Do we REALLY have an energy crisiss ?

[The Natural Philosopher]

Gold?

Oil?

Copper?

you are an idiot if you think that.

[The Natural Philosopher]

Not at all. sacrificial screens?

[The Natural Philosopher]

Er..no. Doldrums is a word that means becalmed.. NO wind at all.

[stuart_noble]

I guess 99.9% would have taken that to mean the cost of manufacturing but, in true newsgroup tradition, there's always someone more interested in nit picking than contributing.

[Huge]

If you think the greenies will stand for putting genetically engineered weed into the sea, you're even crazier than I thought.

[Homer2911]

On Feb 16, 4:29?pm, David Hansen wrote: "Winds at 60m

Er. only when the wind blows, which is why there always has to be a standby, non-wind method of generation

[dennis]

Its not economics thats the problem. They are not carbon neutral. You aren't saving the planet by using solar voltaic cells so we are better off with them being too expensive (for now).

[dennis]

Did they have flight when they named them? There are winds just not in the sails.

[dennis]

Hmm.. Increasing the wind load, and the moment (taller towers) would significantly increase the costs of the foundations and the towers and the blades and the gear box and the gen set. I doubt if it would be cheaper at all myself.

It would be able to generate power on more days though.

[Brian Sharrock]

each day as the earth wobbles +23 odd , -23 odd degrees between winter and summer] Any incident-energy converting device; solar->heat; solar->electricity; is going to achieve maximum efficiency when the solar energy is striking normal (i,e, at ninety degrees both axes) to the converter. For a fixed collector the efficiency will daily rise/drop off in a sinusoidal manner. Efficiency of 1.00 at noon and 0.7 at -45/+45.

45 deg = three hours of sun's passage. So if you want to get an efficiency of 1.00 at nine'o'clock (am) and at three'o'clck (pm) you just make the collector wider. It'll be 'more' efficient at noon (the collector will intercept more of the sun's flux the wider it is] It's simple and doesn't require a tracking system which will require maintenance. Engineers will appreciate that the 'good old sine wave' is reasonably 'flat' across the top dropping off rapidly above/below 45 deg. Why make things complicated?

[David Hansen]

On 17 Feb 2007 02:30:05 -0800 someone who may be "Homer2911" wrote this:-

I note that your comment has nothing to do with the bit of my posting that you quoted.

However, all forms of electricity generation need to be backed up. Large plants are a particular problem because when they or a line fails there is a sudden large hole in the electricity system that needs to be filled. When the second largest coal fired power station in the UK suddenly failed a few weeks ago there was a big hole to plug.

Nuclear stations cannot provide any sort of backup (other than of the longest term) as they are far too slow to react. Anyway several of them are not working too well at the moment. However renewables, in the form of hydro stations, can react incredibly quickly and played a major part in keeping the lights on. Some are held in immediate response mode, ready to supply full output in less than ten seconds yet produce no carbon dioxide while waiting. Hydro stations which are stationary can provide full output in about 90 seconds (somewhat longer if they still have old controls). Straight gas turbine stations can provide full output in about 120 seconds.

As for wind, like any other form of generation it needs to be backed up. However, this is a lot easier because the wind does not suddenly start and stop blowing, but rather varies in intensity over a period. In the two timescales that matter in the UK electricity system, one hour ahead and a few days ahead of real time, wind forecasts are already highly accurate. Within one hour ahead any excess or shortfall in wind, which is relatively minor, is dealt with by the normal balancing mechanism that is operating anyway.

At current prices no expensive changes to the electricity system are necessary unless wind exceeds about 20% of generation.

This has all been studied in great detail and it is gathered together at

which is worth studying before commenting too much on the subject.

[The Natural Philosopher]

Manufacturing means taking war materials and turning them into something.

The value add may drop, but you can't drop below the material costs..and materials other than oil are in short supply.

Electronics uses oil based plastics, ut uses gild, copper, tin aluminium. It uses arsenic, gallium, and all sort of other weird stuff.

None of which are free..

[The Natural Philosopher]

No, for long periods there are no winds in the sails at all.

A typical sailing ship would be nearly as tall as your average windmill.

[The Natural Philosopher]

Frankly the greenies are as big a danger to the planet as GW BUSH.

[David Hansen]

On Sat, 17 Feb 2007 18:18:58 -0000 someone who may be "dennis@home" wrote this:-

All true. However, there are also fewer of these things because there are fewer turbines.

Doubt it as much as you like. However, I'll continue to believe that those building wind farms have gone for larger turbines because they are more cost effective.

[dennis]

What have windmills got to do with it?

[dennis]

They probably are.. for the reason I stated.. they provide some power on more days than the small ones.

[The Natural Philosopher]

Power goes with the square (or the 4th power - I forget which) - of the blade diameter.

Since much of the cost of the windmill is NOT related to its size, big ones are more cost effective.

[Ed Sirett]

Essentially the square, but due to winds speeds begin a bit higher as yu get away from the ground the larger ones scale slightly more than by the square.