camelot-forum.co.uk

https://electrek.co/2021/10/05/ge-huge- ... erational/

The 13MW version of the Haliade-X will be used for Dogger Bank A and B.
Looks like the uprated 14MW version will be used for Dogger Bank C.

Impressive. Would love to have a go in one.

Is bigger always better?
There must be a point where diminishing returns (and increased risk) start to become apparent...
A

It must be a few years ago now, but I recall reading about designs for a theoretical 50MW WT. I remember it because it suggested having the blades face away from the wind to help reduce the stress load ..... not that I understand any of that.

I assume that WT's have a max size based on the sheer amount (and cost) of material needed to make blades longer, without breaking, which must have some sort of diminishing returns as you suggest. Perhaps there are stronger materials available, but then that too would impact costs.

Be nice to know what the 'sensible' and economic limit is thought to be?

Don’t forget Siemens Gamesa who are developing a wind turbine with power in the same bracket as the 2 aforementioned companies. None has broken ranks to say that this is getting silly.
It’s all about LCOE. I dare to suggest that costs for materials and transport per installed MWh will fall significantly. I think that they will get even bigger until some fundamental dynamic problem stops the game.

What was the CFD price paid in the latest auction for offshore wind? I remember it being impressively low, just over £50 MWh was it? Those prices would have been based on the forthcoming generation of turbines we're discussing here. It would be fascinating to see how cheap it could become theoretically.

Where is the limit? How big do the blades get before you can’t practically transport them?

GarethC wrote: ↑Wed Oct 06, 2021 7:46 pm What was the CFD price paid in the latest auction for offshore wind? I remember it being impressively low, just over £50 MWh was it? Those prices would have been based on the forthcoming generation of turbines we're discussing here. It would be fascinating to see how cheap it could become theoretically.

Hiya. The auctions use 2012 as a baseline, so the latest and cheapest CfD's were at £39.65/MWh, which after April 2021 inflation upgrade is £47.20.

At the opposite end, the most expensive were £150/MWh, now at £176.57.

Note these are 15yr CfD's, and if I recall correctly, the capacity factors of the early schemes were far higher than expected, and that helped the later auctions as developers could bid for much lower CfD's, but those high prices x high cf's have been used by the Gov to explain/blame why the subsidy pot was mostly empty, and they had to restrict future auctions.

Also worth considering that the subsidy element of CfD's is the amount that needs to be topped up to the strike price, not the strike price itself. So if the leccy was sold on average for say £30/MWh then the later auctions have a subsidy of £17, v's the £146 of the earlier ones, so the subsidy reduction is even more incredible than just the massive price reduction.


Edit - For anyone interested, all of the CfD contracts issued can be found in the CFD Register

I imagine there's a very complex relationship between blade length (more swept area is always better) vs blade weight (lighter is better, but not so light it collapses) vs tower height (higher is better) vs weight and size of the nacelle (bigger generator requires bigger nacelle, but that requires a stronger tower). And that relationship is as much about cost as it is manufacturing or technology limitations.

But when you consider how big these things are already, and being built in the middle of the sea, I must admit I can't see how they can get all that much bigger. Mind you I guess people probably said that about skyscrapers.