Tidal stream

[The Other Mike]

All are on a common shaft so can't operate independently

Nope, originally six 35MW units, now just three are operational

[The Other Mike]

None of the UK installed 1960's - late 1980's commissioned 500MW or

660MW units operated at 11kV, they are all from about 18kV up to about 25kV.

120MW units built in the late 50's early 60's might have been a bit lower.

[The Other Mike]

660MW was considered the maximum from the early 70's onwards as far as the UK was concerned. There were construction (weight) and material restrictions that made anything much bigger significantly more expensive for very little benefit. Also two of them (1320MW) was approximately the maximum credible simultaneous loss for system stability planning - it drove the design response time for Dinorwig pumped storage and for the active elements of the cross channel link to France.

[Gib Bogle]

I see the solution!

Mount windmills on airstrips to run on the wind generated by the jumbo jets. No need for nuclear power.

[Roger Chapman]

snip

Unlike wind tide is always flowing at its maximum rate somewhere around the coast. The biggest variation to take into account is the difference between neap and spring tide conditions.

Probably be cheaper than wind power and certainly more effective.

Given the need to spread the installations around the coast that could be deemed an advantage.

snip

[Tim Lamb]

That sounds likely. I suppose the extra copper/aluminium costs are lost in the 10-15 multiple of overhead costs.

regards

>

[Nightjar]

That is how generator sets normally work.

Colin Bignell

[cynic]

The corona "sizzle" as you walk in the vicinity of the overhead links from the turbine house to the transformer/switchfarm at Drax is something fierce. I felt sorry for those poor little air molecules being torn assunder :-) I bet the glow would be impressive at night.

[Gib Bogle]

I believe the main limitation is that there are not many suitable locations, i.e. places where the tidal currents are fast enough. There is a proposal, a plan maybe, to place turbines in the mouth of the Kaipara Harbour. No problem with current speed there, but the sand blizzard could prove a headache.

[The Natural Philosopher]

Make landing a bit tricky though.

But actually there's more than a hint of sense in that..it is wasted power.

[The Natural Philosopher]

Er no, its not and certainly not at the same level of power.

Nope. Wind is very very cheap. In comparison with everything except a conventional power staion.

So 1000 of these stations round that coast and we get a variable 10MW output. Great. Just what I always wanted. Not!

[Andy Burns]

This doesn't itemised the corona and iron losses separately, but together they range from 266 to 366 MW.

[Roger Chapman]

What particular tidal condition do you have in mind that is even of the same order of magnitude as the difference between neap and spring tide conditions let alone substantially greater?

I t probably would be compared with tide if the load factor was only 1%.

So where do you get your 1% load factor from?

[Gib Bogle]

He's out to lunch on that, but it remains a fact that there are probably not enough suitable sites around Britain to make this a very useful option. The current at the Kaipara Harbour site peaks at about 5 knots

- few locations get anywhere near that.

[Steve Firth]

I take it that you (a) don't have a tidal stream atlas of the UK and (b) are completely unfamiliar with UK tidal ranges.

[The Other Mike]

as the original poster said

"As a matter of interest, does anyone know how big the gennies are at a power station? Presumably you don't just have the one producing

1,000 Mwatts? What is the optimum size and what voltage are they producing at?"

[Gib Bogle]

Yes, I know, with at least one commercial-scale installation planned. But this is not "spread ... around the coast" is it? Read the post I'm responding to.

[The Other Mike]

I suspect 'harry' could provide a massive yawning chasm.

[Newshound]

Doesn't seem to worry the continentals, though!

We did have the first big superconducting motor (cooling water pump at Fawley power station, IIRC) but there are some impressive ones around now