If you’ve ever been flattened by a wave at the beach, you don’t need me to tell you the ocean packs a punch. Getting that punch into a power line is a whole different problem. Engineers have been chasing wave power for decades, and it’s still mostly stuck at test sites and small demonstration plants while wind and solar have gone mainstream.<\/p>\n
So it’s kind of refreshing to see a wave energy update that’s mostly about road transport and maintenance.<\/p>\n
Carnegie Clean Energy, an Australian company listed on the ASX, told investors on October 29 that it’s finished building the buoy at the center of its CETO wave energy system. The buoy was made locally in the Basque Country, in northern Spain, and it was designed as three separate sections to make it easier to move by road.<\/p>\n
Those sections are headed to the Port of Bilbao. Carnegie plans to put them back together on the dock, fit extras like fenders, lift the finished buoy into the water and tow it out to its test berth. You can read the whole update in Carnegie’s ASX filing<\/a>.<\/p>\n Carnegie calls the buoy a buoyant actuator, which is a pretty grand name for what’s basically a big submerged float. The company describes it as the system’s prime mover, and it wants to start deploying it this month.<\/p>\n A lot of the wave machines you’ve probably seen photos of bob around on the surface or sit inside a breakwater. CETO doesn’t. Its buoy sits fully submerged, a few yards under the surface, and it’s tied to the seabed by three tethers.<\/p>\n As waves roll over the top, the buoy gets shoved around, and that pulls on the tethers. Inside the buoy, a power take-off turns the pull on those lines into rotation that spins a generator.<\/p>\n If you haven’t run into the term before, a power take-off is just the bit of a machine that turns movement into useful power. On a wave device, it’s basically the drivetrain. Wave Energy Scotland, one of the two agencies running the EuropeWave program<\/a> that’s backing this project, compares Carnegie’s version to a winch.<\/p>\n Carnegie’s control system can also shift the buoy’s position and angle in the water. Wave Energy Scotland says that helps it soak up more energy and ride out rough seas, and it claims the current design can capture nearly twice as much energy as the one Carnegie deployed before. That’s a program talking up a technology it chose to fund, so I’d treat that number as a target until real sea data comes in.<\/p>\n Road transport is the reason Carnegie gives for the three sections. But the modules that go inside the buoy are where things get more interesting.<\/p>\n During fabrication, Carnegie ran physical fit tests that confirmed three power take-off modules and one electrical module can all be slotted into the buoy and pulled back out again. The company says any of them can be swapped for a spare, which should mean a quick turnaround whenever the machine needs maintenance. SKF, the Swedish bearing giant, is assembling the power take-off modules, and the electrical module was put together with a Basque supplier called SEI.<\/p>\n That might sound like a minor engineering footnote. I’d argue it’s one of the more sensible things in the whole announcement. The ocean is a lousy place to fix anything. Every trip out needs a boat, a crew and a decent weather window. And the Bay of Biscay in winter doesn’t hand those out very often.<\/p>\n So say one of the generators acts up in February. Instead of sending people out to work on it at sea, the idea is that the faulty module gets lifted out, a spare goes in, and the broken one gets fixed in a workshop ashore.<\/p>\n What Carnegie hasn’t spelled out in this update is whether that swap happens at sea or whether the buoy has to be towed back to port first. That’s a pretty big detail, since it decides how quick that turnaround really is.<\/p>\n The first stage, which Carnegie says starts in November, covers the buoy and an initial mooring system at its berth on the Biscay Marine Energy Platform, or BiMEP. The power take-off modules won’t be inside yet. Carnegie says this round is meant to check the buoy’s hydrostatic characteristics, how well it tows and whether the local offshore supply chain can handle the job.<\/p>\n Hydrostatics sounds intimidating, but it’s basically the question of whether the thing floats and sits in the water the way the computer models said it would. It’s a pretty important box to check before you fill it with expensive generators.<\/p>\n So does that mean this buoy’s about to start feeding Spain’s grid?<\/p>\n Not this year. Carnegie plans to finish assembling the power take-off modules, test them onshore with the electrical module and controls, and then take them to port to be fitted into the buoy. The full system is supposed to be deployed and connected to the grid next spring, once the Basque winter is over and the weather windows for that kind of work get better. I can’t blame them. I wouldn’t want to be hooking up a power cable off northern Spain in January either.<\/p>\n BiMEP is a test site run by the Basque Energy Agency off Armintza, a small coastal village not far from Bilbao. According to PRIMRE, a US marine energy database, the site starts at least a mile offshore, sits in 164 to 295 feet of water, covers about 2 square miles that are closed to shipping and has 20 megawatts of grid connection split across four 5-megawatt hookups.<\/p>\n If the name rings a bell, it’s the same test site where a Basque spar buoy called MARMOK-A-5<\/a> was towed out earlier this year. Both machines made it into the final phase of EuropeWave, and the Basque coast already has a much older wave plant built into the Mutriku breakwater<\/a>.<\/p>\n The machine Carnegie’s sending out is a scaled demonstrator rated at 80 kilowatts. That isn’t much. It’s a test rig built to produce data, and Carnegie’s also developing a separate 6-megawatt CETO array project at BiMEP, which gives you a sense of where it wants this to go if the demonstrator works out.<\/p>\n One thing you won’t find in the filing is how big the buoy actually is. Carnegie doesn’t give a diameter or a weight, which is a little frustrating when the headline feature is a design that comes apart to travel by road. Hopefully the photos from the Bilbao dock fill in that gap.<\/p>\nSo what is CETO?<\/h2>\n
So why build it in pieces?<\/h2>\n
What happens this month?<\/h2>\n
BiMEP is a busy little patch of ocean<\/h2>\n
Carnegie has done this before, sort of<\/h2>\n