Wave power has been slow to take off, but it looks like things are accelerating. Last week, EU’s Gibraltar made a big buzz over the official grid connection of its new wave power project, an array of ocean energy converters from the company Eco Wave Power. Though modestly sized, it is the first clean power plant of its kind in the EU, and Gibraltar plans to leverage it to strive for a 100% renewable energy profile.
The last time CleanTechnica checked into Eco Wave Power, the technology was still in the development phase, so we have a lot of catching up to do. For that matter, if you haven’t caught up with Gibraltar recently, the nation still technically falls under British sovereignty and is a member of the EU as a British Overseas Territory (if you have an idea what Brexit means for BOTs, drop us a note in the comment thread).
Wave Power Is Scaling Up
The first time CleanTechnica checked in on Eco Wave Power, the company had just completed a successful test of medium-scale versions of its two wave power models, the Wave Clapper and Power Wing, in the Black Sea in May of 2012.
Apparently, that was enough to impress China. In November 2012, Ocean University of China sent a high-level delegation to EWP’s home base in Israel to sign an agreement for the company to develop its first commercial-scale wave power technology in China.
The project gathered steam last year, when Eco Wave Power’s Chinese subsidiary received permission to build a 100-kilowatt plant on Zoushan Island in the eastern Zhejiang province.
Since then, China has been rather quiet (if you can find some news, drop a note in the comment thread), but in the meantime, the Gibraltar wave power project has skipped ahead.
In 2014, EWP signed a power purchase agreement with Gibraltar for delivery of a 5 megawatt ocean power plant, and last year, construction began on the Gibraltar plant, located at the Ammunition Jetty.
The new array, located at the Ammunition Jetty, is composed of 8 ocean energy converter units (more on those in a second). In its current iteration, the plant clocks in at 100 kilowatts.
The bulk of the wattage will be added later with the help of an EU grant, in phases, from 1 megawatt to 5 megawatts. The additional units will be much larger and are currently in the design phase.
When fully built out, the plant is expected to meet 15% of Gibraltar’s electricity demand.
As for first-of-its-kind, the company claims that the Gibraltar array is the first grid-connected, multi-unit wave power plant “anywhere in Europe” to operate under the terms of a commercial power purchase agreement.
How It Works
Ocean energy conversion takes many forms, but they all share two challenges that are not operational for land-based renewable energy harvesters. Saltwater corrosion is a big one, and the ability to handle severe weather — a combination of high wind and high seas — comes in a close second.
That could be about to change. Eco Wave Power has been working on its ocean energy conversion technology since 2011, and it is still fine-tuning its models based on lessons learned from a test bed in Ukraine and a pilot plant in Israel, at Jaffa Port.
The Eco Wave Power technology is based on a familiar concept, in which a floating platform moves up and down with the waves. The motion of the platform, or buoy, triggers kinetic activity in whatever equipment is attached to it.
So far, the company has developed two versions, the Wave Clapper and the Power Wing.
One of the company’s key improvements was to tailor the shape of the float, in order to draw more motion out of the same wave. Other improvements involve hydraulic systems that enable the float to maintain its most efficient position through seasonal or weather-related changes in the water level.
The float can shift orientation slightly as needed, in order to maintain a maximum “angle of attack” relative to incoming waves.
The trick is to convert all that activity into an electric current. One fairly common solution is to deploy the motion of the float to create pressure in a hydraulic fluid, which can then be used to power a generator.
Some wave power devices are designed with onboard generators, and the electricity is shipped to land via undersea cable.
EWP’s solution is to ship the pressurized fluid to a generator on land. Aside from ease of access for maintenance and repair, the land-based power plant has the advantage of protecting sensitive offshore environments from accidental spills or releases of the hydraulic fluid and other potentially toxic substances.
What About Corrosion And Storm Protection?
The coatings industry doesn’t cross the CleanTechnica radar all that often, but the Eco Wave Power announcement is a good reminder that R&D advances in corrosion protection are absolutely essential to continued progress in the renewable energy field, for solar and wind as well as ocean energy.
Eco Wave Power states that its advanced coatings, combined with a unique arrangement of cathodes, provides its technology with a lifespan of at least 30 years and up.
As for durability in heavy seas, the units are designed to absorb the shock from occasional rogue waves as well as a series of high waves. The units are typically anchored to a jetty, breakwater, or other protruding structure, and in extreme conditions, they can be lifted above the threat line, from a horizontal to a vertical position.
The same hydraulics used for energy conversion are deployed to do the lifting, which avoids the expense of adding a separate system for that function.
Eco Wave Power also offers a mobile solution for locations with shoreline conditions that preclude jetties or similar structures.
Many Waves In The Sea
The next couple of years should be big ones for wave energy technology around the world. Eco Wave Power is already gearing up for 111 megawatts worth of projects in the near future, with a subsidiary in Mexico in addition to China and Gibraltar. The company has also let out word that more subsidiaries are in the works.
Image (cropped): via Eco Wave Power.
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