Diesel - seriously thinking of giving up cycling

[Bonefishblues]

Show me a Civil Engineer who would turn down a crack at building something Really Big

What's your point?

That they would always present as confident about what would represent the project of a lifetime for any Engineer.

[pwa]

For anyone keen on renewables Swansea Bay may soon be a good place to go and see them in action. From Mumbles Pier you will be able to see the new biomass power station now under construction at Margam, wind turbines on the hills behind, and possibly the barrage if it happens.

[al_yrpal]

https://en.m.wikipedia.org/wiki/Rance_T ... er_Station has been in operation since 1966 so these lagoons are not a new concept. IMO we should be building a Severn barrage, but the other lagoons mentioned look good. The birds can go elsewhere and will adapt. As for greenhouse gases what about hedgehog farts? A tunnel for Stonehenge too, someone has ungummed government!

Al

[reohn2]

Show me a Civil Engineer who would turn down a crack at building something Really Big

What's your point?

That they would always present as confident about what would represent the project of a lifetime for any Engineer.

See Al's post above

[Vorpal]

Have there been comparative studies investigating methane released from e.g. tropical rain forests. As I understood it, this is biological origin methane coming from decomposition of biological material and biological material rots all over the place (under varying conditions). As a report is seems rather short of references (those given are just to other similar articles from the same organisation) and they do comment that a significant contribution of this methane generation is actually caused (indirectly) by fertiliser run-off making it more an issue of farming practices than electricity generation.

So I can appreciate they may be some negative impacts to hydro generation but also, I was not overly impressed or convinced by the article.

Ian

I have to admit the article wasn't the best, and definitely lefty-greeny I had a little trouble finding anything that wasn't. I know the Canadian government did an extensive study on this, but I didn't turn it up when I was looking the other day.

[pwa]

https://en.m.wikipedia.org/wiki/Rance_Tidal_Power_Station has been in operation since 1966 so these lagoons are not a new concept. IMO we should be building a Severn barrage, but the other lagoons mentioned look good. The birds can go elsewhere and will adapt. As for greenhouse gases what about hedgehog farts? A tunnel for Stonehenge too, someone has ungummed government!

Al

Back in the mists of time when I was a Geography student Rance was generally considered a flop due to silting. It was used as an example of what happens when you lunge at a "solution" without thinking it through.

As for the wildlife being able to just go somewhere else if you barrage the Severn, you go to Slimbridge and tell them that!

[Bonefishblues]

I'm sure that silt won't be an issue in the Severn Estuary.

Birds can fly, innit

(From a position of consumate ignorance, but a piscatorial and all-things-watery bias) On balance I'd rather see offshore wave generation, or nuclear, I think.

[al_yrpal]

The Rance is on a river estuary so they would have to dredge the river. There is lots of silt in the Severn estuary, I am sure that they will do a hydraulic model at Wallingford and study this. I am sure dredgers are going to be part of the scheme. I hope these projects arent derailed by ignorant eco lunatics focussed on micro problems. The bigger picture is the one to focus on, a difficult task for politicians.

Al

[rjb]

I'm sure that silt won't be an issue in the Severn Estuary.

(From a position of consumate ignorance, but a piscatorial and all-things-watery bias) On balance I'd rather see offshore wave generation, or nuclear, I think.

Silt is a major issue in the severn estuary. The floods on the somerset levels in 2014 were exacerbated by the lack of dredging on the rivers Tone and Parrett. These rivers silt up due to tidal action and silt brought down the severn being washed back up the Parrett and tone.

[Bonefishblues]

OTOH it's notable that its the costing is now being cited over 120 years lifespan, yet the developers themselves initially quoted the useful lifespan (silting...) as being 60 years. That's not a small difference. These are some of the most silt-laden waters in the UK (as a drive over either bridge at low tide will illustrate (or a holiday in Weston-Super-Mud, for that matter!).

It's so frustrating being a member of the public - one wants objective info to form an informed opinion, but it's hard to get.

[mjr]

OTOH it's notable that its the costing is now being cited over 120 years lifespan, yet the developers themselves initially quoted the useful lifespan (silting...) as being 60 years. That's not a small difference. These are some of the most silt-laden waters in the UK (as a drive over either bridge at low tide will illustrate (or a holiday in Weston-Super-Mud, for that matter!).

It's strange to the casual observer how the Severn behaves, though: the next bay north to WsM is called "Sand Bay" and lives up to its reasons. Also, if you fall upon the rocks at Knightstone in WsM, your body will probably wash up at Clevedon. There are people who understand more-or-less how it works, but I'm not one.

How about other tidal lagoons along the Severn? Generate power without the worst impacts of a barrage.

It's so frustrating being a member of the public - one wants objective info to form an informed opinion, but it's hard to get.

Especially if you post on a forum instead of asking the proposers.

[Psamathe]

... The birds can go elsewhere and will adapt....

....
As for the wildlife being able to just go somewhere else if you barrage the Severn, you go to Slimbridge and tell them that!

Some years ago I was all "protect the wildlife", but feel that these days with the threat we have created that will impact ourselves AND the wildlife greater ingenuity and flexibility are needed.

Do nothing, continue to burn hydrocarbons unconstrained and there will be no tomorrow for us and the environments the wildlife require will not be their either. So we must do something and whatever we do will have negative impacts. So it comes down to what steps can be taken to mitigate for the environment/wildlife and what compromises can be made over what and where we take steps.

Allow climate change to continue unabated and Slimbridge is probably a goner anyway (as the climate changes and the wildlife they serve has to go elsewhere or die out). We (as a species) have put ourselves in a stupid position where all paths forward have unfortunate consequences (and whilst it's probably no conciliation to the wildlife, I suspect the human race will be one of the species to suffer most).

And whilst we are aware of the dangers of climate change (yet do not enough because of the impacts on the wealthy elite) there are also plenty of other things we are doing that will cause us plenty of other problems (and we know about them and we do little because those things tend to create profits for a few elite).

Ian

[al_yrpal]

Its all about doing the least harm…

Slimbridge will be protected - a national treasure.

Al

[pwa]

The Rance is on a river estuary so they would have to dredge the river. There is lots of silt in the Severn estuary, I am sure that they will do a hydraulic model at Wallingford and study this. I am sure dredgers are going to be part of the scheme. I hope these projects arent derailed by ignorant eco lunatics focussed on micro problems. The bigger picture is the one to focus on, a difficult task for politicians.

Al

I hope that by "micro problems" you do not mean the reliance of migratory birds on the mud flats of the Severn Estuary. If we cannot come up with solutions that do not impact adversely on what remains of our wildlife, I give up. I'm certainly not saying "never" to the idea of a Severn Barrage, but we should not give it the (very expensive) green light until we know that the future our wildlife in the estuary has been assured. And given the very high cost of the barrage we should ask if that is the most effective use of that expenditure. What, for example, would happen if we spent that money on smaller renewable projects around the UK? Or on nuclear?

The Rance barrage was seen as a failure just a few years after it started to operate because unforeseen levels of silting greatly reduced its capacity. I expect the lessons have been learned. It is an example of how important it is to focus on the details of such projects.

[Psamathe]

... And given the very high cost of the barrage we should ask if that is the most effective use of that expenditure. What, for example, would happen if we spent that money on smaller renewable projects around the UK? Or on nuclear?
....

Or on e.g. HS2 or tunnels under national monuments, etc.. I have the impression from some of the massively expensive projects the government is pursuing that capital cost is not an issue these days. It only seems to become a "problem" when it is for projects that help lower our pollution of the planet (or help protect wildlife/diversity).

Ian