Turn off your rig - Earth Hour, March 31st 2012 20.30-21.30 (your local time)

[BurtW]

Talked to my friend who is an electrical (power) engineer and works for a power company here in Colorado.  He agreed somewhat with me but I did learn some new facts.

If demand drops they will turn off the production that is easiest to turn off first.  So here is what will happen:

1) They will turn off all of their solar energy production.  These can be turned off with the flip of a switch.
2) They will turn off all wind generation stations.  These can be turned off one by one as the demand drops.
3) They will turn down (not off) their most efficient combined cycle natural gas generation plants - these can be turned down to about 60% without much of a penalty when restarted (reheated)
4) They will turn down the fuel flow to other older natural gas plants.
5) They will turn down the fuel flow to the coal fired plants.
6) If the drop it enough then they might consider turning down any nuclear power plants they may have.

Notice that 3) through 6) will never get turned off, just down, due to having to get them back up to temperature if turned off.

So, the consequnce of Earth Hour^TM is to shut off all the cleanest and most expensive power production and use the dirtiest cheapest power production.  Great for the power companies.  Maybe they are sponsoring it?

I was wrong about waste.  They will do all of the above to match the production to the demand.  There is very little waste during a smooth event like this.  A total drop or a huge spike is different.  So, unless we get everyone to turn off everything he expects just about zero effect, asside from those measures described above.

[SgtSpike]

Since wind and solar power generation is essentially free, why do they even turn it off?

[JusticeForYou]

Talked to my friend who is an electrical (power) engineer and works for a power company here in Colorado.  He agreed somewhat with me but I did learn some new facts.

If demand drops they will turn off the production that is easiest to turn off first.  So here is what will happen:

1) They will turn off all of their solar energy production.  These can be turned off with the flip of a switch.
2) They will turn off all wind generation stations.  These can be turned off one by one as the demand drops.
3) They will turn down (not off) their most efficient combined cycle natural gas generation plants - these can be turned down to about 60% without much of a penalty when restarted (reheated)
4) They will turn down the fuel flow to other older natural gas plants.
5) They will turn down the fuel flow to the coal fired plants.
6) If the drop it enough then they might consider turning down any nuclear power plants they may have.

Notice that 3) through 6) will never get turned off, just down, due to having to get them back up to temperature if turned off.

So, the consequnce of Earth Hour^TM is to shut off all the cleanest and most expensive power production and use the dirtiest cheapest power production.  Great for the power companies.  Maybe they are sponsoring it?

I was wrong about waste.  They will do all of the above to match the production to the demand.  There is very little waste during a smooth event like this.  A total drop or a huge spike is different.  So, unless we get everyone to turn off everything he expects just about zero effect, asside from those measures described above.

So when, Ideology meets Reality = FAIL

But 'maybe' the OP had 'shorted' the stock of the Solar and Wind power industries. Hmm...

[JusticeForYou]

Since wind and solar power generation is essentially free, why do they even turn it off?

Simple,

It is the easiest to turn off and on. Efficiency over time.

[SgtSpike]

Since wind and solar power generation is essentially free, why do they even turn it off?

Simple,

It is the easiest to turn off and on. Efficiency over time.

But if it's free to generate electricity with wind and solar, why does it need to be turned off, ever?  What good does it do to turn it off?

[BurtW]

It is symbolic.  Assuming 10% participation they will hardly notice it.  If you get 50% participation they will handle it just fine.  If you were to get 90% participation (including real energy hogs like electric furnaces used to make steal, not just consumers, lights, etc.) they would have to scramble to handle the load swing.  It is only one hour.  It is per time zone from what I understand so it does not even affect the entire grid all at once.  Excess production may just be shipped off into another time zone.

Symbolic.

[BurtW]

Since wind and solar power generation is essentially free, why do they even turn it off?

If solar and wind is free why isn't everything running on solar and wind?  The reason it that is it not free.  Wind has moving parts.  They wear faster under load so free wheeling or stoping the blade reduces wear.  The solar pannels themsleves wear at about the same rate whether producing or not (they do wear out) but not producing reduces wear on other components - especially the inverters.  Solar pannels produce DC and it has to be converted to AC.  Those inverters - especially huge comercial inverters - do wear when running and do not wear when turned off.

Solar and wind are not free.  In fact they are the two most expensive ways to produce electricity we have.

EDIT:  my comment on solar pannels applied to stationary pannels, not trackers.  Solar pannel wear is directly propotional to total solar flux.  So if a tracker is turned away from the sun to turn it off then the wear on the pannel itself can be mitigated.

[SgtSpike]

Ok, good points BurtWagner, thanks for answering.