To remind, the MeyGen project’s Phase 1A involved the installation of the AR1500 onto a gravity-based foundation, alongside three other AH1000 MK1 turbines, to form an array of 6MW.
From what I've found, the AR1500 has just had routine quarter-life maintenance[2], but I can't find anything concrete right now which of the four made the 6 year milestone. I do note that in the brochure[3] for the AR1500 they claim three service intervals every 6 1/4 years, rather than four service intervals as indicated by the article.
GPs link doesn't even show what was claimed ("The other 3 have needed costly maintenance").
From that link:
"The first of these turbines is scheduled for redeployment in May 2022, with the final turbine to be deployed in March 2023, complete with a retrofitted wet mate connection system, which more than halves the costs of future turbine recoveries and deployments."
"The company’s AR150 turbine was re-deployed last month, after being out of the water for upgrade and maintenance work."
The single long-running turbine can be compared to the upgraded turbines to measure the effect of the upgrades, and it provides the headlines this thread is about. The upgrades themselves are also clearly valuable R&D work.
Also there is theoretically power in the GW range to be harvested here (specifically, Scotland’s tidal flows), so it’s worth investing a substantial sum to figure this tech out.
Over many years, I've yet to hear of an ocean based power generating system that comes anywhere near the $ per kWh cost produced by just covering some less-useful land in ground mount photovoltaics.
Private, entirely for profit companies, have recently answered large government tenders in the middle east to sell power at the equivalent of $0.05 USD per kWh. They are fairly confident that they can make a profit doing this, even with the cost to incur the long term debt to privately build a massive solar power plant.
The cumulative amount of solar power being produced within Germany right now is a good example of its practical use in a less sunny climate.
In terms of placing things in the ocean, hiring the sort of offshore work vessel with a built-in crane can go and place or remove multi ton apparatus is very costly. Maritime construction for things like laying coastal submarine cable, building piers and docks and marinas, setting and maintaining marker buoys isn't cheap.
Laying and maintaining HV AC or DC submarine cables in salt water is also particularly known to be expensive. Hiring a 36'-42' aluminum landing craft for coastal construction projects, with fuel and crew can be easily $500 an hour.
Labor and vehicle costs are greatly increased compared to doing things on dry land.
I used to think the same way, “just use cheaper solar” but I have come around to see the value. Doing science and engineering projects to explore new or different alternatives is valuable. We might find something surprising.
Having different types of power generation provides redundancy. The wind still blows at night, the tide still comes in and out when its cloudy, etc. Grid storage is nowhere near a solved problem, so something like tidal could prove less expensive than storage or overbuilding alternatives to overcome their variability problems. Even if it doesn’t end up being widely useful, it could still end up finding a use in more niche applications.
Finally, it can and will improve. 30 years ago, solar was not price competitive and decades of development and iterative improvements have changed that. We should keep developing alternatives to see their full potential.
I think the charm for a cloudy place like Scotland is that a system like this is unaffected by poor light supply. Your photovoltaics aren't going to fair nearly so well there hence this solution.
> covering some less-useful land in ground mount photovoltaics.
Doesn't even need to be less-useful land (especially in western Europe, ground is becoming a scarce resource), put PV on flat rooves or add them over open car parks. Also helps alleviate pressure on the overstressed energy grid by generating and using power more locally.
But, local power is (overall) a lot more costly than major centralized power generation projects, like a wind farm or what have you.
I'm not a turbine, or power generation, expert but I am almost 100% sure that no non-solar power generation method can operate without being taken down periodically for maintenance.
How do the maintenance costs (and intervals) of these compare to gas/steam turbines?
I assume corrosion is to blame? Crazy how much ocean facing stuff is still done with painted steel. You'd think aluminum and carbon fiber or even plastic would be making strides but it's still the iron age in many ways it seems.
Carbon fibres themselves may be corrosion resistent, but the fibers by themselves are like a fabric. If you want a solid part instead of cloth, you need to encase the fibers in a resin. Imagine it like a piece of cloth soaked in beeswax or candle wax: it is solid like the resin but if you pull on it, it has the strength of the fibers of the cloth.
The resins used for carbon fibers are usually very bad at contact with water over long periods of time. Even those in aerospace applications require coating/paint if exposed moisture over time. It’s a plastic, even the best ones don’t do so well in water after a few months.
Furthermore, the damage that moisture does to the resin can be difficult to detect and even more difficult if not impossible to fix. It requires clean rooms, skilled labor and machinery that you don’t have in the middle of an ocean.
Then take iron corrosion: it is easy to spot by naked eye, it may not be easy to repair, but it is relatively simple to “halt” further damage by removing the rust and adding new paint.
Don’t get me wrong: carbon fibers are amazing, but sometimes the “boring” solution is best.
PS: steel alloys and coatings can be amazingly high tech too, it’s amazing what can be engineered.
All industrial generators undergo regular shutdowns for maintenance and recalibration. This is costly and time consuming when they are on land.
Also, I am thinking about all the ocean factors beyond salt corrosion. There's tons of crap in the water beyond salt and minerals. Like fine grit suspended in it. Plus the tidal forces etc.
Steel has the benefit of fatigue limit. Which means as long as the cyclic stress on steel is under a certain amount it won't fail. Aluminium has a much lower fatigue strength than steel and will always fail given enough cycles.
While rust can be a problem it can be mitigated. Also steel is easier to repair than many other materials (welding).
BTW. Aluminium does suffer from corrosion as well. I used to have racing bike, the wheel nipples (these connect the spokes to the wheel rim) used to corrode to the point where they would fail, which meant I would end up with a buckle. I ended up having both wheel rebuilt with higher quality brass nipples.
Plastics under time also suffers from a different set of issues. Plastics can become brittle. Anyone working on old computers (especially macs) can attest to this.
Corrosion, the force of water (being 800 times as dense as air and effectively incompressible, water forces can be huge), objects in the water (again, water being heavy it can move heavy objects around in its flow), fouling through, for example, algae and mussels (https://en.wikipedia.org/wiki/Fouling)
magicalhippo|7 months ago
To remind, the MeyGen project’s Phase 1A involved the installation of the AR1500 onto a gravity-based foundation, alongside three other AH1000 MK1 turbines, to form an array of 6MW.
From what I've found, the AR1500 has just had routine quarter-life maintenance[2], but I can't find anything concrete right now which of the four made the 6 year milestone. I do note that in the brochure[3] for the AR1500 they claim three service intervals every 6 1/4 years, rather than four service intervals as indicated by the article.
[1]: https://www.offshore-energy.biz/simec-atlantis-troubleshooti...
[2]: https://www.offshore-energy.biz/overhauled-meygen-turbines-t...
[3]: https://simecatlantis.com/wp-content/uploads/2016/08/AR1500-...
unknown|7 months ago
[deleted]
Havoc|7 months ago
If 1/4 make it then you at least know it can be done and hopefully learned a couple key failure modes from it
terribleperson|7 months ago
dinfinity|7 months ago
From that link:
"The first of these turbines is scheduled for redeployment in May 2022, with the final turbine to be deployed in March 2023, complete with a retrofitted wet mate connection system, which more than halves the costs of future turbine recoveries and deployments."
"The company’s AR150 turbine was re-deployed last month, after being out of the water for upgrade and maintenance work."
The single long-running turbine can be compared to the upgraded turbines to measure the effect of the upgrades, and it provides the headlines this thread is about. The upgrades themselves are also clearly valuable R&D work.
micromacrofoot|7 months ago
contravariant|7 months ago
badestrand|7 months ago
1.5 MW is nothing to scoff at, so if it costs a bit in maintenance that's okay. But overall costs would be great to know.
padjo|7 months ago
pyrale|7 months ago
The article likely double-dips on this by saying that 6MW could provide for 7k homes, which it obviously can’t at peak use.
theptip|7 months ago
unknown|7 months ago
[deleted]
mlyons1340|7 months ago
https://www.ercot.com/gridmktinfo/dashboards
walrus01|7 months ago
Private, entirely for profit companies, have recently answered large government tenders in the middle east to sell power at the equivalent of $0.05 USD per kWh. They are fairly confident that they can make a profit doing this, even with the cost to incur the long term debt to privately build a massive solar power plant.
The cumulative amount of solar power being produced within Germany right now is a good example of its practical use in a less sunny climate.
In terms of placing things in the ocean, hiring the sort of offshore work vessel with a built-in crane can go and place or remove multi ton apparatus is very costly. Maritime construction for things like laying coastal submarine cable, building piers and docks and marinas, setting and maintaining marker buoys isn't cheap.
Laying and maintaining HV AC or DC submarine cables in salt water is also particularly known to be expensive. Hiring a 36'-42' aluminum landing craft for coastal construction projects, with fuel and crew can be easily $500 an hour.
Labor and vehicle costs are greatly increased compared to doing things on dry land.
542354234235|7 months ago
Having different types of power generation provides redundancy. The wind still blows at night, the tide still comes in and out when its cloudy, etc. Grid storage is nowhere near a solved problem, so something like tidal could prove less expensive than storage or overbuilding alternatives to overcome their variability problems. Even if it doesn’t end up being widely useful, it could still end up finding a use in more niche applications.
Finally, it can and will improve. 30 years ago, solar was not price competitive and decades of development and iterative improvements have changed that. We should keep developing alternatives to see their full potential.
gleenn|7 months ago
Cthulhu_|7 months ago
Doesn't even need to be less-useful land (especially in western Europe, ground is becoming a scarce resource), put PV on flat rooves or add them over open car parks. Also helps alleviate pressure on the overstressed energy grid by generating and using power more locally.
But, local power is (overall) a lot more costly than major centralized power generation projects, like a wind farm or what have you.
insane_dreamer|7 months ago
all systems require maintenance, so "costly" is relative; would need more specifics to determine whether this is a cost effective solution or not
os2warpman|7 months ago
How do the maintenance costs (and intervals) of these compare to gas/steam turbines?
asdff|7 months ago
saturnV|7 months ago
The resins used for carbon fibers are usually very bad at contact with water over long periods of time. Even those in aerospace applications require coating/paint if exposed moisture over time. It’s a plastic, even the best ones don’t do so well in water after a few months.
Furthermore, the damage that moisture does to the resin can be difficult to detect and even more difficult if not impossible to fix. It requires clean rooms, skilled labor and machinery that you don’t have in the middle of an ocean.
Then take iron corrosion: it is easy to spot by naked eye, it may not be easy to repair, but it is relatively simple to “halt” further damage by removing the rust and adding new paint.
Don’t get me wrong: carbon fibers are amazing, but sometimes the “boring” solution is best.
PS: steel alloys and coatings can be amazingly high tech too, it’s amazing what can be engineered.
zikzak|7 months ago
Also, I am thinking about all the ocean factors beyond salt corrosion. There's tons of crap in the water beyond salt and minerals. Like fine grit suspended in it. Plus the tidal forces etc.
ReaperCub|7 months ago
While rust can be a problem it can be mitigated. Also steel is easier to repair than many other materials (welding).
BTW. Aluminium does suffer from corrosion as well. I used to have racing bike, the wheel nipples (these connect the spokes to the wheel rim) used to corrode to the point where they would fail, which meant I would end up with a buckle. I ended up having both wheel rebuilt with higher quality brass nipples.
Plastics under time also suffers from a different set of issues. Plastics can become brittle. Anyone working on old computers (especially macs) can attest to this.
Someone|7 months ago
dzhiurgis|7 months ago
spandrew|7 months ago
KolibriFly|7 months ago
Goronmon|7 months ago
As opposed to other forms of energy production which have free/zero maintenance?
unknown|7 months ago
[deleted]
dietr1ch|7 months ago
varispeed|7 months ago