TOT Wave power

[alan_m]

While sitting in a long line of traffic today I was listening to the radio and someone was promoting wave electricity generation and indicated that a very successful wave power generator had been installed in Gibraltar.

I took the opportunity to google it. It is very impressive!

I cannot be sure, but I think the spokeswoman said it needs the right kind of waves and is removed (raised up) from the sea in storm conditions. Intermittent power generation again? Also she said this is the way forward, given sufficient subsidies :)

[alan_m]

Video

[Tim+]

Well that true of any energy generation system. ;-)

Tim

[Chris Hogg]

Wave power is a proxy for wind power. No wind = no waves. So it's intermittent. Might be OK for small isolated communities who don't have access to other sources of electricity, but it will still need batteries or other back-up to get it through the doldrum times, which will be many and long-lasting.

There was a grand scheme which constructed a test-socket for wave-power a few years ago, some ten miles NW of St. Ives in Cornwall. It was intended to act as a pilot-scale facility to assist wave power development. £42 million was spent, but not a milliwatt of electricity came ashore.

and in general Eventually it was sold to a Swedish company for testing floating wind turbines. i.e. not wave power.

Not an overwhelming success. Just yet another renewable energy failure. How long will it take before the gullible investors get wise?

[Jethro_uk]

Also, it tends to be localised, so steals energy from the ecosystem further down the line. Which might have quite subtle but deleterious changes over time. Much like putting a sodding great solar panel over a field of crops and then wondering why they ain't growing. (And yes I know there are schemes to put solar panels over crops ....)

[Brian Gaff]

Well the two competing methods were the kind of dome things fastened to the see bed where the air pressure under the dome varied with the waves as they passed by and this was used to pressurise some kind of hydraulic feed for generation. The other of cours is salters Duck, basically an upside down wing shape that has an offset c of g so nods as the waves pass, again used to pressurise a hydraulic feed. Of course Tidal power would seem to be the way to go, there is a big one in France that I've crossed, but the snag is that the environment is affected and things silt up differently as you impede the water passing back and forth. There was a plan for an underwater one between some of the channel isles, called the race, where the tide gets squeezed, but a small scale trial sowed it would upset many species of filter feeders which rely on the tidal movement being fast, and it was always being silted up and needing to be dredged. Brian

[Joe]

There must be big problems. I saw this kind of thing reported on Tomorrow's World at least half a century ago.

[Joe]

Like the friction of tides over rocks, done on a large scale it will slow down the Earth's rotation...

[John J]

Just after Zero Energy Thermonuclear Apparatus was going to make power so cheap it wasn't worth metering?

[The Natural Philosopher]

More total ecobollox. Its expensive intermittent and environmentally destructive. Just like all other 'renewable energy'.

[The Natural Philosopher]

They don't care as long as government subsidies prop it all up.

[The Natural Philosopher]

The killer comment for those not blessed with a deep knowledge of engineering and economics was passed to me by a technician years ago.

"If it were that good, everybody would be doing it"

Ex of government interference, any technology has to be cheaper than the competition or more effective.

That is why renewable energy is subject to total government interference.

[Tim Streater]

In the scheme of things, it's not big at all. Not capable of being scaled and needing backup anyway. And as someone has already said, if it were any good there'd already be lots of them worldwide. It's not as if it's a new idea.

[alan_m]

On 09/06/2023 07:40, Chris Hogg wrote: sidies :)

The back story mentioned was that Gibraltar had no space for solar and didn't want to disfigure the iconic rock with ugly wind turbines, hence the wave power plant :)

[The Natural Philosopher]

No renewable energy is a new idea. Windmills go back to the Dark Ages, and should be returned there.

Solar panels at least have some claim to depend on quantum physics, but in the end the very nature of sun, wind, tide and wave, is what gets you, There's not that much energy in any of them, so your structures to collect it have to be big, and hence of huge environmental impact and cost, and the energy isn't there all the time, which means that most of the time all your plant is lying (partially) idle, and something else has to take its place. Doubling or trebling capital costs.

And they *all* ultimately depend on the only energy there is in the universe. Nuclear power.

Why not stop pretending, cut out the middle man and build cheap compact environmentally friendly reactors instead?

Renewable energy is the most expensive and inefficient way to harness nuclear power it i s possible to devise.

[The Natural Philosopher]

Why don't they pop in a couple of small modular reactors instead?

[Chris Hogg]

They should put tidal turbines into the Straits of Gibraltar. The currents must be quite strong as the tides ebb and flow into and out of the Mediterranean, even if they only produce useable energy for three hours, four times a day. At least they would be more reliable than wave power, and seem to be working OK in the Pentland Firth, albeit with the same constraints.

[Paul]

Is there an actual "finished design" for one of those SMR yet ?

I see sketches, but no "examples".

Paul

[John Rumm]

In many nuclear power subs and ships yup... not fully packaged into a production line ready product as yet though.

[Tim Streater]

Not sure the water flow actually changes direction. I thought there was a constant flow *into* the Med (modulo the tide a bit) due to much greater evaporation aover the whole Med than the Atlantic.