Scottish Wave Energy Plans Move Forward

It's been a long time coming (2007, 2005, and 2002 respectively), but the project to harness wave energy off the Scots coast is finally coming together. Reader krou writes: "The BBC is reporting that ten sites on the seabed off Scotland in Pentland Firth and around Orkney have been leased to energy companies with the hopes of generating wave and tidal energy. 'Six sites have been allocated for wave energy developments potentially generating 600 megawatts of power and four for tidal projects, also generating 600 MW.' The leases were awarded to SSE Renewables Developments, Aquamarine Power, ScottishPower Renewables, E.ON, Pelamis Wave Power, OpenHydro Site Developments, and Marine Current Turbines. Scotland's First Minister Alex Salmond said that 'These waters have been described as the Saudi Arabia of marine power and the wave and tidal projects unveiled today — exceeding the initial 700MW target capacity — underline the rich natural resources of the waters off Scotland.'"

Comments

The big question

[BadAnalogyGuy]

Removing this energy from the ocean may cause an imbalance in the gravitational effects between the Earth and the Moon. Well, not imbalance, but rather a rebalance.

If we cause the Moon to move away from our planet, we lose both our astrodebris sweeper and more importantly our tide maker. Anthropogenic effects are real, and I'm not sure I'm happy to see the deliberate removal of energy from the ocean without further study on longterm planetary effects.

Re:The big question

[Al's Hat]

The electricity generated will power devices that shed heat, the heat adds to global warming, the global warming increases intensity of hurricanes and cyclones, the hurricanes and cyclones stir the oceans...no problem!

Re:The big question

[dbIII]

Were that I be so wise as to deduce the secrets of Creation by gazing upon the Scottish shore.

That is what a lot of science is - looking at things to work out the secrets of creation. The whole religeon vs science thing is from people with no clue about either.

Re:The big question

[MichaelSmith]

The tidal bulge on the Earth actually drags on the moon and increases its orbital velocity. It does this because the rotation of the Earth drags the bulge ahead of the sub-lunar point. The gravitational field of the bulge attracts the moon so the earths rotation slows as the moons orbital velocity increases. Eventually we will be tidally locked like Pluto and Charon and tides will be much smaller.

My preferred solution is to dump a whole lot of nuclear waste on the far side of the moon and turn it into a bomb. I wanted my proposal implemented by 1999 but not enough people saw the gravity of the situation.

Re:The big question

[Netssansfrontieres]

We sometimes forget just how heavy water is, or how much energy ocean waves carry.

Some time ago, I did some statistical analysis of wave heights in Scapa Flow, not far away from the site proposed here in northern Scottish waters. It has very steady, large swells.

Imagine a wave (or swell) of 10m peak height, extending 2 km across, and 50m front-to-back. That's a nice 0.3 * 10^6 kg of water ... move it forward at 30kph ... repeat every 10 or 20 seconds, and you've got 10^9 Joules/second, about 1GW. For the surface wave. (More energy is transferred more steadily by sub-surface currents.)

Lunar tidal flows are so much larger than these that the prospect of drawing enough energy from open waters to do anything to earth - moon movements seem to be off by many orders of magnitude.

Full disclosure: I used to be a pretty good physicist, but that was a long time ago.

Re:The big question

[Kentari]

You calculated the kinetic energy of a mass of water moving forward at 30kph. In a wave water is not moving forward at the wave speed, but rather gently in an elliptic trajectory. I gather you used 10m as amplitude and not crest to through height.

The energy flux of waves is given by the formula which you can find on this wikipedia page. A 20m (crest to through) wave with a period of 10s over a lenght of 50m gives you 20MW of wave energy. Still a lot, but almost 2 orders of magnitude less than 1GW.

Transmission

[moosesocks]

Where's this power going to? Is there a transmission grid in place to take it to a populated area that could use an extra 600MW? Orkney's in the middle of ^*$&ing nowhere.

Re:Transmission

[lilo_booter]

Depends where you are - if you live in Orkney, it's not remote, everywhere else is :-).

Re:Transmission

[drsquare]

Where's this power going to? Is there a transmission grid in place to take it to a populated area that could use an extra 600MW? Orkney's in the middle of ^*$&ing nowhere.

No, they're just going to fire the electricity into the air. They have no plans to actually deliver and sell it. You see, people who invest in this sort of thing simply hate money.

It figures

[PPH]

If it involves messing around with waves, there's usually a Scottsman involved somehow.

Re:We Are Swimming in Clean Energy

[shermo]

I'm glad that blog has the word 'science' in its title, otherwise I would think it was a load of made up nonsense.

Re:Should have an advantage over wind..

[MichaelSmith]

Not only that but by converting gravitational potential energy into heat we create photons which transfer momentum to the moon and push it away faster. I propose that all future lunar landings be on the far side to compensate.

Re:They're missing some....

[fm6]

Scotty, I'm really tired of that cliché. You're fired.