NickW + 2,714 NW March 19, 2019 9 minutes ago, Wastral said: Bravo... dirt cheap small boats are now "dual use" in your brand new engineering experience eh... Its the cranes/barges and workers that are the $$$, not the stupid twink twank boats which move people and goods in green water. Not that it matters, tidal can happen almost nowhere other than a few rare spots. Couple of those spots are quite adequate if one can run the power lines. They are all far far north far far away from populations. cranes and barges are used quite a bit in wind farm developments....... Dogger Bank is 100km off the UK coast and about 200km from the UK central belt of population - Sheffield, Leeds, Hull etc Quote Share this post Link to post Share on other sites
footeab@yahoo.com + 2,187 March 19, 2019 1 minute ago, NickW said: cranes and barges are used quite a bit in wind farm developments....... Dogger Bank is 100km off the UK coast and about 200km from the UK central belt of population - Sheffield, Leeds, Hull etc Yup, bravo, exceptions do not make the rule. You love your exceptions. The rest of 99.9% of humanity will live in the real world. Quote Share this post Link to post Share on other sites
NickW + 2,714 NW March 19, 2019 1 minute ago, Wastral said: Yup, bravo, exceptions do not make the rule. You love your exceptions. The rest of 99.9% of humanity will live in the real world. Dogger bank alone will host 7-8GW of wind power. The rest of the North Sea is fairly close to large populations of Northern Europe. Lets take a little trip from the land of Elves and Fairies and look at Planet Earth and in particular areas with good wind resources, shallow sea bed and nearby populations. East China Sea The Baltic NE Atlantic Seaboard 1 Quote Share this post Link to post Share on other sites
footeab@yahoo.com + 2,187 March 19, 2019 4 minutes ago, NickW said: Dogger bank alone will host 7-8GW of wind power. The rest of the North Sea is fairly close to large populations of Northern Europe. Lets take a little trip from the land of Elves and Fairies and look at Planet Earth and in particular areas with good wind resources, shallow sea bed and nearby populations. East China Sea The Baltic NE Atlantic Seaboar ... Subject was offshore industry applicable to... which they are not as the cranes etc are on massive offshore platforms useless for.... Quote Share this post Link to post Share on other sites
Lionel Mills + 1 March 19, 2019 2 hours ago, Wastral said: --------------------------------- reply to Lionel PS: There are many places where there is always flow and is never stagnant. Of course harnessing it is near impossible. PPS: If covered in Niobium, no cleaning needed... Of course its price is the same as silver... PPPS: Hydrofoil roughness is not a big deal as water is incompressible. Not good of course, but not the end of the world either. PPPPPS: Water flow around.... Uh, no more than air flows around wind turbines to avoid them 🤔 You shoot down your own ps and pps, but as regards `Hydrofoil roughness is not a big deal', you are clearly not a sailing man or if you are, you will always be slower than people who polish their foils. Yes some of the air does flow around wind turbines to avoid them i.e. the incoming air `senses' the pressure build up ahead of the turbine and is deflected because it always flows `downhill' which in this case leads round rather than through the swept disc. The same is true of water in tidal power. The water is only flowing in response to a pressure gradient and this gradient is affected up-flow i.e.before the water reaches the turbine. The net effect is a slower flow through the turbine than is present beside it and/or before it was installed. Quote Share this post Link to post Share on other sites
footeab@yahoo.com + 2,187 March 19, 2019 1 hour ago, Lionel Mills said: You shoot down your own ps and pps, but as regards `Hydrofoil roughness is not a big deal', you are clearly not a sailing man or if you are, you will always be slower than people who polish their foils. Yes some of the air does flow around wind turbines to avoid them i.e. the incoming air `senses' the pressure build up ahead of the turbine and is deflected because it always flows `downhill' which in this case leads round rather than through the swept disc. The same is true of water in tidal power. The water is only flowing in response to a pressure gradient and this gradient is affected up-flow i.e.before the water reaches the turbine. The net effect is a slower flow through the turbine than is present beside it and/or before it was installed. HOW did I shoot down myself? Hrmm? .... wonders if you even know what Niobium is... You would not use 100%... same way you use copper coat. of course everyone has gone to silicone.... Then there are robotic cleaners that would need to be developed for a simple scrubbing. By the way: a real racer, if they can read a roughness chart for friction NEVER polishes their hydrofoils or their boat hull. This increases skin drag. You want a less than polished surface. (we are assuming below cavitation) Above cavitation, highly polished, mirror finish is required. Turbines obviously work BELOW cavitation. Quote Share this post Link to post Share on other sites
Rasmus Jorgensen + 1,169 RJ March 19, 2019 5 hours ago, Wastral said: Just curious... What the heck do offshore vessels have to do with US shale and Tidal energy? Curious minds want to know. Everything! The world only consumes so much oil. And shale is essentially marginal offshores main competitor. when all the CAPEX flows to shale then O&G vessels has to find something else to do. ps. there is a lot of cross over between particular offshore and oil and gas supply chains. Your above observations are not correct. 1 Quote Share this post Link to post Share on other sites
NickW + 2,714 NW March 19, 2019 (edited) 21 hours ago, Lionel Mills said: You shoot down your own ps and pps, but as regards `Hydrofoil roughness is not a big deal', you are clearly not a sailing man or if you are, you will always be slower than people who polish their foils. Yes some of the air does flow around wind turbines to avoid them i.e. the incoming air `senses' the pressure build up ahead of the turbine and is deflected because it always flows `downhill' which in this case leads round rather than through the swept disc. The same is true of water in tidal power. The water is only flowing in response to a pressure gradient and this gradient is affected up-flow i.e.before the water reaches the turbine. The net effect is a slower flow through the turbine than is present beside it and/or before it was installed. I assume water behaves similarly as air. With wind turbines the theoretical maximum energy the turbine can capture from the air stream is 59% otherwise the air the other side of the turbine would simply stop. https://en.wikipedia.org/wiki/Betz's_law Edited March 20, 2019 by NickW 1 Quote Share this post Link to post Share on other sites
footeab@yahoo.com + 2,187 March 19, 2019 2 hours ago, NickW said: I assume a water behaves similarly as air. With wind turns the theoretical maximum energy the turbine can capture from the air stream is 59% otherwise the air the other side of the turbine would simply stop. https://en.wikipedia.org/wiki/Betz's_law Well yes Betz's law holds. Doesn't have anything to do with what I said. Quote Share this post Link to post Share on other sites
footeab@yahoo.com + 2,187 March 19, 2019 5 hours ago, Rasmus Jorgensen said: Everything! The world only consumes so much oil. And shale is essentially marginal offshores main competitor. when all the CAPEX flows to shale then O&G vessels has to find something else to do. ps. there is a lot of cross over between particular offshore and oil and gas supply chains. Your above observations are not correct. Name one thing other than a supply boat... The Money and infrastructure in offshore is in its giant platforms and the people to run them. How will this help turbine placement? That requires barges with cranes... Now some of the ONSHORE industry is cross pollinating who are looking for more work as their offshore business is drying up. Quote Share this post Link to post Share on other sites
Rasmus Jorgensen + 1,169 RJ March 20, 2019 9 hours ago, Wastral said: Name one thing other than a supply boat... The Money and infrastructure in offshore is in its giant platforms and the people to run them. How will this help turbine placement? That requires barges with cranes... Now some of the ONSHORE industry is cross pollinating who are looking for more work as their offshore business is drying up. stanislaw Yudin for one. The fact that you are even making above argument shows you are clueless. And this conversation is over for me. 1 Quote Share this post Link to post Share on other sites
NickW + 2,714 NW March 20, 2019 9 hours ago, Wastral said: Well yes Betz's law holds. Doesn't have anything to do with what I said. I was replying specifically to Lionels comments. Quote Share this post Link to post Share on other sites
Rasmus Jorgensen + 1,169 RJ March 20, 2019 @Wastral In case you do not know what "stanislaw Yudin" I will tell you : It is a heavy-lift ship, owned by oil services giant Subsea 7; that particular vessel has gotten most of its work from Windfarms the past couple of years. Another great example is that offshore heavylift specialist Heerema (that has made a fortune in Oil and Gas) are converting pipelay vessel Aegir to heavylift, mainly for offshore wind. https://ocean-energyresources.com/2019/02/04/conversion-aegir-nearly-completed/ So you have oil services companies like SS7 and Heerema diversifying into offshore.... I know that oil crusader @Tom Kirkman can confirm that SS7 and Heerema are heavyweigths in offshore oil & gas, just in case you do not believe me.. 1 Quote Share this post Link to post Share on other sites
Tom Kirkman + 8,860 March 20, 2019 16 minutes ago, Rasmus Jorgensen said: So you have oil services companies like SS7 and Heerema diversifying into offshore.... I know that oil crusader @Tom Kirkman can confirm that SS7 and Heerema are heavyweigths in offshore oil & gas, just in case you do not believe me.. Yep, confirmed. Although with oil prices back to reasonable levels again lately, I expect offshore oil & gas to rebound eventually, and get offshore marine outfits like Subsea 7 returning to offshore oil and gas. Quote Share this post Link to post Share on other sites
Rasmus Jorgensen + 1,169 RJ March 20, 2019 4 minutes ago, Tom Kirkman said: Yep, confirmed. Although with oil prices back to reasonable levels again lately, I expect offshore oil & gas to rebound eventually, and get offshore marine outfits like Subsea 7 returning to offshore oil and gas. I have to admit that I disagree. If you look at what drove offshore activity it wasn't mega project(s) it shallow and midwater marginal build out projects. These are completely dead courtesy of US shale. this means you now have an overdimensioned supply chain that needs to find something to do... the mega-projects will still be there and continue to be a main and important part of subsea contractors like SS7s business. It just won't be the Quote Share this post Link to post Share on other sites