OT: Plans to generate electricity from 6 tidal lagoons in the UK.

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"The six lagoons - four in Wales and one each in Somerset and Cumbria

- will capture incoming and outgoing tides behind giant sea walls, and use the weight of the water to power turbines. The cost of generating power from the Swansea project will be very expensive, but the firm behind the plan says subsequent lagoons will be able to produce electricity much more cheaply. It says the series of six lagoons could generate 8% of the UK's electricity for an investment of £12bn."

"Tidal Lagoon Power is in negotiations with the government over how much it can charge for its power. It wants £168 per MWh hour for electricity in Swansea, reducing to £90-£95 per MWh for power from a second, more efficient lagoon in Cardiff. The £90 figure compares favourably with the £92.50 price for power from the planned Hinkley nuclear station, especially as the lagoon is designed to last 120 years - at a much lower risk than nuclear."

The bit that caught my notice was the comment on the radio that they would cost about as much as a nuke.(Not sure if that means each, or all together, or just for the electricity rather than the capital).

So why not build a nuke. At least they produce power continuously, not intermittently, and don't require an equivalent amount of generating power just sitting there for when the tides are slack!

Reply to
Chris Hogg
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I take in what you're saying - but I would go ahead with wave *and* nuclear. Wave power is the only sensible "green" way to produce enough power to bother with (unlike these stupid windmills), and is safer than nuclear, I suppose. I'm a tad disappointed that the obvious scheme has not been included - The Severn Barrage - as this could produce such a huge amount of safe power.

Reply to
Bob Henson

In what way is it safer than nuclear "you suppose" ?

Reply to
Tim Streater

"I suppose" because the chances of any real problems from either are very, very slim - hence the problem are more theoretical than real. Were there to be any, the problems are different. Shredding fish is the main one with wave power, and other ecological changes from any dam effect. Nuclear problems would be somewhat worse. I wouldn't stop to consider either - the absolute certainty of energy shortage problems from not rapidly going ahead with one or preferably both ideas (and fracking) far outweigh any risks involved.

Reply to
Bob Henson

And they don't silt up affect wildlife or possibly change the erosion patterns locally either. Brian

Reply to
Brian Gaff

Wave power is struggling to make progress. The Pelamis 'snake' went into administration over a year ago*. The much-vaunted Wave Hub off the north coast of Cornwall had one device connected to it last summer, made by Seatricity. It was there for 5 weeks before being towed back to Falmouth for 'routine inspection before we deploy her on a continuous basis into the winter' (quoted from a Seatricity e-mail). It's still being 'inspected', some six months later. Something obviously went badly wrong.

A comment I read a while ago about all wave energy devices is the difficulty in making them robust enough to cope with the extremes of sea conditions they would experience. For example, 'Significant wave heights'** in the vicinity of the Wave Hub can vary from less than 1 metre to getting on for 10 metres, that's 3 to 30 ft in old money. And the maximum wave height can be significantly higher than that***. The destructive power in those big waves is massive, as the Victorian engineers found when they built the rock lighthouses off the Cornish coast. You only have to see the very heavy construction of various navigational buoys and their anchor chains around the Cornish coast to appreciate what's required to cope with the conditions.****

As to the Severn Barrage, it's been kicked around for many decades. At the moment it's in touch because the environmental lobby complained about loss of wetland and mud-flat habitat for wading birds etc. Silting up of any barrage or lagoon will have to be dealt with, but not impossible to do, I guess.

And how much CO2 would be emitted in making all the concrete for these barrages, and what's the CO2 recovery period, IYSWIM?

I can only see renewable energy becoming viable when some means of storing electricity on a massive scale is found. ATM we only have pumped storage, and that's very dependant on the appropriate topography, which we don't have much of. IMO no renewable scheme should get the go-ahead unless it goes hand-in-hand with an electricity storage scheme, planned and costed together as one unit.

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Reply to
Chris Hogg

That, as you say, is impractical - but there is unlikely to ever be an alternative. I can't see a problem in that regard with wave power any more than with nuclear or anything else - you still can't store the electricity - so you can't use that as an argument for abandoning any scheme of any type - not even the pointless windmills. However you generate, you still can't store - so I can't really see the point you're trying to make.

Reply to
Bob Henson

The difference is being able to increase or decrease the output on demand, which renewables by and large can't do. Hence needing non-available storage. Fossil and nuclear *can* be ramped up or down.

I'm still interested to know about (and haven't heard anything about recently) a plan for Oz to build a large number of solar stations that store some of the energy as molten salt for overnight use. They get enough sun and have enough useless land for the idea to be possible viable.

Reply to
Tim Streater

Well no, it (tidal. not wave power) is not sensible, its not green, and it doesn't produce much power and then not continuously, which makes its output almost worthless.

I'm a tad disappointed that the obvious scheme has

Extremely unsafe power. As well as ripping the ecology and environment of a thousand square miles to pieces.

And achieving yet another intermittent power source at huge expense that will let us down when we need it most.

Reply to
The Natural Philosopher

The Severn barrage is not wave power.

and other ecological changes from any dam effect.

Reply to
The Natural Philosopher

OK - hairs duly split. Everyone, including you, knows what I meant. "Lagoon power" or whatever you like to call it - holding back sea water (which has bumps on it called waves) and using it to drive generating devices.

Reply to
Bob Henson

Which ultimately shows how dumb you are.

The key is *dispatch*. The ability of a power station to take a source of *stored* energy, like coal, or gas, or a uranium nucleus, and turn it onto power *on demand*.

By total contrast with wind wave solar and tidal power all of which will generate power only when the energy is there in the environment, - so need an EXTRA store to provide the dispatch.

That store is currently coal, gas or nuclear...

Only biofuels and hydroelectricity and maybe geothermal can be considered to have energy *stores* associated with them. And hence be 'dispatchable'

Intermittent non dispatchable energy is worse than useless. It costs huge amounts of money in terms of either storage or co-operation with fossil and nuclear and extra grid interconnects to provide a solution that hydro or nuclear or coal already has built in.

I am struggling to understand whether you really are that stupid, or if you are simply another shill for the renewable industry like Harry who knows they are lying and is paid not to care.

Reply to
The Natural Philosopher

Why do you think you can't change the number of generators being driven, or the amount to water passing through or bypassing them to produce exactly the amount of power anywhere between none and flat out? The folk I was listening to on the BBC this morning were making that point as a specific major advantage of lagoon power or tidal power - as I'd better call it to please the excessively pedantic - the maximum power is exactly calculable at the outset, and can be varied to suit.

I hadn't heard of that - but it sounds feasible in parts of Oz.

Reply to
Bob Henson

Quantify huge and safe, It's certainly not good value for the consumer.

Only imbeciles, or the other greens in receipt of the subsidy would think it a good idea, for everyone else it is government sponsored theft

Reply to
The Other Mike

Christonabike

I thought some of the comments on here have been cretinous in the past but the loons are out in force on the beeb website.

Reply to
The Other Mike

The other way round. Even if I was wrong, you have a very abrasive way of making a prat of yourself - how about some politeness? Or is that another concept too complex for you to understand?

So, you will be able to quote me all the times when the tides have been none existent recently and were not available for driving turbines on a daily basis? You know, when gravity was suspended and the moon wasn't there, and the wavy stuff stopped going up and down and in and out, in case the concept of tides is a tad complex for you?

Agreed with wind power and solar power in the UK. Wind power is a total waste of time and effort. But tidal power is available all the time, even more predictable than hydro-electric, and the generation of power from it to the grid can be switched on and off, or turned up and down, as required, just as easily as any other form of power.

Are you really that offensive, as well as that dim?

Reply to
Bob Henson

What is intermittent about it? When do the tides stop coming in?

Reply to
Bob Henson

At high tide, happens twice a day

Google undulation point

Reply to
The Other Mike

Quote your figures for that - I've seen quite a few references on TV and elsewhere that claim it could be economically viable.

It seems everyone is determined to be as offensive as possible today. I'm as far from a tree-hugger as you can get, so I assume you class me as an imbecile? I find those who resort to being offensive first are usually those with the most limited powers. The rest of us wait until some prat has annoyed us before being offensive.

Reply to
Bob Henson

So you made your other offensive comments before you'd even read about the project concerned? Hmm, what conclusion should I draw from that?

Reply to
Bob Henson

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