Severn Barrage

[John55]

Prove it!!

I have never heard of any credible claim which suggests the heat from the generation and use of electricity has any impact on global temperatures.

The usual culprit is held to the radiated energy from the sun. The human impact is in relation to what happens to the solar energy when it arrives in the atmosphere.

 

[pablo]

Any barrage scheme has to be matched with a base-load type power station for when the tides ain't running fast enough. Such internittant use is uneconomical so you have to factor that into the equation. The barrage schemes I've seen are all north of the ports and canal entrance so no effect there. I get the impression that few have done any research on this before posting.

 

[John55]

Any barrage scheme has to be matched with a base-load type power station for when the tides ain't running fast enough. Such internittant use is uneconomical so you have to factor that into the equation. The barrage schemes I've seen are all north of the ports and canal entrance so no effect there. I get the impression that few have done any research on this before posting.

The UK Government feasibility study published in 2010 did look at several schemes including the Weston - Cardiff route (Bream Down to Lavernock). This was relatively good value in terms of cost of electricity compared to other sources but not good enough to convince HMG to spend any more money. The report did mention the 8 hours out of 24 for useful generation from the tides which is even worse than I realised.

 

[Cliveblackpool]

Imo the Severn Barrage would be neutral re planet warming.
The electricity generated is taking Kinetic energy from the river/ tides, which may 'cool' the water in the estuary by a tiny fraction of a degree. I suppose if the electricity generated was used to reheat the water, it would then be the same temperature as before the barrage was built!. Billions of gallons a second passing around the estuary!
An aluminium plant may set up close by to take advantage of off peak power.
Although the estuary inside the barrage would be safer for small craft, but when the turbines are all on, the drop/ increase in level of the water would be dramatic!
Tide tables would be issued by the electric company, after they have worked out peak demands!
eg Adverts during Corrie the river would drop 6 feet!!

 

[sbt]

Any barrage scheme has to be matched with a base-load type power station for when the tides ain't running fast enough. Such internittant use is uneconomical so you have to factor that into the equation.

Unless you impound the tide, which allows you to control output more effectively. This is what the latest scheme plans to do. It doesn't give you 24 hour generating capacity but you do have more control.

The barrage schemes I've seen are all north of the ports and canal entrance so no effect there. I get the impression that few have done any research on this before posting.

Some of us have done a bit. There are a number of proposals around but the one currently being considered is a Severn Barrage on the Cardiff-Weston (Lavernock Point to Brean Down) route, not one of the other Severn Estuary Tidal Power Schemes, most of which, as you say, are upstream of Avonmouth.

However even the furthest upstream of the proposals I have been able to find, the Beachley Barrage, would require locks, although smaller than the Cardiff-Weston scheme, to allow shipping to pass upriver to the port of Sharpness, which currently handles vessels of up to 6,000 DWT.

Presumably by the 'canal entrance' you mean Sharpness? The only other places I can think of you meaning are Frampton (where the Thames and Severn used to come out) and Over (where the Herefordshire and Gloucestershire entrance is). As I say, I can find no proposals that high up the river, although I suppose that small turbines on the existing weirs at Llanthony and Maismore (near Gloucester) could be used in a very small scheme, although even then Llanthony Weir would require the, currently out of use, lock to be retained for access to the Herefordshire and Gloucestershire Canal (which is under restoration - I know, I have put enough weekends work into restoring it!).

 

[HSTEd]

A privately funded barrage will just result in a bunch of foreign venture capital companies demanding insaley high prices for the "low carbon" electricity after demanding huge construction subsidies in terms of loan guarantees and the like.

This is exactly teh sort of project that should be paid for by the state, operated by the state and owned by the state.

But anyway, compared to simply starting a crash programme for fast reactors... I don't think it is really viable.

EDIT:

AS to the question of whether direct heating use on the planet's surface is causing it to heat up, it is projected that this effect is probably just detectable but since the total heating flux the planet is exposed to by solar radiation is far greater it is unlikely to be important.

As to energy efficiency in avoiding this effect: a gas boiler is at maximum 95% efficient, so 1 unit of gas thermal energy is capable of producing 0.95 units of heat for space heating.
Whereas a fast reactor can use one 1 unit of thermal energy to produce 0.4 units of electricity, which can be used in an air-to-air heat pump that would produce nigh on 2 units of useful heat.

So to deliver the same amount of heat at the end (for space heating, a primary use of heat these days) you would need half as much thermal energy released. (you can substitute a gas fired CCGT plant for the fast reactor if you want, in which case its even more incredible since modern plants have reached 50% efficiency now)

 

[pablo]

The marginal cost of running, say, a CCGT plant full time as opposed to matching the barrage half time is far less than the full-life cost of the barrage so this scheme will be never be more than a nice political windmill.

 

[brianthegiant]

So you want to increase our dependence on Russian gas? remember when they cut the supply to Europe over an argument with Ukraine? Germany was getting very nervous, though unlike us, Germany has the sensible approach of higher targets for energy efficiency and renewables.
That's all we'll do with another dash for gas, we're no longer net exporters, as the north sea is dwindling.
I suspect also the current enthusiasm for fracking will dwindle once people start getting polluted drinking water like in the US.

 

[Cliveblackpool]

So you want to increase our dependence on Russian gas? remember when they cut the supply to Europe over an argument with Ukraine? Germany was getting very nervous, though unlike us, Germany has the sensible approach of higher targets for energy efficiency and renewables.
That's all we'll do with another dash for gas, we're no longer net exporters, as the north sea is dwindling.
I suspect also the current enthusiasm for fracking will dwindle once people start getting polluted drinking water like in the US.

Imo drinking water is a more valuable resource than fracking gas.
Our reliance on electricity for virtually everything today makes having dependable power supplies essential. In a power cut supermarkets close, and today you would be hard pushed to even find a pub still serving!!

Gas should not be wasted generating electricity.
It is ok to have some gas fired stations used for peak demand, so only burning gas for say 4-6 hours a day.

As already said the Severn Barrage would have to be State owned for us to enjoy the long term benefits.

 

[HSTEd]

So you want to increase our dependence on Russian gas? remember when they cut the supply to Europe over an argument with Ukraine? Germany was getting very nervous, though unlike us, Germany has the sensible approach of higher targets for energy efficiency and renewables.

The Germans threw away any possibility of ever becoming independent of massive gas imports from the east when they decreed that nuclear was evil and we must all worship the wind farms and photovoltaics.

The only people in Europe with a chance are the French, and even they are beginning to move in the wrong direction.

That's all we'll do with another dash for gas, we're no longer net exporters, as the north sea is dwindling.
I suspect also the current enthusiasm for fracking will dwindle once people start getting polluted drinking water like in the US.

Indeed, but a massive crash programme of fast fission reactors (like that inconvenient truth for the anti-nuclear movement, the BN-600 that has been operating commercially for years and cost no more to build than an equivalent soviet PWR). would allow us to divert our relatively small but significant production of natural gas and coal to liquid fuel production, probably amount to at least 500,000bbl/day in 2030.

As for the Severn Barrage, it is almost certainly not viable for grid electricity production, but systems like hydrogen production and the proposed solid-state ammonia synthesis would allow it to produce vast quantities of fertiliser and hydrogen which could be used for the aforementioned coal hydrogenation and also for production of industrial chemicals like methanol.

As to the environmental damage caused by fracking, technologies such as the liquid propane fracking will almost eliminate this issue, as will the fact that the majority of British Shale Gas reserves appear to be off shore where there is no drinking water to contaminate.

And last year's profits in the water industry (some £2.2bn apparently) would cover the capital costs of renationalisation using current government financing rates and would allow the entire domestic water supply to be desalinated with no increase in prices.

In short:
The severn barrage is not viable for grid energy production without huge subsidy, but it may be viable for the production of hydrogen or similar as this is not constrained by the same availability requirements, but off peak nuclear probably wins anyway.

 

[route:oxford]

The severn barrage is not viable for grid energy production without huge subsidy, but it may be viable for the production of hydrogen or similar as this is not constrained by the same availability requirements, but off peak nuclear probably wins anyway.

It does still have the massive benefit of being a supply of energy that can be predicted with absolute accuracy - unlike the wind or solar.

All it takes is intelligent use of the power.

 

[D365]

The Germans threw away any possibility of ever becoming independent of massive gas imports from the east when they decreed that nuclear was evil and we must all worship the wind farms and photovoltaics.

The only people in Europe with a chance are the French, and even they are beginning to move in the wrong direction.

I was about to mention how ridiculous this is. I could understand in Japan's case for shutting down nuclear, but Germany? It's a massive PR stunt; nuclear energy is the only clean, reliable, build-nearly-anywhere electric generation technology we have today. Only problem is that the general public is "scared" of it, but waste storage and safety is getting better and better. The British government needs a proper policy for future electricity if we want electric trains, cars and further digital luxuries.

Severn Barrage? Only if it's worth the detriment to shipping, the natural beauty and the expense. Judging by the posts here, it's a mixed opinion.

 

[dalmahoyhill]

I don't know!
Maybe the cognoscenti will let us know.
I thought the electrification programme would clear all lines to W10, but there must be a practical limit to the tunnel (although oversize stuff could run via Gloucester).
I was under the impression that the only real tunnel problem was that it was "wet".
If NR can solve that problem to cater for electrification and IEP then it should be fit for a long time.

I believe its track clearance for catenary. The track bed would need to be lowered for traditional catenary in the tunnel due to gauging issues. Difficult on a 4.5mile long tunnel. In the mound tunnel in Waverley they used an overhead rail system to deal with this, i dont know if this solution is speed limited.

i would second many of the posters comments on the difficulty of a track on a barrage over locks. A feasibility study 3 years ago said £20bill for a 8gw scheme for weston to penarth. A crossing at the old severn bridge was 600mw but only a billion or so. The further upstream it is the better it would be to use as a transport corridor but the generation is poor.

The government rejected taking it any further due to cost against lack of experience in building one.

Maybe the should consider the solway or morecombe bay first?

 

[HSTEd]

I believe its track clearance for catenary. The track bed would need to be lowered for traditional catenary in the tunnel due to gauging issues. Difficult on a 4.5mile long tunnel. In the mound tunnel in Waverley they used an overhead rail system to deal with this, i dont know if this solution is speed limited.

It is speed limited... to the low low speed of 250kph according to recent experience using tunnels in Switzerland and Germany.

i would second many of the posters comments on the difficulty of a track on a barrage over locks

Will have to put the track on a viaduct on top of the barrage near the locks to get over them, and the gradients required for a decent degree of air draft without miles and miles of viaduct on top would probably prevent the use of the line for freight which prevents the closure of the Severn Tunnel probably.

 

[pablo]

Reliance on Russian gas? Google both Shtokman and Yamal and then tell me who will be dependent on whom? Russia needs all the currency it can get. Diversity of supply is improving. Soon Umerika will be a major exporter. They don't mind dirty water; they've got the energy to clean it. We need to put ourselves in the same position and stop all the theoretical controversy.

 

[HSTEd]

Reliance on Russian gas? Google both Shtokman and Yamal and then tell me who will be dependent on whom? Russia needs all the currency it can get. Diversity of supply is improving. Soon Umerika will be a major exporter. They don't mind dirty water; they've got the energy to clean it. We need to put ourselves in the same position and stop all the theoretical controversy.

Actually there are major problems, excluding environmental ones, with the shale gas industry in the US.

They aren't sure if they are actually making money at the current price of natural gas and there is discussion that it will have to rebound back to approximately what it was originally for them to make worthwhile returns.

Also all the increases in shale gas production will cause in the long term in the US is the deployment of GTL plants, American governments are always going on about energy security and will they will thus attempt to substitute shale gas fro some of those enormous oil import flows they have.

As to the Russians being dependent on us.... the Russian economy is improving rapidly and they could probably survive cutting off the flow of gas for a few weeks, it is highly doubtful that we could, even with LNG, there is simply not enough LNG capacity to provide for Europe in its entirety and we are probably rather near the end of the line.

We would be forced to bow before our overlords in the Kremlin long before they felt anything more than minor economic problems as a result.

Then there is the massive energy boom in China and India which is going to swallow everything by the looks of it.

 

[scandal]

I have never heard of any credible claim which suggests the heat from the generation and use of electricity has any impact on global temperatures.

The usual culprit is held to the radiated energy from the sun. The human impact is in relation to what happens to the solar energy when it arrives in the atmosphere.

Are we still on this? I'll link you to the following thread where you'll see plenty of argument against your opinion.

http://railforums.co.uk/showthread.php?t=70737&page=4

Without distracting from the argument electricity is a clean form of energy, it is just that some of the means of generation of it are problematic for the environment, hence the differentiation between renewable (which does not in my opinion include Nuclear) and non-renewable energies, remember the UK Secretary of State for Energy is also responsible for Climate Change.

In regards to the actual topic of discussion, most of the funding appears to be forthcoming from sovergin wealth funds as opposed to funding for the channel tunnel through if I remember bonds and flotation. I'd argue that over the lifespan of a project to provide 5% of the UK's electricity needs in a renewable way this is a financially benefitial investment, hence the interest from the private sector, especially considering the 2008 Climate Change Act constraining future UK energy policy decisions (see Coalition dithering over new power stations).

 

[HSTEd]

Without distracting from the argument electricity is a clean form of energy, it is just that some of the means of generation of it are problematic for the environment, hence the differentiation between renewable (which does not in my opinion include Nuclear) and non-renewable energies, remember the UK Secretary of State for Energy is also responsible for Climate Change.

Why would nuclear not be renewable?

Fast fission reactors make uranium resources effectively unlimited, even if Uranium was as expensive as platinum is right now the cost of electricity would be increased by about three-quarters of a US cent per kWh, so about half a penny or even less.

Seawater extraction of uranium has recently been priced at roughly $96/lb (roughly twice current mining costs) and billions of tonnes of uranium are available in the ocean. (note as it appears that the ocean is in equilibrium with the oceanic crust in terms of uranium, extractable resources will be very much greater than this, possibly an order of magnitude).

Every "black shale" and even granite becomes a viable uranium ore with fast fission technologies.

As for waste, fission product activity will be below the original activity of the source uranium in 300 years or so, at which point the waste which was immediately vitrified in a sodalite type glass derived from zeolite can be dumped in mid ocean and never trouble anyone again, conservatively remaining intact for millions of years.
Even if you don't want to dispose of them in deep ocean, after 300 years of decay the radioactiviy will be so weak that there would be no cooling issue from simply stacking thousands of canisters in a giant pile which would take up hardly any space whatsoever.