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Ty Gwyn

Joined: 22 Sep 2010
Posts: 4613
Location: Lampeter

Posted: Mon Mar 02, 15 10:01 am Post subject: Tidal Lagoons.

This is the big news today,the Tidal Lagoon at Swansea is getting closer,the company has plans also for Cardiff,Newport and Colwyn Bay,Somerset and West Cumbria in future years.

The environmental impact study is now being processed,

The one thing that caught my ear was a quarry has already been purchased by the company to supply stone,in Cornwall,anyone know where?

There are very mixed thoughts on this scheme.

tahir

Joined: 28 Oct 2004
Posts: 45684
Location: Essex

Posted: Mon Mar 02, 15 10:04 am Post subject:
I'd rather that than an expansion of nuclear

Ty Gwyn

Joined: 22 Sep 2010
Posts: 4613
Location: Lampeter

Posted: Mon Mar 02, 15 10:15 am Post subject:
Funny you should mention Nuclear, It was mentioned that when Hinkley Point and the other Nuclear power station is built,they are estimated to use all the cement in the UK,with nothing left for other building projects.

Nick

Joined: 02 Nov 2004
Posts: 34535
Location: Hereford

Posted: Mon Mar 02, 15 10:34 am Post subject:
Given that the UK output of cement annually, would make around 50,000,000 cubic metres of concrete, It doesn't seem especially likely. Even a fag packet calculation seems to dispel that.

vegplot

Joined: 19 Apr 2007
Posts: 21301
Location: Bethesda, Gwynedd

Posted: Mon Mar 02, 15 10:59 am Post subject:

Ty Gwyn wrote:

Funny you should mention Nuclear,
It was mentioned that when Hinkley Point and the other Nuclear power station is built,they are estimated to use all the cement in the UK,with nothing left for other building projects.

Pub statistics.

Falstaff

Joined: 27 May 2009
Posts: 1014

Posted: Mon Mar 02, 15 10:59 am Post subject:
That's interesting. With Uk domestic cement production running at around 8.5 million tonnes, that's around 13,500,000 tonnes of CO2 a year That's "fossil CO2" of course.

Ty Gwyn

Joined: 22 Sep 2010
Posts: 4613
Location: Lampeter

Posted: Mon Mar 02, 15 11:10 am Post subject:
So on balance,how much CO2 will be emitted for the construction of these barrages,ie.quarrying,cement and steel production?

Nick

Joined: 02 Nov 2004
Posts: 34535
Location: Hereford

Posted: Mon Mar 02, 15 11:11 am Post subject:
Ask at The Miners Arms. They'll tell you what you want to know.

Ty Gwyn

Joined: 22 Sep 2010
Posts: 4613
Location: Lampeter

Posted: Mon Mar 02, 15 11:14 am Post subject:

Nick wrote:

Ask at The Miners Arms. They'll tell you what you want to know.

NO, i want to know what people Here think,that is ,if they know.

tahir

Joined: 28 Oct 2004
Posts: 45684
Location: Essex

Posted: Mon Mar 02, 15 11:19 am Post subject:

Ty Gwyn wrote:

So on balance,how much CO2 will be emitted for the construction of these barrages,ie.quarrying,cement and steel production?

In isolation that won't mean much. You'll need to know how that compares with (say) a nuclear power plant of equivalent output, in the case of nuclear this would I'm guessing mean decomissioning and replacement, whereas the barrage should have a much longer life span. Comparing to gas or coal would mean the total CO2 output over the operating life.

I don't know if that data is freely available but it must exist for the government to be looking at this as a viable proposition

Nick

Joined: 02 Nov 2004
Posts: 34535
Location: Hereford

Posted: Mon Mar 02, 15 11:26 am Post subject:

More fag packet maths. If Falstaff is right, and if uses the entire UK cement output, it'll create 13.5m tons of fossil CO2 (whatever fossil CO2 is). It claims to save around a quarter of a million tons each year, and have a life span of 120 years.

But, no idea what it'll actually take to build. All the plans are online. Must be straightforward to calculate.

Edit.

Quote:

What carbon emissions are created in the development of a lagoon?
The exact carbon footprint of creating the lagoon can only be identified once final designs and quantities of materials are confirmed. We estimate that the construction and installation of the lagoon will produce at least 642,000 tonnes of CO2 emissions during construction. Once operating, we estimate that the lagoon will save at least 236,000 tonnes of CO2 every year, which is roughly the same as the emissions produced by 81,000 cars. This means the lagoon will balance out the CO2 emissions produced during its construction to become carbon neutral within four years of its 120 year lifespan. After this the lagoon will be saving CO2 emissions.
Detailed information on the work carried out regarding carbon footprint and the sustainable aspects of the lagoon is provided in Volume 3 of the Environmental Statement, Appendix 5.1 Sustainability: carbon Balance, available here

https://tidallagoon.opendebate.co.uk/files/TidalLagoon/DCO_Application/6.4_5.1.PDF

Last edited by Nick on Mon Mar 02, 15 11:30 am; edited 1 time in total

tahir

Joined: 28 Oct 2004
Posts: 45684
Location: Essex

Posted: Mon Mar 02, 15 11:29 am Post subject:
This is from the lagoon website: https://tidallagoon.opendebate.co.uk/files/TidalLagoon/DCO_Application/6.4_5.1.PDF

tahir

Joined: 28 Oct 2004
Posts: 45684
Location: Essex

Posted: Mon Mar 02, 15 11:37 am Post subject:

8.0
Carbon balance and hydroelectric schemes

8.0.0.1
If the estimated equivalent tonnage of carbon emitted during the construction of the Project is divided by the annual output 400GWh) an d the operational life of the plant (120years), then the gross normalised footprint (excluding credits for recycled material
at the end of life) of the Project�s generated electricity will be 14gCO2 e/kWh. This accords with the range given in the sources described above for run-of-river facilities.

The fact that it is slightly higher than the run-of-river figures is due to the larger volume of civil works required for the seawall, but unlike reservoir hydro projects with large impoundments there will not be any CO2 emissions from vegetation for a tidal lagoon plant.

8.0.0.2
Using the most comparable grid footprint factor of 445.48g CO2 e/kWh (see paragraph 6.0.0.1), the Project saves 431gCO2 e per kWh generated. This means that, after 1487GWh is generated, the Project will have saved the carbon that was emitted during, and
as a result of, its own manufacture and construction and will be emitted throughout its life-cycle, i.e. after adding operation. This generation will be achieved after approximately 3.1 per cent of its operational lifetime, or around 4 years.

8.0.0.3
After approximately 4 years therefore, the facility is likely to be �carbon neutral�, in that it will have saved the emissions that were created in its inception. The Project is a hydroelectric scheme generating energy derived from flowing water. The total
hydroelectric installed capacity in the UK at the end of 2011 was approximately 1676 megawatts, which is around 1.9% of the current total UK generating capacity and 14% of renewable electricity generation capacity. The UK currently (2011) generates about 1.5% (5,700 GWh) of its electricity from hydroelect
ric schemes. Hydroelectric energy uses proven and efficient technology; the most modern plants have energy conversion
efficiencies of 90% and above. Hydro has a typical load factor of 35 to 40% (Department of Energy and Climate Change website: https://www.gov.uk/harnessing-hydroelectric-power, accessed 14 January 2014: Harnessing Hydroelectric Power). In the remainder
of its life, it will therefore be an efficient formof energy generation continuing to saveemissions relative to the UK grid mix.

Nick

Joined: 02 Nov 2004
Posts: 34535
Location: Hereford

Posted: Mon Mar 02, 15 11:39 am Post subject:
https://www.parliament.uk/documents/post/postpn_383-carbon-footprint-electricity-generation.pdf compares a range of footprints. The tidal barrage/lagoon is mentioned, but figures are very woolly. It also sounds like the nuclear figures tend not to include dealing with waste and decommissioning.

Nick

Joined: 02 Nov 2004
Posts: 34535
Location: Hereford

Posted: Mon Mar 02, 15 11:43 am Post subject:
But, this is why it gets my vote. https://tidallagoon.opendebate.co.uk/files/TidalLagoon/Project_introduction_to_Tidal_Lagoon_Swansea_Bay.pdf Page 20.

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