• Visitors can check out the Forum FAQ by clicking this link. You have to register before you can post: click the REGISTER link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. View our Forum Privacy Policy.
  • Want to receive the latest contracting news and advice straight to your inbox? Sign up to the ContractorUK newsletter here. Every sign up will also be entered into a draw to WIN £100 Amazon vouchers!
Collapse

You are not logged in or you do not have permission to access this page. This could be due to one of several reasons:

  • You are not logged in. If you are already registered, fill in the form below to log in, or follow the "Sign Up" link to register a new account.
  • You may not have sufficient privileges to access this page. Are you trying to edit someone else's post, access administrative features or some other privileged system?
  • If you are trying to post, the administrator may have disabled your account, or it may be awaiting activation.

Previously on "Not too windy today"

Collapse

  • Diver
    replied
    Originally posted by TimberWolf View Post
    At the risk of straying into the field of meteorology, why? I vaguely get the impression land messes winds up, perhaps making them gusty etc, but know little about offshore winds. Except maybe that in hot countries they often blow inshore during the day and offshore at night, and a few other odds and ends.
    Meteorology is not my field so do what I do and google

    Leave a comment:


  • TimberWolf
    replied
    Originally posted by Diver View Post
    Wind offshore in the selected locations is historically more consistant and more constant the further offshore.
    At the risk of straying into the field of meteorology, why? I vaguely get the impression land messes winds up, perhaps making them gusty etc, but know little about offshore winds. Except maybe that in hot countries they often blow inshore during the day and offshore at night, and a few other odds and ends.

    Leave a comment:


  • Diver
    replied
    Originally posted by TimberWolf View Post
    Predicable, as is being able to be predict the wind speed [some hours or days] ahead of time, or predictable in the sense of being fairly constant, or dependable?

    Assuming the former, why is offshore wind more predicable than onshore wind?
    Wind offshore in the selected locations is historically more consistant and more constant the further offshore.

    Leave a comment:


  • TimberWolf
    replied
    Originally posted by Diver View Post
    Lets be honest here, the wind farms are going to be built offshore, they have to be because we need the energy and the onshore turbines are too inneficient and unpredictable with regard to forecasted availibility at present.
    Predicable, as is being able to be predict the wind speed [some hours or days] ahead of time, or predictable in the sense of being fairly constant, or dependable?

    Assuming the former, why is offshore wind more predicable than onshore wind?

    Leave a comment:


  • Diver
    replied
    Finally a solution to the countries power supply problem

    No more Co2 and smoke belching fossil fuel fired power stations.
    That should keep the Greens Happy
    No more radioactive waste producing power stations.
    That should keep the tree huggers and locals happy
    No more Onshore Wind turbines
    That should keep the middle class and hikers happy
    No more Offshore wind Turbines
    No more tidal turbines
    That should keep the fishermen happy
    No more wave energy converters
    That should keep the fishing fraternity, paddlers and beachcombers happy
    No more Solar Arrays
    That should keep the "Save our scenery" crowd happy

    We are going to produce electrical energy using "Magic"

    Yes you heard right!

    We have enlisted the aid of Sir Paul Daniels to head up this amazing new avenue of research.

    Unfortunately there will be a slight burden on the public purse in the form of subsidies.


    Watch this space for project updates > placeholder <
    Last edited by Diver; 30 May 2012, 18:15.

    Leave a comment:


  • Diver
    replied
    Originally posted by EternalOptimist View Post
    Spain cut subsidies to wind, now the industry is finished

    according to this Bloomberg article, the Spainish wind industry is doomed.

    appears that sustainable energy, means 'we can produce energy . provided we are supported by the taxpayer'
    Wind, wave & tidal power at one tenth the real cost to the taxpayer that O&G, coal & Nuclear is.

    But who cares as long as I have a job for life, excellent salary, and a huge bonus coming out in 3 week time

    Lets be honest here, the wind farms are going to be built offshore, they have to be because we need the energy and the onshore turbines are too inneficient and unpredictable with regard to forecasted availibility at present.
    We are also going to need nuclear power stations despite the exhorbitant cost of building and decommissioning them, and the £3.2 billion + that it is going to cost to manage the radioactive waste for longer than anyone alive today will live (~1000 years)
    We are going to continue to invest in AND subsidise every available source of power because we have to.
    No matter what any of the Anti's or other numpties criticising the various technologies and policies says. this is going to happen, unless of course any of the loudmouthed wittless cynics has a workable solution that is not going to lead to rolling blackouts after 2017 when our existing power stations start to shut down.
    almost 60% of our existing power supply, both coal and nuclear will be gone by 2019. I'm not worried, I have alternative power in the form of Solar and a backup automatic 7 kw generator for when the rolling blackouts start.

    I love the way people whine and moan that "somebody else" isnt doing something about it.
    I'd love to see a total ban on personal electrical equipment other than a radio and a refrigerator. People would be begging for any form of power supply. no matter the cost, even in lives.
    I find those of little foresight and intelligence quite annoying. I know I should merely pitty the fools but I find the annoying little ankle biters quite irritating . particularly when grownups are trying to sort out the mess left by the children and the ever expanding pool of even more nupties and fckwits being bred to drain the remaining limited resources that we have left. and the new breed will probably whine even more about those trying to keep them supplied from even smaller resources.
    Last edited by Diver; 30 May 2012, 17:57.

    Leave a comment:


  • EternalOptimist
    replied
    Spain cut subsidies to wind, now the industry is finished

    according to this Bloomberg article, the Spainish wind industry is doomed.

    appears that sustainable energy, means 'we can produce energy . provided we are supported by the taxpayer'

    Leave a comment:


  • EternalOptimist
    replied
    Originally posted by TimberWolf View Post
    How can people think wind turbine are ugly anyway, they are like big moving trees. If I had one near me I would probably end up watching it all the time, but as it is I have to look at the ones about a mile away and they won't let me get near them.


    why not go and look at a big moving tree instead

    Leave a comment:


  • SupremeSpod
    replied
    Originally posted by TimberWolf View Post
    How can people think wind turbine are ugly anyway, they are like big moving trees. If I had one near me I would probably end up watching it all the time, but as it is I have to look at the ones about a mile away and they won't let me get near them.
    Probably for the best, you'd only end up losing a finger/your hand/arm - delete as appropriate...

    Leave a comment:


  • TimberWolf
    replied
    How can people think wind turbine are ugly anyway, they are like big moving trees. If I had one near me I would probably end up watching it all the time, but as it is I have to look at the ones about a mile away and they won't let me get near them.

    Leave a comment:


  • d000hg
    replied
    Yes but I'd say making fossil fuel stations more flexible allows us to use nonrenewable sources more effectively... use wind when it's windy, use sun when it's sunny, burn stuff when it's not.

    Leave a comment:


  • EternalOptimist
    replied
    Originally posted by d000hg View Post
    That makes it seem like a hell of a lot... you could cover most of Central London deeper than head-height. From a single day's usage!

    So as I said, rather than concluding that non-constant power generation is pointless, how about looking at improving conventional generators. Are they that way due to irrevocable laws, or simply because people 'know' that it's a problem which can't be solved? I would tend to imagine the latter - that applying modern science to something as 'dumb' as burning coal could lead to good things.

    You only have to look at the internal combustion engine to see high fuel prices are driving new innovations at a high rate.
    Now you are catching on.
    Instead of spending billions upon billions in a futile attempt to mitigate a trace gas which is plant food, why not spend it on developing something that has real value


    Leave a comment:


  • d000hg
    replied
    Originally posted by TimberWolf View Post
    Those large volumes are easier to visualise if you turn the m^3 into a single cube. Take the cube root of 10^7 = 464m * 464m * 464m = a cube half a kilometre on its side.
    That makes it seem like a hell of a lot... you could cover most of Central London deeper than head-height. From a single day's usage!

    Originally posted by EternalOptimist View Post
    what he says ^

    what he means > The wind can go from zero to max and back down again very quickly.

    That means that the conventional generators must be able to be switched off and on very quickly, which they cannot. Therefore either the conventional generators must be left to idle
    or the windmills must be left to idle
    So as I said, rather than concluding that non-constant power generation is pointless, how about looking at improving conventional generators. Are they that way due to irrevocable laws, or simply because people 'know' that it's a problem which can't be solved? I would tend to imagine the latter - that applying modern science to something as 'dumb' as burning coal could lead to good things.

    You only have to look at the internal combustion engine to see high fuel prices are driving new innovations at a high rate.

    Leave a comment:


  • TimberWolf
    replied
    Originally posted by Diver View Post
    The national grid is currently limiting connection as the grid infrastructure need a complete overhaul.
    The generation industry is currently looking a the supergrid option rather than a local (UK) one.

    I do not know what the situation is with onshore wind farms as I only deal with offshore renewables and know little about the small turbines used on shore. I do know that they are significanly smaller and less efficient than those we are currently installing offshore. and the further we get from shore the more efficient we become.

    The wind power density (the mean density of the wind’s kinetic energy, over the year) at the close to shore wind farm Kentish Flats is about 713 W per square metre of vertical plane, at 80 metres above sea level. The Vestas 3 MW turbines there have a net efficiency of approximately 30%, for that wind profile: i.e. 30% of the wind’s kinetic energy is converted to electricity; (so in this case the figure is efficiency, rather than capacity factor). The turbines have a swept diameter of 90 metres, and thus a swept area of 6360 m2 (45 m x 45 m x pi). So the power generated is:
    713 W/m2 x 6360 m2 x 30% = 1.36 MWe per turbine.
    The turbines are spaced in a 700 m x 700 m grid, so the turbine density is
    1/(0.7×0.7) = 2.06 turbines per square km of seabed,
    giving a density of harvested electricity of 2.8 MWe/km2, at 100% availability. A 90% availability gives around 2.5 MWe/km2.
    And now to generalise to British waters, grouping the depths into shallow, medium and deep waters: 0-25 m, 25-50 m, and 50-700 m.
    80 GW in shallow waters (0-25 m)
    In the (territorial + EEZ) waters around Britain & Northern Ireland, there’s roughly 40 000 km2 of seabed shallower than 25 m, with a wind power density of 579 W/m2 (that’s per square metre in the vertical plane: the area that the turbine blades sweep through). So, for the depths of 0-25 m, scaling the Kentish Flats figure accordingly, the mean potential electricity density is:
    2.5 MWe/km2 x 579/713 = 2 MWe/km2
    40 000 km2 x 2 MWe/km2 = 80 GWe at 0-25m depths
    270 GW in seas of depth 25-50m
    For the 90 000 km2 of British waters in depths of 25-50 m, the wind power density is 868 W/m2(vertical). giving mean potential electricity of:
    2.5 MWe/km2 x 868/713 = 3 MWe/km2
    90 000 km2 x 3 MWe/km2 = 270 GWe at 25-50m depths
    790GW in deeper waters 50-100m
    And then there’s about 210 000 km2 at 50m-100m, with a wind power density of 1070 W/m2(vertical)
    2.5 MWe/km2 x 1070/713 = 3.75 MWe/km2
    210 000 km2 x 3.75 MWe/km2 = 790 GWe at 50-100m depths

    London Array turbines for Phase One will have a capacity of 3.6MW each. They’ll be fitted with Siemens’ new 120m rotor. Each turbine will have a hub height of 87m above sea level. The turbines will each have three blades.
    Dogger bank will be 50 miles off shore and be installed with ~6mw turbines in an area that has almost constant usable wind velocities.
    My guess would have been that your 20%-38% capacity figure was a projection rather than current status. With current wind capacity at more like 10% of total electrical consumption in the UK (Circa 60 GW I believe).

    Leave a comment:


  • Diver
    replied
    Originally posted by EternalOptimist View Post
    what he says ^

    what he means > The wind can go from zero to max and back down again very quickly.

    That means that the conventional generators must be able to be switched off and on very quickly, which they cannot. Therefore either the conventional generators must be left to idle
    or the windmills must be left to idle


    madness. economics of the madhouse


    But this scenario decreases with the spread of turbines offshore where the wind is more constant, development of the grid, regulating or smoothing out the feed-in.
    and as we develop better wave & tidal energy converters the use of wind and traditional power stations will drop off.
    With a super grid across europe, we should be able to sell our excess rather than idle our plant or store energy.

    Leave a comment:

Working...
X