London Array - offshore windfarm

Re: tidal power

It is perfectly true that the output from a tidal stream generator will be cyclical (but to a reasonably predictable pattern, unlike wind) and there will be times in the day when it will produce little or no output. But consider the combined output from a number of such generating arrays on different sites, each with it's own times of null output. As we all know, there is considerable variation in the time of slack water from place to place round the coast, and taking the output of enough geographically dispersed tidal generators should give a reasonably constant aggregate output in the short term. Longer term, output will of course vary with the springs / neaps cycle, but again it is all predictable in advance and output which can be reliably predicted can be sold ahead, i.e. actually delivering value for the electricity as well as the ROCs.

The wind proponents try to use a similar argument, i.e. that there will never be conditions when all wind turbines lack wind simultaneously. This is false, as has been demonstrated on a number of occasions when a cold weather anticyclone has covered the whole of the UK: maximum electricity demand and not a wind turbine moving.
 
Hi! Interesting! Apart from the sailing aspect of navigating amongst the wind-farms in the Thames Estuary - no one has explained to me how any wind-mill produces electricity when it's calm. So what's the point? As it's sometimes calm. Must be the 'grants'; that attract money-making big-business? (Money from the tax-payer?). As mentioned, you can't shut down base-load, because you need generating stations when it's calm. I guess. And when it goes calm, it takes a long time to flash a power station back up onto the grid. (Is this true?!) And apart from carbon foot-prints, on land wind-farms, have you seen the blight of the enormous access roads up the hills, and concrete needed...? No, I can't understand it. Apart from making money for big-business? In the short term?
Best wishes.
 
Re: London Array - offshore windfarm-HEP

Thats my concern... long sands is migrating north east....

Already Foulgers Gat was north east this year of where it was last year, and there was talk of moving the SWMs.... we went through and found it quite shallow when on course, but deeper if you stayed north of the channel...

So... inevitably, it'll be in the wrong place....

Equally, even with a 22m air clearance to the blades, thats quite close if you've got a big mast.... one of the boats we've looked at is 15m air draft..... too close for me anyway.....
 
Re: London Array - offshore windfarm-HEP

The whole thing is a waste of time and money, 10% of energy from renewable sources is not achievable, and the only way forward is to go back to nuclear generation. By far the most efficient and effective source with least environmental damage if managed properly.
 
Re: London Array - offshore windfarm-HEP

Extract from Hydrographic Office report

"1.4 Foulger’s Gat has a controlling depth of 8.3 metres, within the Port of London Authorities area of responsibility.
1.5 The greatest are of change is at the southern entrance to Foulger’s Gat, where the bank on the eastern side has migrated westwards. The remainder of the area remains broadly similar to that surveyed in 2002.
1.6 The 2002 survey considered that the survey frequency should be extended to 12 years provided Trinity Light House Service monitored Foulger’s Gat. This proposal has not been implemented.
1.7 There are plans to provide a route through the windfarm where it covers Foulger’s Gat.
Reasons for Continuing to Resurvey the Area
1.8 Sediment along the eastern side of Foulger’s Gat is particularly mobile and although a wide channel with depths of 3 metres or more is available, long term change may reduce depths in the channel or change its position.
1.9 The approach to Fisherman’s Gat is generally stable and requires surveying less frequently.
Recommendations
1.10 The survey frequency is established at 12 years with reduced limits.
1.11 Foulger’s Gat should continue to be surveyed every 3 years. The availability of windfarm surveys should be investigated prior to undertaking these surveys.
1.12 The 3 year survey limits should extend to fully cover the northern entrance to Foulger’s Gat."
 
Re: London Array - offshore windfarm-HEP

"10% of energy from renewable sources is not achievable"
sadly, this lot are intent upon doing it - helped by a subsidy, for 15% renewable which is the 2015 target, of £3.7bn per annum which we're providing ...

the greatest corporate write-off in the west was the nuclear debt of the old CEGB. nobody batted an eyelid when it happened. this time'll be different ....
 
Re: tidal power

[ QUOTE ]
It is perfectly true that the output from a tidal stream generator will be cyclical (but to a reasonably predictable pattern, unlike wind) and there will be times in the day when it will produce little or no output. But consider the combined output from a number of such generating arrays on different sites, each with it's own times of null output. As we all know, there is considerable variation in the time of slack water from place to place round the coast, and taking the output of enough geographically dispersed tidal generators should give a reasonably constant aggregate output in the short term. Longer term, output will of course vary with the springs / neaps cycle, but again it is all predictable in advance and output which can be reliably predicted can be sold ahead, i.e. actually delivering value for the electricity as well as the ROCs.

[/ QUOTE ]

Totally agree
 
[ QUOTE ]
No no no, the amount of extra methane produced by the food you need to eat to use that extra energy provides more greenhouse gases than the electric toothbrush. Add in the extra breathing needed to provide oxygen to the muscles and you might as well take long-haul flight.

Walking to work is even worse.

[/ QUOTE ]

SWMBO says that in a purely scientific experiment recently undertaken (without my knowledge) that I break wind less while cleaning my teeth with an ordinary toothbrush than at any other 3 minute period during the day. Am I green?
 
Re: London Array - offshore windfarm-HEP

Well quite! Still you can always board a pylon!

Actually if you were drifting down I bet the ladder would always be the other side.
 
[ QUOTE ]
"it can only generate electricity for up to 10 hours a day"

Enlighten me. Round my way there are only a coupla hours slack each tide cycle, equals 20 hours a day of generation if they are 'in-current' systems, rather than barrages.

Strikes me the biggest problem would be fouling/silting.

[/ QUOTE ]

There needs to be enough tidal movement to turn the turbines at a particular speed; not just enough to move the jellyfish . The 10 hours figure was from the depths of my memory. Wikipedia says 6-12 hours.

http://en.wikipedia.org/wiki/Tidal_power#Intermittent_nature_of_power_output

But, encouragingly, also says this, which is great:
However, a new Scottish invention called GENTEC venturi claims to solve the problem of intermittency and generate, at full capacity, 24/7.
 
Well, I think its a good idea - you are a right bunch of Green Nimbys

I also think that a lot of nuclear stations will be needed, too.

The alternatives are a LOT worse.
 
Re: Well, I think its a good idea - you are a right bunch of Green Nimbys

and when we have to finally pay for decommissioning them - Brown will seem like a pretty low tax grabber then.
 
Re: London Array - offshore windfarm-HEP

[ QUOTE ]


Equally, even with a 22m air clearance to the blades, thats quite close if you've got a big mast.... one of the boats we've looked at is 15m air draft..... too close for me anyway.....

[/ QUOTE ]

Recently while driving in Caithness I stopped and walked around a land based wind farm. This confirmed my view that anyone fool enough to pass so close on the windward side of a turbine as to risk their mast in the turbine would, even in a narrow monohull, be risking hull damage from the base of the tower.

Having sailed close to the stacks in the St Kilda group (for a photo shoot) I would suggest that most yacht skippers would recognise the dangers to their hull of passing that close to a fixed object in open water.

Must say most of you sound as if you have a bad dose of NIMBYism. We have both wind turbines and experimental tidal and wave power systems around our islands without any of the problems you guys are dreaming up. Ok we don't have anything as big as the London Array yet, but do have a number of no go areas for developments in coastal waters. Each of the areas have passages through or around them.

As a final thought I suggest that those who think coal and gas are so good should try living down wind of a big commercial power station.

Don't be so frightened of change, it isn't all bad.
 
Re: Well, I think its a good idea - you are a right bunch of Green Nimbys

"Yes but could the next one be up wind of you not us."
the MCA did a trial with a S&R helicopter which couldn't hold its position downwind of a quite small wind farm without fistfulls of extra throttle so downwind not a good idea? coming to think of it, upwind doesn't appeal either ....
 
Re: Well, I think its a good idea - you are a right bunch of Green Nimbys

I'm not a nuclear engineer. Why must the plant be decommissioned? We are 60 years on in the technology. More pertinent, why aren't the French making a fuss about decommssioning costs, and also have more stations?

Wind power still has that faint tang of one of those wonderful loan "offers" that drop through the letterbox at times, all the costs are in the very small print.

Time we did more research into fusion and space based microwave arrays methinks.
 
Re: Well, I think its a good idea - you are a right bunch of Green Nimbys

[ QUOTE ]
I'm not a nuclear engineer. Why must the plant be decommissioned? We are 60 years on in the technology. More pertinent, why aren't the French making a fuss about decommssioning costs, and also have more stations?

[/ QUOTE ]

At the moment it seems to be a case of building the next generation station alongside the hulk of the last generation one, which is ok with lots of land around but isn't exactly a long term solution. The annual costs of keeping a un-decommissioned plant safe and idle might be a hundreth of the costs of decommissioning (who knows, which is the point), but the burden will keep being added to.

The one thing that has really surprised me on this forum and others is that no semi-expert has come back and said, "Nonsense - the decommissioning costs are well known they are blah for this type of plant etc. etc." Only a politically based industry could possibly happen with no real idea of its own ecomonics. Nuclear is political not practical.

[ QUOTE ]

Time we did more research into fusion and space based microwave arrays methinks.

[/ QUOTE ]
Too true - and my favourite of the current ideas which is a set of mega-ships shooting up an aerosol of sea water miles into the atmosphere which will reduce air temperature and increase reflection of sunlight back into space. Each one basically about twice the size of a current supertanker with a series of pagoda-like spray tubes.
 
You must log in or register to reply here.

Share this page

Top