5 ms·

> taller they get, the harder they will be to repair If they’re floating couldn’t we have a mechanism to sink them to a reasonable height during repairs? Or i

> taller they get, the harder they will be to repair If they’re floating couldn’t we have a mechanism to sink them to a reasonable height during repairs? Or it wouldn’t seem to be that hard to have ships with large ladders or a crane for repairs. (I couldn’t read the article because it’s completely paywalled.)

flavius29663 5y ago
Interesting idea. I think the problem is with getting salty water everywhere. Salt is the main killer out on the ocean. Also, it you lower it enough you will end up with the blades in the water, I really don't think you want that during wavey weather. Anyway, this extra height would solve a non-problem. It makes little difference if a human has to climb 100 or 300 meters. It's still work at heights - same kind of protocols and gear. If it's something that the humans can't fix (replace the gearbox or something massive) - then you need a crane anyway. Maybe the only issue would be with the waves moving the turbines enough to make the humans seasick at that height. Not sure, I can't see the whole article.
- throwaway0a5e 5y ago
  It's basically a fiberglass tube. Corrosion from a quick dunk is a trivially solve-able issue since everything that could corrode will already need to be protected enough fora decades long service life in salt spray. I can't see sinking it for routine maintenance being cost effective. Even at a hundreds of dollars per man hour it's still probably not gonna be cheaper than making the maintenance people climb a ladder. That said, being able to lay over the main tube at like 60deg would make it way easier to construct them since you could use a much smaller and cheaper crane to assemble and it would minimize the side to side movement caused by rolling. You basically just need a cleverly engineered chamber to pull that off since the ship can have all the pumping hardware.
  - flavius29663 5y ago
    > lay over the main tube In my opinion, the main tubes are nowhere near strong enough to support the weight that way! They are weaker than they appear. The companies can built them so high because they gave up the idea that the tower can withstand any wind thrown at it and still oppose the wind enough to produce energy. Instead, smart computer programs turn the propeller angles independently, so that when the blade reaches the top (where it exerts maximum torque trying to topple the tower), it is angled such that it won't catch too much wind. Then when the blade is near the bottom, it's turned again in order to capture most wind.
xondono 5y ago
It’s technically possible, but this things are barely cost effective already. A system for sinking them and raise them for repairs would be too expensive. As for ships, they already use custom barges, but if they’re deployed somewhere it’s because there’s heavy winds, so most repairs need to be workable even in (somewhat) adverse conditions. This also makes matters worse, because you don’t want your ship to be tied to a massive windmill if the wind picks up.
- WJW 5y ago
  > but this things are barely cost effective already. This really needs some citations. Wind turbines at sea typically have well in excess of 15% return on investment over their expected lifespan and are being financed without any government subsidies these days. 15+% is not "barely cost effective" territory for this kind of capital intensive infrastructure, that is "how can I reinvest this torrent of income quick enough".
  - xondono 5y ago
    “Wind turbines” and “floating wind turbines” are not the same. Floating wind turbines are not as cost effective as their stationary counterparts.
jcampbell1 5y ago
The article talks about how oil service crane ships are designed for heavy, not high. There are prototype crane ships for the task, but they cost $250 million minimum which hampers growth of offshore wind installation. The issue is the blade length and positional stability, so sinking isn’t much of a solution. My takeaway is that this is promising but a few engineering feats from being economically sensible.
void_mint 5y ago
Some offshore turbine companies have developed a lift that attaches external to the base and carries people up. There’s a lot of interesting technology in the space - the maintenance cost is the most difficult (at least, in my experience) so there’s lots of research and innovation happening to lower that cost. When I stopped working with them, the company I worked for was using drones to take high res images of turbine blades to better plan for what to work on, rather than just climbing up and looking.

flavius29663 5y ago

Interesting idea. I think the problem is with getting salty water everywhere. Salt is the main killer out on the ocean. Also, it you lower it enough you will end up with the blades in the water, I really don't think you want that during wavey weather. Anyway, this extra height would solve a non-problem. It makes little difference if a human has to climb 100 or 300 meters. It's still work at heights - same kind of protocols and gear. If it's something that the humans can't fix (replace the gearbox or something massive) - then you need a crane anyway. Maybe the only issue would be with the waves moving the turbines enough to make the humans seasick at that height. Not sure, I can't see the whole article.

throwaway0a5e 5y ago
It's basically a fiberglass tube. Corrosion from a quick dunk is a trivially solve-able issue since everything that could corrode will already need to be protected enough fora decades long service life in salt spray. I can't see sinking it for routine maintenance being cost effective. Even at a hundreds of dollars per man hour it's still probably not gonna be cheaper than making the maintenance people climb a ladder. That said, being able to lay over the main tube at like 60deg would make it way easier to construct them since you could use a much smaller and cheaper crane to assemble and it would minimize the side to side movement caused by rolling. You basically just need a cleverly engineered chamber to pull that off since the ship can have all the pumping hardware.
- flavius29663 5y ago
  > lay over the main tube In my opinion, the main tubes are nowhere near strong enough to support the weight that way! They are weaker than they appear. The companies can built them so high because they gave up the idea that the tower can withstand any wind thrown at it and still oppose the wind enough to produce energy. Instead, smart computer programs turn the propeller angles independently, so that when the blade reaches the top (where it exerts maximum torque trying to topple the tower), it is angled such that it won't catch too much wind. Then when the blade is near the bottom, it's turned again in order to capture most wind.

xondono 5y ago

It’s technically possible, but this things are barely cost effective already. A system for sinking them and raise them for repairs would be too expensive. As for ships, they already use custom barges, but if they’re deployed somewhere it’s because there’s heavy winds, so most repairs need to be workable even in (somewhat) adverse conditions. This also makes matters worse, because you don’t want your ship to be tied to a massive windmill if the wind picks up.

WJW 5y ago
> but this things are barely cost effective already. This really needs some citations. Wind turbines at sea typically have well in excess of 15% return on investment over their expected lifespan and are being financed without any government subsidies these days. 15+% is not "barely cost effective" territory for this kind of capital intensive infrastructure, that is "how can I reinvest this torrent of income quick enough".
- xondono 5y ago
  “Wind turbines” and “floating wind turbines” are not the same. Floating wind turbines are not as cost effective as their stationary counterparts.

jcampbell1 5y ago

The article talks about how oil service crane ships are designed for heavy, not high. There are prototype crane ships for the task, but they cost $250 million minimum which hampers growth of offshore wind installation. The issue is the blade length and positional stability, so sinking isn’t much of a solution. My takeaway is that this is promising but a few engineering feats from being economically sensible.

void_mint 5y ago

Some offshore turbine companies have developed a lift that attaches external to the base and carries people up. There’s a lot of interesting technology in the space - the maintenance cost is the most difficult (at least, in my experience) so there’s lots of research and innovation happening to lower that cost. When I stopped working with them, the company I worked for was using drones to take high res images of turbine blades to better plan for what to work on, rather than just climbing up and looking.