- Richard Yemm, who is now the company's chief technical officer, Chris Retzler and Dave Pizer. When they founded the company in 1998, they had between them some 40 years of experience in hydraulics and engineering.

Simple concept, complex engineering
The concept is both simple and highly complex, with the new machines consisting of five segments hinged together in line astern, each segment containing a generator. Running between each segment are the hydraulic pistons. As the snake, which is moored by the nose to let it turn into the waves, undulates with the sea movement, so the pistons operate and the electricity flows.

"In the second-generation machines, the segments can also flex from side to side, so we can capture more of the wave power, and that can all be fine-tuned from ashore according to the sea conditions," explained Carcas.

Initially working out of a small apartment and eking out an existence, Yemm had to sell a system he had devised to damp vibrations in wind turbine blades in order to raise seed money.

Using this and his somewhat burdened credit card to move forward with design and wave-tank testing of Pelamis models, they also took advantage of U.K. government support to scrape together enough cash in 2001 to keep the company going for six months and to build a one-seventh scale working model that they put in the water in Scotland's Firth of Forth.

This now-dismantled 20-meter-long (21.9-yard-long) prototype still sits gathering dust in a shed next to where its giant second-generation descendant lies bobbing gently on the tide. But the prototype helped the team raise its first venture capital -- £7.5 million from four investors. In 2004, they built the first full-scale machine, which was 120 meters (131.23 yards) long and had a diameter of 3.5 meters (3.83 yards).

This was towed up to the Orkney Islands north of Scotland, which are home to the European Marine Energy Centre, a government-funded test center for wave machines. It had the network connections in place for tests that would prove impossibly expensive if each fledgling wave machine company had to finance them itself.

"That led in 2005 to our first order -- for three machines -- from Portuguese company Enersis. We had these three machines in the water and generating power to the grid in 2008," said Carcas. "Then things began to go wrong."

Tight money, but it begins to flow
Enersis was taken over in late 2005 by Australia's second-biggest investment bank, Babcock & Brown, which then ran into major trouble as its share capital crumbled in mid-2008. It was forced by its creditors to offload its acquisitions before going into voluntary liquidation in early 2009.

At the same time, the unique suspended mooring system for each machine developed a fault, and instead of floating about 15 meters below the tethered snakes, the system began to sink and drag the snakes down with it. The company also found unexpected wear on the hydraulic pistons, also called rams.

These problems were fixed by Pelamis under its service contract with Enersis, but it was bad publicity and even worse timing because of the financial woes of the owner. An investment group including EDP -- Energias de Portugal -- eventually moved in to take over the project in July 2009.

"It had a much more measured approach than Babcock & Brown, which wanted to go for major expansion," said Carcas. "It took the view that the experience gained from the first three machines had essentially been a learning and proving process. And we were already working on the second-generation machine putting that knowledge to practical use."

Those first three machines are currently sitting in harbour in Portugal, their fate undecided.

Meanwhile, Pelamis is looking into the future. Once sea trials for the new snake are completed, the second-generation machine will be towed up to Orkney and linked up to the European Marine Energy Centre to start generating clean power to the grid.

Money has always been tight, but now the company has a core of 16 institutional investors that over the years have put £43 million ($63 million) into it, and it has so far generated £20 million ($29.3 million) of orders.

One way to protect pristine environments
And to make it better, the utilities are starting to come knocking. E.ON and Scottish Power have both recently won offshore leases from the U.K. government to use Pelamis technology, and the company itself has secured its own lease -- obviously with the goal of using its own machines.

Added together, they come to 150 megawatts of potential power -- enough to power 75,000 homes.

Carcas is sure that the United Kingdom, which has been calculated to have triple the potential wave power it needs to produce all of the country's electricity, will have its first wave farm within five years.

Starting with a farm of, say, 10 to 20 megawatts, he sees that climbing steeply into the hundreds of megawatts. But there is a problem. The U.K. government support scheme that gave wave power its vital boost in 1998 has gone, and the wave power industry now only gets the same level of support as offshore wind.

"My message to the U.K.'s new government, which after all did describe itself as the greenest the country had ever had, is, 'Give us the support we need. The time is right. Delays and procrastination will be the death of us,'" Carcas said.

He sees wave power eventually providing some 20 percent of the United Kingdom's electricity needs, backing up the variability of the burgeoning wind power industry, which is set to rise to some 33 gigawatts within a decade.

Carcas also sees a potential renewable upside to the BP oil catastrophe in the Gulf of Mexico. "It highlights the lengths we are having to go to in search of oil, and the pristine environments that will be at risk. If this disaster makes people think again about the costs of going after increasingly inaccessible oil and therefore look more closely at the alternatives like renewables, then maybe something good can be salvaged," he said.

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500

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