OT Tidal power

[The Other Mike]

Can someone press harry's repeat cancel button?

[The Other Mike]

I'd hope by *20202* they might have just cracked building s solar cell that lasts more than a couple of decades, a wind turbine that lasts longer than a series of Strictly without going bang, and a means of burning greens without them putting out the fire.

By 20202 we might have 10000 ppm of CO2 in the atmosphere :)

[The Other Mike]

It has previously agreed that we need to flood Scotland, all of it, to what was it 200 metres?

With Alex Salmond and that gormless female sidekick in concrete boots chained to the bottom of Loch Ness, it demonstrates Scotlands contribution to the green economy.

[The Other Mike]

No, in a message from the future they just announced that they need another 50 years.

[The Other Mike]

I got redirected to this page

[The Other Mike]

Have the jocks taken it over?

[John Williamson]

Dagnabbit!

[Chris Hogg]

YKWIM!

[Nightjar]

This claimed to give 50,000 litres a day with a 100ft lift:

[Adam Aglionby]

Hydraulic accumulator and go far enough out that the tide dosent empty, wave rather than tidal power, Pelamis

[Chris Hogg]

Oh interesting! Thank you. It doesn't say where it is AFAICT, but a set of three Green and Carter pumps were unearthed (literally) in the valley below Heligan Manor* in Cornwall some 20+ years ago. They had a (combined?) capacity of 9.5 gpm (~62,000 l/d), pumping against a head of 300 ft and over a distance of 1.5 miles. They were refurbished with G&C's help. See

But you'd still need an awful lot of them to run a decent sized tidal generating system, and the volumetric efficiency (water pumped / water used) is poor. See

and scroll down to 'Efficiency'.

• 'The Lost Gardens of Heligan'

[Tim Streater]

How long will it take to fill the lagoon. No point if the tide has gone out in the interim.

[Nightjar]

Until I found that video I hadn't realised how noisy they are.

I like the 'guaranteed forever' on their products and the fact that they have spares for all ram ever made on the shelf, presumably because they have made very few changes to the design in the past couple of centuries.

Oh yes. Hydraulic rams are only useful if you can put high volumes of water through them. In that case, if you want electricity, an Archimedean screw generator would probably be a better option.

[Vir Campestris]

Ripple on tides? Whatever next :)

More seriously though - one tidal system has a power output ranging from

0% (at high or low tide; slack water) to 100% (mid tide, peak flow)

Two out of phase add up nicely - I think if they are true sines you'll get 70% of peak at worst.

Andy

[Tim Streater]

They have to be exactly out of phase and the same amplitude, otherwise you get residual ripple.

[harryagain]

Drivel as usual. Low head but large volume.

[harryagain]

You never read it did you shit-fer-brains? Or not capable of understanding it.

[harryagain]

As the "fuel" is free, neither here nor there.

[harryagain]

Do you know what a hydraulic ram is?

[harryagain]

My aren't you the half wit. All work is done by converting one form of energy to another.

And you claim to have been Cambridge educated?