[BBC News] Calls to harness natural energy

[Slim]

We already have a useless fucking eyesore at one end of our valley, and a second one stinking up the road running through us. Time to find another scapegoat for your white elephants.

 

Uh, have you been to port soderick beach lately?

 

 

Sorry for getting my days mixed up, but you got there in the end. 50 years was just a wild guess at a payback period. Bet it's longer than six months though - Jebus, if it were that quick we'd be MAD not to have wind farms all over the place - MAD I say!

I think I'm becoming a renewable convert - if only so the oil we save in power plants can go in my cars and bike!

 

We are mad not to have em. Pretty much everywhere else does. The paybacks pretty hard to calculate, because it depends on the cost of the alternative engergy. Payback time is coming down though as prices rise. Even if it took five years for that 6 months of constant wind to payback the turbine should last 20 years plus and is a renewable source of energy, so worth doing even at a higher cost today.

 

As for saving fossil fuels for transport, why not. When the rest of us are driving round in quiet, cheap and efficient cars that are somehow fuelled by renewables, you freaky fogies can help yourself to what's left!

 

 

1 Because wind and wave power are dependent on (you guessed it) wind and waves. Even on the IOM, these are by no means reliable.

2 Because nowhere else, with the possible exception of the Calf, offers anything like enough power-generating potential. And wave/tidal power has the same problem of inconstancy that renders wind-power impracticable. If it weren't for the massive subsidies, you wouldn't see a wind-power windmill anywhere.

 

Tidal power is constant. There's some superb prototypes like the one in the hebredes which uses a small airtight bunker with a turbine that's driven by the air forced in and out with the tide.

 

Subsidies help bring the payback time down sure, and they're certainly justified in setting up a desirable renewable infrastructure.

[Sebrof]

is there enough room at Sulby ? - take the smallest Welsh pumped scheme Ffestiniog - 360 MW ouput (energy storage maybe 1500MWhr) - has 2M cu m of stoarege falling through 200m - any Sulby scheme would all through at most 50m thus 90MW assuming same storage - say we want 50MW (about 50% of Island) for 5hr then we need about 1 M cu m (using the welsh scheme as model) - say 10m allowed variation in water level thus need 100,000 sq m of surface area (1km by 100m) - obviously you can play with figures but I suspect not really enough room but might work well if a tidal flow scheme was used as then the pumped storage need only run for say 2 hours of each tide

 

When full, Sulby would have a sq meterage of approx 6 sq kms, and an average usable depth of at least 20m.

 

S

[Sebrof]

Tidal power is constant.

 

What? Tides follow a sine wave. At high and low tide there is no power at all. Max power occurs in the middle.

 

All these alternative technologies depend on there being massive conventional backup systems. They are quite useless on their own, unless they have a way to store power. And that is where mountain reservoirs come in.

 

If you could find a more efficient form of renewable energy than wind-driven water pumps, there is no reason not to use them. But only a hydro system powered by a massive store of water offers a single, reliable, cost-effective, zero-emission, power-generation system.

 

S

[Frances]

When full, Sulby would have a sq meterage of approx 6 sq kms, and an average usable depth of at least 20m.

How ? - the existing reservoir is about 0.3 sq km - you would need equal volumes of upper and lower resrvoirs - assuming you took out all of the narrow Sulby glen between the 100 feet and the 400ft contour you would get at most 2 sq km but it is not clear houw you would get the upper reservoir - the island is about 500sq km thus you need 2% or more of Island area

[Sebrof]

When full, Sulby would have a sq meterage of approx 6 sq kms, and an average usable depth of at least 20m.

How ? - the existing reservoir is about 0.3 sq km - you would need equal volumes of upper and lower resrvoirs - assuming you took out all of the narrow Sulby glen between the 100 feet and the 400ft contour you would get at most 2 sq km but it is not clear houw you would get the upper reservoir - the island is about 500sq km thus you need 2% or more of Island area

 

If you look at the 260m contour on Google maps you will see what I mean.

 

S

[Frances]

I'm using the large scale footpath map - 260m = 800 ft contour line - between this and 600ft contour even taking in Druiddale + half of tholtywill plantation and putting a dam at tholt y will you would be pushed to get 4sq km - you still need a lower reservoir of similar volume.

 

It might well be worth looking at using one of the disused mines - an upper reservoir with a much greater drop (eg as modelled on Dinorwic)

[Sheriff Buford T. Justice]

How ? - the existing reservoir is about 0.3 sq km

 

No way. It's much bigger than that.

[Sheriff Buford T. Justice]

It might well be worth looking at using one of the disused mines - an upper reservoir with a much greater drop (eg as modelled on Dinorwic)

 

Now that gives me an idea. Why don't they hook a turbine up to the laxey wheel? That wheel is old proven technology which could generate eleccy without much investment.

[SteveP]

Do you need a lower reservoir at all?

 

Pump from the sea to a reservoir with wind pumps, and then return to the sea through a turbine.

 

 

 

OK, probably needs some bloody big pipes and some monster wind pumps....

[Frances]

How ? - the existing reservoir is about 0.3 sq km

 

No way. It's much bigger than that.

have a look at a map - unless my footpath map is very much out of date it occupies about 1/3 of the 1km sq OS 880370

[Frances]

Pump from the sea to a reservoir with wind pumps, and then return to the sea through a turbine.

Currently Sulby supplies drinking water - I realise that Douglas water tastes foul but I doubt if a salty taste would meet any standard

[Sebrof]

How ? - the existing reservoir is about 0.3 sq km

 

No way. It's much bigger than that.

have a look at a map - unless my footpath map is very much out of date it occupies about 1/3 of the 1km sq OS 880370

 

You could probably squash Sulby into a circle with a diameter of 400m. That gives an area of 1.26 sq km.

 

S

[Sebrof]

It might well be worth looking at using one of the disused mines - an upper reservoir with a much greater drop (eg as modelled on Dinorwic)

 

Now that gives me an idea. Why don't they hook a turbine up to the laxey wheel? That wheel is old proven technology which could generate eleccy without much investment.

 

Using my trusty slide-rule, I calculate that it would have to turn at 750,000 rpm just to light Onchan. I'm not sure that's practicable.

 

S

[Sheriff Buford T. Justice]

We have gears nowadays you know.

[Frances]

You could probably squash Sulby into a circle with a diameter of 400m. That gives an area of 1.26 sq km.

on my map there is a rectangle 300m by 700m with two tails east + west total 600m by 150m - maybe 0.35 sq km

a circle area is pi r squared r = 200m or 0.2 km 0.2km squared = 0.04 sq km x 3 = 0.12 sq km