I just wanted to say that I found this website does an excellent job of communicating exactly what they are offering, what they previously accomplished, and what they are planning to do next.
I wish more startups, or any large project in general, had this type of site.
Actually, both, because they are "trying to cover for the fact that they don't have anything ready to offer and haven't previously accomplished anything" precisely "to look good to raise funds and/or be acquihired by one of the big ones".
But it does mean that the infrastructure side of it is well understood by the company as it has vast experience of building large installations in the North Sea, both fixed and floating.
So the question is rather is it economically viable?
I have said it in another comment which has been downvoted but just to answer your question, I'll say it again. They are not doing this because of economic viability. If it was economically viable, it wouldn't take Statoil to do it; numerous startups would find investments to do it. They are doing it as an "investment in renewables" to keep the eco-terrorists happy.
Fairly sure hywind is a 'demonstrator' project used to assess feasibility of large scale deployments +1GW, not just something to keep eco warriors at bay.
Subsidy free traditional offshore wind is happening, but this requires good site conditions for installation, cracking subsidy free floating wind would open up much larger spaces of ocean to development and thus more power and profit! Win win!
Offshore wind farms require bidding for concession areas from government. It requires complex design, survey and consenting work. And it needs a prestigious amount of money. A large scheme will spend more than a billion to get constructed. Of course speculators and startups could try. But oil companion have all the right expertise and access to capital. The big opportunity for startups is providing services to the developers.
Not so much, as you might expect for a demo like this. 40 million euro should get you from concepts as by the startup list to competing for tenders on wind farms. That is in comparison to monopile or jackets off-shore.
The kind of things oil companies have to do to please the eco-terrorists.
People who have to pay for oil and everything it helps us create/transport (basically everything) are forced to pay for this, thanks to eco-terrorists, while tried and tested nuclear power will last us thousands of years.
Unlike nuclear and coal, this will harm the aquatic life and birds more... but those things only matter when you are speaking against their narrative.
(Not OP, and) Not sure about aquatic life, but if those turbines are anything like the ones on land, then the rotors are definitely NOT spinning slowly! And they look even bigger, which would imply a faster speed at the rotor tip for the same rotational velocity.
And as a result there have been issues with them killing lots of birds, esp 1) IIRC large predatory birds which are looking down at the ground for prey and can't change course as easily as a small bird, and 2) being in migration paths. But I think both of those problems are pretty well understood by now and I'm guessing this project takes both into account.
> if those turbines are anything like the ones on land, then the rotors are definitely NOT spinning slowly!
You apparently haven’t seen modern (ie installed in the last 5 years, this stuff moves quickly) wind turbines. They are huge and slow turning, also much quieter than the smaller, shorter, faster spinning ones.
The rotors turn slow in terms of rpm but fast in terms of wingtip speed, due to the very large radius. But many things kill birds, I do not believe that wind turbines could ever make much of a difference.
As an example, the Vestas V164-8MW seems to be one of the largest off-shore wind turbines, and has a rotor diameter of 164m and a rotational speed of between 4.8 and 12.1rpm. [1]
Unless I'm miscalculating, that means that the tip of one of the rotors will travel 515 metres per revolution, which at 4.8-12.1rpm is a tip speed of between 2,472 metres per minute and 6,231 metres per minute.
To put that in more common units, that's between 148km/h and 373km/h.
Yes all correct. Those top 'tip' speeds where reached with smaller turbines as well. Max tip speed is a design limitation on blades (induced vibrations due to turbulence). What it means is that small turbines had much higher RPM, and the average speed along the blade was much higher in smaller turbines.
Second benefit of larger turbines is much more of the swept area is outside of the normal flight heights of birds. Either too low for migration patterns or too high for most hunting and scooting flight heights (relative to nearest surface).
So one 8MW turbine is likely to kill a lot less than 8 * 1 MW and much, much less than 80 * 100kw, even if it has a much larger swept area.
Now as these are offshore turbines, and Hywind, being for quite deep water. Likely to be far offshore, there are not that many birds around too get hit in the first place.
The nice thing about the slower RPMs compared to smaller tubines (especially pre 2000's) is that slower RPM's make it easier to spot the turbine for birds. High RPM's give optical effects that make it hard to predict where something is going (e.g. wheel looks like rotating backwards etc...) so bigger is easier too avoid for birds.
If wind farms are going to contribute significantly, then there will be a lot of them. In terms of replacing fossil fuels they will likely still be a net benefit, but unless the Audubon Society has been captured by Big Oil etc (which I doubt, but possible) then bird safety still sounds like an open question.
I would be very happy with all birds being extinct if that is what would take to come up with a solid replacement for fossil fuels. The problem with wind power is it will not replace anything. Wind cannot provide reliable power so it has to be backed by something else that is reliable. Also, wind provides variable power so infrastructure has to be setup such that it can handle such variation.
After accounting for initial setup costs and maintenance of wind turbines (it is worse than Solar in this regard because of the wear and tear in mechanical parts) and power infrastructure (which has to be designed to handle such variation without any impact on consumers), it will take a very long time to break even, if at all. And don't forget that we will still need something reliable like nuclear or fossil fuels to back it up... which we already have enough of to last for thousands of years.
So, basically, all we get with wind is more work for no gain at all (not to mention the unnecessary environmental harm). I am sure Statoil is not ignorant of this. They are just using a small portion of their 100 billion dollar yearly revenue in this to please the eco-terrorists.
Yes they do, because birds are confused by the light signals at night or during foggy days and go towards them. Big glass windows/walls also kill birds. I work in an office with glass curtain walls and a lot of birds end up flying into them. To make matters worse, we also have stray cats around the building, so birds that fall to the ground and are not dead upon hitting the window end up being lunch.
The ones I'm referring to are in large installations in the last 10 years in the US Midwest. Each rotor blade is transported individually on the back of a flatbed semi-truck.
As pointed out elsewhere in the thread: indeed the RPM can be low, but the rotor tip velocity is high.
Large turbines like the Vestas V164 8.0MW have nominal rotor speeds of ~10RPM. This sounds pretty slow, but with a blade length of 80M, this corresponds to a tip speed of nearly 200mph. Low RPM doesn't mean low tip speeds.
Some types of turbine require pile driving which makes a lot of underwater noise. This can harm dolphins and porpoises. Floating turbines probably don't have this problem.
The blades go very fast at the outer part of the blade. It will easily kills birds.
May well have an impact (no pun intended). I think the more relevant question is how that impact compares to other generation schemes, both in the short term (birds flying into large structures) and the long (habitat loss due to climate change).
It's interesting how HN have quite a bit of right wing extremist comment sprinkle here and there, I always thought it was a rare occurrence.
I also think you simplifying nuclear power. You still need to store the waste and it something quite a few people dislike. And no body is investing in Thorium R&D, at least not in USA.
> aquatic life and birds more
There are several country side plastic patches in the ocean which is cause cause of oil products that cannot biodegrade in a reasonable time.
The global warming cause by oil which in turn cause bleaching, killing aquatic life, causing far more damage than whatever you think wind turbines are causing.
Airplane and free roaming cats kill more birds than wind turbines. I know turbines do kill birds but they can move it away from migration paths.
Right wing of where exactly? I am not American but I am assuming you're talking about the US. In that case, you should know that the clean tech industry in the US started and thrived during Bush presidency. The mainstream American right wingers are no less brainwashed than the American left wingers when it comes to renewables and climate change. Climate change deniers are a minority that even Trump disassociates himself from because he knows majority of the right would hate him for it.
>And no body is investing in Thorium R&D, at least not in USA.
People would invest in it if they thought it would work. It's like Solar and Wind, which are complete waste of money, except it is not "renewable" and hence not even cool.
>I know turbines do kill birds but they can move it away from migration paths.
As I already said, I know that it is okay as long as it fits the narrative.
And use all of the masts as an ELF antenna array. That will give those racks something to think about: subsurface phased-array radar for submarine spotting, earthquake and atmospheric study, etc.
It is important to note that Statoil is majority owned by the Norwegian government so it's priorities are maybe a bit more complicated than more independent multinational oil and gas companies. Although all the big energy companies have major alternatives portfolios and innovations strategies too.
It is also important to mention that this project happened because of the falling oil price, and Statoil needing to find alternative stuff to do. Not diversify their sources of income, but literally give their enployees something to do. A lot of highly educated people lost their jobs in Norway during the last few years, and a windpower project would be one way to get public funding and avoid firing too many employees (this is of political interest, Statoil don't need half of their eployees). I am not saying the project would never have happened, but it probably happened now and not in ten years because of this. Bottom line: this is busywork imposed on a huge, slow, old fashioned oil company which will never be able to compete comercially.
I agree with your bottom line. I was going to say they have talked about wind farms at sea since 2008, but that fits well with what you say. I see I seem too cynical, but i still think they are very late to the game. Especially considering how far denmark have come, given this project probably is inspired by the danish focus on wind power, and the competency of Statoil on offshore constructions.
Could you please cite some evidence for your claim about competing commercially? Also, do you mean the technology in general or this particular effort? Here is a year-old write-up of a survey of experts published in a peer-reviewed journal which asserts that floating wind will be cost-competitive:
Thanks for the clarification. Next: are you asserting Statoil's public ownership by itself is evidence that costs will be higher, or do you have other evidence to support the claim?
First: I would not use my claim to evaluate weather or not i will buy into their solution.
I work in IT, not offshore. My claims are based on living in Norway and reading about Statoil almost daily, and talking to people I know working in offshore, and on IT projects at Statoil. It is hard to find hard evidence for claims about Statoil. The closest thing i can find to evidence is to tell you to just check the headlines on some random Norwegian newspaper. This one is on the front page today: http://e24.no/energi/oljeinvesteringer/frykter-slutten-paa-s... one of the things stated there which could be relevant is that one project scheduled for completion in 2022 has had its construction costs cut in half from 100 billion NOK to 50 billion. Some would say this is evidence of Statoil being able to rationalize well. I would say this is evidence of Statoil having a history of over-spending. It all depends on your point of view, it is next to impossible to get the full picture.
Every oil company (and those serving them) has been overspending in the years of insanely high oil prices. It is not so much about Statoil. Of course people hold somewhat higher hopes for a state-owned company than independently funded private companies.
I have no idea whether they'd be able to compete commercially, but they manage to put a lot of money in a pension fund for all Norwegians: https://en.wikipedia.org/wiki/Government_Pension_Fund_of_Nor...
I wish BP and Shell did the same instead of being "commercially competitive".
If no one buys into their wind farm, there won't be much money to put into the pension fund (I mean it will, they earn money form oil, but no "wind money").
The wind sector has decades (well, roughly two decades I would say) of experience in being permanently undercut by cheaper wind. Moderate shifts in the playing field won't take them by surprise.
At first glance I didn't understand how these things wouldn't tip over under load, but then the video made clear that the ballast extends 78m below the surface. The torque exerted on the turbine/generator itself is probably small compared to the stabilizing resistance provided by the ocean's mass, and the fact that it is secured to the sea floor in 3 directions. Of the two, ocean or sea-floor moorings, I wonder which provides most of the actual resistance to toppling under load.
It requires interesting control systems to keep stable and performing optimally. You can read about some of the challenges here (has some great figures) ...
It appears the tethers are for positional stability, and the keel or whatever you want to call the underwater portion of the structure provides rotational stability, but I'm sure there is much more to it than that.
I guess as with most turbines. Most will remain fixed, only the upper part with generator will rotate. This shouldn't work different to conventional turbines.
If we're talking about the spar-type hywind base in the video:
Its catenary mooring system resists rotation of the turbine hull. How much so, I can't say.
I suspect that by far the greatest rotational forces exerted on the structure are coming from wind, not from water, and these would result in low-frequency motions that could be countered by the already rotating nacelle. The smooth spar structure means that surface waves and currents don't result in huge moments about vertical.
Without some kind of active balance, it'll still tip to some degree. I wonder if there's much to be gained by tilting the 'keel' forwards to keep the mast vertical?
In case you're interested, this[1] document is of great interest if you wish to understand how these offshore turbines perform empirically. I'll give you a hint: not very good. Any piece of machinery exposed to sea salt doesn't last long. Also maintenance will be a big problem: just think one second the kind of undertaking needed to send a team of technicians to repair only one of these turbines. Let's not talk about replacing any large piece.
Statoil has done offshore drilling since the 70s, the people who work there probably know more than anyone else in the world about designing and operating very large machinery at sea. You can read more on their web pages or search the web for statoil to find examples of what i mean.
yep, but a wind turbine is churning way less money than an oil rig, you get the chopper only for extreme cases (and it's a pain because of the rotor, sometime they just use the emergency lift to get into the water with a life raft).
So now we are talking high sea docking to a moving structure in the North Sea, not going to happen in the winter. So any incident and you lose your entire season, and now you're in a downward spiral. I'm not saying this won't work, I'm saying it's a very complicated situation.
I think they have thought about it, it doesn't mean they got it right. Those people deliver brand new wind turbines whose rotor are not balanced. They deliver onshore turbine bolted to deficient foundations. They never reach their goals. (Yes I have worked a bit in the industry)
>They deliver onshore turbine bolted to deficient foundations. They never reach their goals. (Yes I have worked a bit in the industry)
As someone who presumably works a bit more than you in the offshore construction industry, I'd love to see you quantify these statements. Especially since you imply them to be industry-wide, commonplace blights.
Instead of picking a fight (I already know no source or figure would satisfy you), would be constructive and explain how the yaw works on floating systems?
>(I already know no source or figure would satisfy you)
Woah there. I'm not picking a fight with you. You make some pretty bold claims like "they deliver insufficient foundations." Tolerances for verticality, foundation position, etc. are contractually obliged and delivered overwhelmingly with success.
>would be constructive and explain how the yaw works on floating systems?
"Floating systems" is too broadly undefined to give you an answer. Could be that the mooring design resists yaw motion within certain tolerances. Could be that yaw motion of the base is compensated by a rotating nacelle.
> I think they have thought about it, it doesn't mean they got it right.
I think you're being evasive.
Do you think they have not thought about these problems as much or as effectively as you have?
How much have you thought about it, what expertise are you comparing to this company's proposals, and how do your proof of concept deployments compare to theirs in terms of size, scale, and longevity?
Exactly that. The difference to other offshore is not that it's further away from the coast, just that it can be used for less shallow areas. They should still be reachable within a day by boat and I guess maintenance shouldn't differ much from other offshore wind farms.
Yes, the marine environment is harsh. Corrosion is an issue. Maintenance is challenging. But these are not new problems: these are solvable (and solved) engineering challenges. The O&G industry has considerable overlap with offshore wind; foundation design, transportation and installation, etc., all well-understood and in practice for literally decades.
I haven't read the report you cited, but it is already 5 years old (much has changed in the past decade). The wind farm performance degredation they speak of in Denmark and the UK might have a lot to do with outdated technology of these older turbines. The first offshore farm in Denmark was built in 1991. Technologies since even 2010 have greatly improved.
I know deterioration of the solar panels is a concern for land-based installations. I imagine that could be accelerated by sea salt, waves, and storms.
I'm also curious how cloudy/foggy ocean sites are compared to ideal desert-based land sites like Nevada. That also might be a factor.
I think wind makes more sense at sea than solar. It can operate 24x7 if things stay breezey. In these chosen locations, that is indeed most of the time, and what sets them apart from most land-based locations.
Going to the expense of making a large offshore solar farm which is useless for half the day doesn't seem like as good an investment, even if all the other technical and weather issues were OK.
There's a page with German electricity production by source [1]. According to that, wind is still more reliable than solar but even offshore wind seems to be far from 24x7. It looks like yesterday there was virtually no wind on the North Sea. It still makes most sense to combine both and then use batteries to match production with demand. Relying on one source won't work.
there is no shortage of space on roofs for solar panels. Wind turbines need a special place, far from houses, and have an acceptance by the population problem.
Panels are nice and quiet, we have plenty of roofs, and don't kill birds or bats. Wind Farms are a bit noisy, kill birds and bats, and have one heck of a bad failure condition if you've ever had the misfortune to be near one when things go bad. Also, the wind farms that don't float seem to make much better fishing spots, so bonus.
Also, the conditions at sea make me think that wind farms would have a bit of advantage. It would seem that during conditions that require the greatest energy to stabilize that wind has more power than solar.
I read that painting windmills white attracts insects, which attracts their predators. I'm hoping someone's experimenting with various colors. Maybe reduce the mortality.
[Volunteered at Audubon for a decade. Love birds. Also hope this windmill thing works out.]
Flying fish. A report by the Koch Brothers Environmental Preservation Institute says floating wind turbines would kill at least a hundred trillion of them a day, and crash the entire ocean ecosystem.
There's still quite a lot of space for solar panels on land.
Among the benefits of offshoring wind turbines is generally higher and more consistent wind speeds offshore, less nuisance due to noise, and the ability to construct larger, more effective turbines than is possible on land.
For solar, there's not necessarily more or better sunshine offshore. There's no reason an offshore solar panel would be fundamentally different from an onshore one. And due to the much harsher environment, much of the difference between the two would relate to corrosion protection and reliability (adding to its cost).
For offshore solar you'd have the complexity and cost of offshore installation and maintenance, without the clear benefit of better sun offshore. That's a hard pill to swallow when there's so much potential to have solar panels on land.
I'm curious if they generate enough energy that they could do autonomous station keeping with thrusters in the base.
What is hard to appreciate is the scale of these things, they are like 50% larger than the largest land based wind turbine. That is pretty amazingly huge. And I'm not sure how you do maintenance on one but they do look pretty amazing.
> I'm curious if they generate enough energy that they could do autonomous station keeping with thrusters in the base.
I cannot help but think during conditions where station keeping is really needed that the wind power would be at its highest, so it should be enough given the design of what is where.
>autonomous station keeping with thrusters in the base.
This adds far more complexity and risk than you might expect. Redundancy, reliability, etc. all are vitally important.
If one of several thrusters fails, and the environmental conditions are too great for the remaining thrusters to match, what happens?
How do you maintain the thrusters? You could have station-keeping with tugs during maintenance, but often maintenance of azimuthing thrusters requires a drydock.
Hypothetically speaking, if all the turbines were somewhat easily mobile, their position could be optimized for the given wind conditions. That could be pretty interesting! Today however that's science fiction.
Furthermore, there's always going to be a subsea tether for power. That's unavoidable.
In any case, moorings of various types are dumb, well-understood, and very effective.
Wrt to reliability of thrusters - this is pretty well covered. They have been drilling for oil with unmoored platforms for decades. Here, the requirements for keeping the rig in a fixed position are quite loose compared to a drilling rig.
The power tether would be quite minimal. Also, there is the possibility of creating untethered rigs that store hydrogen locally. Probably not feasible atm.
These are also manned platforms, having crews and stand-by support vessels to engage in the event something goes wrong.
It's also just one vessel with multiple thrusters, not dozens.
>Here, the requirements for keeping the rig in a fixed position are quite loose compared to a drilling rig.
Good point- the allowable excursions would probably be much greater than for a drilling rig.
>The power tether would be quite minimal.
Doable, for sure; minimal, I don't quite agree. It's still a complex system. And there's still probably going to be a transmission module for the shore cable.
>Also, there is the possibility of creating untethered rigs that store hydrogen locally. Probably not feasible atm.
Love the layout, and the video production, in terms of clearly presenting salient information. Even where they show diameter with lots of pointer lines towards radius-of-one-blade (and a bit of another).
Nit-picking -- exclusive use of upper case overlays may look hip, but reduces clarity. M/S means either miles or mega-somethings per something. Whereas m/s means metres (only Americans spell them meters for reasons that aren't clear) per second.
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[ 2.4 ms ] story [ 201 ms ] threadI wish more startups, or any large project in general, had this type of site.
So the question is rather is it economically viable?
Subsidy free traditional offshore wind is happening, but this requires good site conditions for installation, cracking subsidy free floating wind would open up much larger spaces of ocean to development and thus more power and profit! Win win!
http://ideol-offshore.com/en
http://www.nauticawindpower.com/
https://composites.umaine.edu/research/deepcwind-consortium/
http://dwwind.com/press/deepwater-wind-develop-west-coasts-f...
http://www.bluehengineering.com/tablet/index.html
http://www.tridentwinds.com/
http://www.hexicon.eu/
I'm sure there are many more.
People who have to pay for oil and everything it helps us create/transport (basically everything) are forced to pay for this, thanks to eco-terrorists, while tried and tested nuclear power will last us thousands of years.
Unlike nuclear and coal, this will harm the aquatic life and birds more... but those things only matter when you are speaking against their narrative.
And as a result there have been issues with them killing lots of birds, esp 1) IIRC large predatory birds which are looking down at the ground for prey and can't change course as easily as a small bird, and 2) being in migration paths. But I think both of those problems are pretty well understood by now and I'm guessing this project takes both into account.
You apparently haven’t seen modern (ie installed in the last 5 years, this stuff moves quickly) wind turbines. They are huge and slow turning, also much quieter than the smaller, shorter, faster spinning ones.
Unless I'm miscalculating, that means that the tip of one of the rotors will travel 515 metres per revolution, which at 4.8-12.1rpm is a tip speed of between 2,472 metres per minute and 6,231 metres per minute.
To put that in more common units, that's between 148km/h and 373km/h.
[1] https://stateofgreen.com/en/profiles/vestas/solutions/v164-8...
Second benefit of larger turbines is much more of the swept area is outside of the normal flight heights of birds. Either too low for migration patterns or too high for most hunting and scooting flight heights (relative to nearest surface).
So one 8MW turbine is likely to kill a lot less than 8 * 1 MW and much, much less than 80 * 100kw, even if it has a much larger swept area.
Now as these are offshore turbines, and Hywind, being for quite deep water. Likely to be far offshore, there are not that many birds around too get hit in the first place.
The nice thing about the slower RPMs compared to smaller tubines (especially pre 2000's) is that slower RPM's make it easier to spot the turbine for birds. High RPM's give optical effects that make it hard to predict where something is going (e.g. wheel looks like rotating backwards etc...) so bigger is easier too avoid for birds.
[1] http://www.audubon.org/news/will-wind-turbines-ever-be-safe-...
After accounting for initial setup costs and maintenance of wind turbines (it is worse than Solar in this regard because of the wear and tear in mechanical parts) and power infrastructure (which has to be designed to handle such variation without any impact on consumers), it will take a very long time to break even, if at all. And don't forget that we will still need something reliable like nuclear or fossil fuels to back it up... which we already have enough of to last for thousands of years.
So, basically, all we get with wind is more work for no gain at all (not to mention the unnecessary environmental harm). I am sure Statoil is not ignorant of this. They are just using a small portion of their 100 billion dollar yearly revenue in this to please the eco-terrorists.
As pointed out elsewhere in the thread: indeed the RPM can be low, but the rotor tip velocity is high.
The blades go very fast at the outer part of the blade. It will easily kills birds.
I also think you simplifying nuclear power. You still need to store the waste and it something quite a few people dislike. And no body is investing in Thorium R&D, at least not in USA.
> aquatic life and birds more
There are several country side plastic patches in the ocean which is cause cause of oil products that cannot biodegrade in a reasonable time.
The global warming cause by oil which in turn cause bleaching, killing aquatic life, causing far more damage than whatever you think wind turbines are causing.
Airplane and free roaming cats kill more birds than wind turbines. I know turbines do kill birds but they can move it away from migration paths.
Right wing of where exactly? I am not American but I am assuming you're talking about the US. In that case, you should know that the clean tech industry in the US started and thrived during Bush presidency. The mainstream American right wingers are no less brainwashed than the American left wingers when it comes to renewables and climate change. Climate change deniers are a minority that even Trump disassociates himself from because he knows majority of the right would hate him for it.
>And no body is investing in Thorium R&D, at least not in USA.
People would invest in it if they thought it would work. It's like Solar and Wind, which are complete waste of money, except it is not "renewable" and hence not even cool.
>I know turbines do kill birds but they can move it away from migration paths.
As I already said, I know that it is okay as long as it fits the narrative.
- Statoil took over Hywind in 2008 when they acquired the O&G division of Hydro, and set up the first test turbine in 2009
- Shell is also active in offshore wind, so this is not limited to majority state owned companies
Offshore wind could be competitive in the early 2020's without subsidies, depending on your assumption of fossil fuel and CO2 prices
Bottom line: Floating offshore wind could be very promising in areas with deep water, such as Japan, so I would not call this busy work
http://offshorewind2017.com/files/media-and-press/Offshore-W...
https://www.nytimes.com/2017/04/14/business/energy-environme...
They are subject to final investment decision in 2020/21, so could be scrapped if commodity and CO2 prices don't move favorably
https://cleantechnica.com/2016/09/15/wind-energy-costs-set-c...
I work in IT, not offshore. My claims are based on living in Norway and reading about Statoil almost daily, and talking to people I know working in offshore, and on IT projects at Statoil. It is hard to find hard evidence for claims about Statoil. The closest thing i can find to evidence is to tell you to just check the headlines on some random Norwegian newspaper. This one is on the front page today: http://e24.no/energi/oljeinvesteringer/frykter-slutten-paa-s... one of the things stated there which could be relevant is that one project scheduled for completion in 2022 has had its construction costs cut in half from 100 billion NOK to 50 billion. Some would say this is evidence of Statoil being able to rationalize well. I would say this is evidence of Statoil having a history of over-spending. It all depends on your point of view, it is next to impossible to get the full picture.
"its priorities"
On the other hand, if you compare the risk of getting stranded to a big nuclear plant, it probably looks a lot better in comparison.
UK wind strike prices are now below the strike price negotiated for Hinckley Point C.
http://www.sciencedirect.com/science/article/pii/S0167610515...
Its catenary mooring system resists rotation of the turbine hull. How much so, I can't say.
I suspect that by far the greatest rotational forces exerted on the structure are coming from wind, not from water, and these would result in low-frequency motions that could be countered by the already rotating nacelle. The smooth spar structure means that surface waves and currents don't result in huge moments about vertical.
[1] http://www.ref.org.uk/attachments/article/280/ref.hughes.19.... (see Figure 1, page 13, "Performance degradation due to age using equal weights")
[1] http://www.ewea.org/blog/2012/12/study-on-turbine-lifespan-j...
So now we are talking high sea docking to a moving structure in the North Sea, not going to happen in the winter. So any incident and you lose your entire season, and now you're in a downward spiral. I'm not saying this won't work, I'm saying it's a very complicated situation.
As someone who presumably works a bit more than you in the offshore construction industry, I'd love to see you quantify these statements. Especially since you imply them to be industry-wide, commonplace blights.
Woah there. I'm not picking a fight with you. You make some pretty bold claims like "they deliver insufficient foundations." Tolerances for verticality, foundation position, etc. are contractually obliged and delivered overwhelmingly with success.
>would be constructive and explain how the yaw works on floating systems?
"Floating systems" is too broadly undefined to give you an answer. Could be that the mooring design resists yaw motion within certain tolerances. Could be that yaw motion of the base is compensated by a rotating nacelle.
I think you're being evasive.
Do you think they have not thought about these problems as much or as effectively as you have?
How much have you thought about it, what expertise are you comparing to this company's proposals, and how do your proof of concept deployments compare to theirs in terms of size, scale, and longevity?
Yes, the marine environment is harsh. Corrosion is an issue. Maintenance is challenging. But these are not new problems: these are solvable (and solved) engineering challenges. The O&G industry has considerable overlap with offshore wind; foundation design, transportation and installation, etc., all well-understood and in practice for literally decades.
I haven't read the report you cited, but it is already 5 years old (much has changed in the past decade). The wind farm performance degredation they speak of in Denmark and the UK might have a lot to do with outdated technology of these older turbines. The first offshore farm in Denmark was built in 1991. Technologies since even 2010 have greatly improved.
Bio-fouling and corrosion are still huge problems though.
I'm also curious how cloudy/foggy ocean sites are compared to ideal desert-based land sites like Nevada. That also might be a factor.
Going to the expense of making a large offshore solar farm which is useless for half the day doesn't seem like as good an investment, even if all the other technical and weather issues were OK.
[1] https://www.energy-charts.de/power.htm?source=solar-wind&wee...
And then you have to protect your project from salt water and the waves.
The waves are especially tough, because rogue waves can create pressures of 100 tons per square meter.
https://en.wikipedia.org/wiki/Rogue_wave
Also, the conditions at sea make me think that wind farms would have a bit of advantage. It would seem that during conditions that require the greatest energy to stabilize that wind has more power than solar.
[Volunteered at Audubon for a decade. Love birds. Also hope this windmill thing works out.]
Among the benefits of offshoring wind turbines is generally higher and more consistent wind speeds offshore, less nuisance due to noise, and the ability to construct larger, more effective turbines than is possible on land.
For solar, there's not necessarily more or better sunshine offshore. There's no reason an offshore solar panel would be fundamentally different from an onshore one. And due to the much harsher environment, much of the difference between the two would relate to corrosion protection and reliability (adding to its cost).
For offshore solar you'd have the complexity and cost of offshore installation and maintenance, without the clear benefit of better sun offshore. That's a hard pill to swallow when there's so much potential to have solar panels on land.
What is hard to appreciate is the scale of these things, they are like 50% larger than the largest land based wind turbine. That is pretty amazingly huge. And I'm not sure how you do maintenance on one but they do look pretty amazing.
I cannot help but think during conditions where station keeping is really needed that the wind power would be at its highest, so it should be enough given the design of what is where.
Knowing nothing about anything, my first thought was the RP FLIP.
https://en.wikipedia.org/wiki/RP_FLIP
This adds far more complexity and risk than you might expect. Redundancy, reliability, etc. all are vitally important.
If one of several thrusters fails, and the environmental conditions are too great for the remaining thrusters to match, what happens?
How do you maintain the thrusters? You could have station-keeping with tugs during maintenance, but often maintenance of azimuthing thrusters requires a drydock.
Hypothetically speaking, if all the turbines were somewhat easily mobile, their position could be optimized for the given wind conditions. That could be pretty interesting! Today however that's science fiction.
Furthermore, there's always going to be a subsea tether for power. That's unavoidable.
In any case, moorings of various types are dumb, well-understood, and very effective.
The power tether would be quite minimal. Also, there is the possibility of creating untethered rigs that store hydrogen locally. Probably not feasible atm.
Indeed, but this is still a rather different scenario.
Drilling platforms engaged in drilling while under dynamic positioning are doing so under a quite reliable and robus classification, DP3.
https://en.wikipedia.org/wiki/Dynamic_positioning#Class_requ...
These are also manned platforms, having crews and stand-by support vessels to engage in the event something goes wrong.
It's also just one vessel with multiple thrusters, not dozens.
>Here, the requirements for keeping the rig in a fixed position are quite loose compared to a drilling rig.
Good point- the allowable excursions would probably be much greater than for a drilling rig.
>The power tether would be quite minimal.
Doable, for sure; minimal, I don't quite agree. It's still a complex system. And there's still probably going to be a transmission module for the shore cable.
>Also, there is the possibility of creating untethered rigs that store hydrogen locally. Probably not feasible atm.
Could be very interesting!
Nit-picking -- exclusive use of upper case overlays may look hip, but reduces clarity. M/S means either miles or mega-somethings per something. Whereas m/s means metres (only Americans spell them meters for reasons that aren't clear) per second.