Another attempt at Swansea Bay Tidal Lagoon

[dan_b]

https://www.swansea.gov.uk/BlueEden

Where's the money coming from this time?

[Stinsy]

These kind of scams really annoy me. It annoys me even more that so many scams use "Renewable Energy" as their hook.

How much wind/solar could you buy for £1.7bn? How long 'till the first kW of wind/solar is online? What is the risk that a wind/solar project will fail to generate even a single kWh?

[dan_b]

Why do you think it's a scam?

[Stinsy]

"Scam" might be too strong a word. If your aim is to reduce CO2 by generating renewable energy, this isn't the best way to go about it. If your aim is to enrich yourself personally then promoting a scheme such as this is a REALLY good way to go about it.

[AE-NMidlands]

There is a sorry history to this particular scheme (or the previous one in the same area.) Like proposing to use lots of stone from the promoter's own quarry...
Tidal - especially when coupled with battery storage - should be good, but there are other things to consider, plus loss of habitat is something we can't continue to ignore.

btw I can see that, no matter how well established solar and wind generation are, there will frequently be times when it is necessary to draw from storage of some sort. The output from solar and turbines costing the same amount might well be nil some of the time, so comparing their cost or what we could get for the same money is irrelevant.

A better question is "could we get the same amount of storage from another scheme at a fraction of the price and with less habitat destruction?"

[nowty]

These kind of scams really annoy me. It annoys me even more that so many scams use "Renewable Energy" as their hook.

How much wind/solar could you buy for £1.7bn? How long 'till the first kW of wind/solar is online? What is the risk that a wind/solar project will fail to generate even a single kWh?

Back of fag packet calculations using factsheet from TRIG, one of my favourite renewable investments because they have a good mixture renewable assets, for last year they had a NAV of £2.2bn, an installed capacity of around 1.8GW and generated 3953 GWh. So I work that out to be around an average of a 25% capacity factor.

No info in that press release from "Blue Eden" on what the annual yield will be so I cannot make a comparison.

https://www.fundslibrary.co.uk/FundsLib ... Wt0m8Y&r=1

[Mart]

This is a really difficult subject because the Swansea scheme is relatively small, and therefore expensive, but could prove the idea and technology for other schemes such as the Cardiff Tidal lagoon that should be 10x larger, but generate at around half the cost since you get more bang for your buck when you enlarge a circle - doubling the circumference gives a fourfold increase in area, and this would apply to building a barrage wall, v's volume of water contained.

So first off we need to know if it will bring future benefits from cheaper, larger schemes, or not.

But the main additional value for these schemes is predictable generation every day. I assume the generation profile will be the same (as earlier schemes?) so we'll see 4 x 3.5hrs of generation each day, with a 2.5hr period between each for the water level outside to rise, or fall. That means that most days there will be generation covering at least some of the 5pm-7pm peak, and every day covering at least some of the wider 4pm-8pm period. Also generation may be time shifted a bit to help with demand, but opening the floodgates (so to speak) outside of peak height differential would mean less energy overall.

I don't know what the additional value for that predictability is, but it obviously has some, and not just for itself, but also for a wind/solar/storage set up, since that will be able to lean partially onto the tidal predictability.


When I first started reading up about Swansea I think the cost estimates were around £85/MWh or higher, which is not cheap, but compared well to off-shore wind at the time, but since then offshore wind has fallen from around £150 down to £40 (2012 baseline), which does not help tidal, and especially Swansea!

So a great additional tool for the RE toolbox, with some additional social benefits and flood protection, but whether or not it now stacks up against other technologies and storage I don't know?

[Ken]

I think it will just silt up like everywhere around there.

[dan_b]

I wonder, if schemes like this are to have some reason to exist - perhaps it's not for the stage of zero carbon generation we have now - but it's for the "last 10%" scenario where things get much more difficult and more expensive?

[Stinsy]

I wonder, if schemes like this are to have some reason to exist - perhaps it's not for the stage of zero carbon generation we have now - but it's for the "last 10%" scenario where things get much more difficult and more expensive?

I’m not so sure.

I keep seeing houses with beautiful, rectangular, south-facing roofs that are unadorned. The sort you could fit an 8kWp array on easily. A 16-24kWh battery pack would ensure the house wouldn’t need any grid power at all for 40ish weeks a year.

A new distribution centre was built near me a few years back. Its roof is many football fields in area but not a single PV panel is in sight.

The days/weeks when solar produces very little are usually windy / rainy so hydro/wind augments solar nicely. There is still room for innovation in grid-scale storage be it vast battery arrays, pumped hydro, cranes stacking concrete blocks, trains driving up and down hill, or whatever.

Projects such as this one exist only to enrich their promoters. And they can achieve that without generating a single kWh.