Don't know where it should go? Stick it here!

Message boards : The Lounge : Don't know where it should go? Stick it here!
Message board moderation

To post messages, you must log in.

Previous · 1 · 2 · 3 · 4 · 5 · 6 · 7 . . . 38 · Next

AuthorMessage
Profile Dave
Help desk expert

Send message
Joined: 28 Jun 10
Posts: 2516
United Kingdom
Message 100403 - Posted: 22 Aug 2020, 5:57:11 UTC

Plus I pay a lot more for power than you I suspect.

I pay about $70 a month for combined bill for gas and electric. Plus some wood I buy in during the winter. Have got about half what we need for coming winter for free and all of what we will need for the following one once I have it all cut up and split. Our electricity use is about 7KWH/day in winter and about 4 in summer plus whatever comes off the panels.
ID: 100403 · Report as offensive
robsmith
Volunteer tester
Help desk expert

Send message
Joined: 25 May 09
Posts: 1283
United Kingdom
Message 100404 - Posted: 22 Aug 2020, 7:10:13 UTC

I've been there twice, one of those times inside it in the visitor centre, but I've never seen it power up. I wonder if they make sure there are no boats nearby first.


The visitor centre & tour has tamed down over the years - the first time I went on a public tour must have been about 1970 one could walk around the turbine floor. The next public tour was quite a few years later and all one could do was stand in an observation gallery part the way up one end wall and look down and along the turbine hall. Neither was anywhere near as good as the couple of private (professional) tours which were basically "access all areas".
They rarely do a full rate turn on due to the disturbance it causes to Loch Awe - there is a stilling pond at the outflow which copes very well at full power, but at full rate less so. I can't remember what the normal run-up time is, but 10 minutes lurks in my mind (against 2 minutes for a full rate run-up). Even at 10 minutes you have to be very lucky to see a start as they are normally only once a day just before the start of peak demand in the morning. You might be able to see this as a slight increase in mains frequency, but given the way that moves I doubt it.

I'd love to see the guts of one of the really big stations like the one down the road from Keith - three times the power output from a very similar head of water. (Keith - what's the start-up time on that one?)
ID: 100404 · Report as offensive
Profile Keith Myers
Volunteer tester
Help desk expert
Avatar

Send message
Joined: 17 Nov 16
Posts: 863
United States
Message 100405 - Posted: 22 Aug 2020, 7:31:41 UTC

I pay from $400-950 a month for my power, at least that was for last year running 5 computers. Should be much less this year, the last 3 bills were for $138, $271 and $374 now that I am only running 2 computers. Should peak out for the next two bills around $450 -$500 I think

I can't remember how fast the startup of the Castaic Power plant is, but it is fast. It is an important generator for the Los Angeles area. I was amazed at the size of the penstocks which I've seen historical photos of a person standing inside the mouth of one next to a pickup truck for scale and they are huge. The volume water coming through is massive. I've been on a ski boat at Pyramid Lake when then start letting water out for generation and the lake level drops precipitously fast.
ID: 100405 · Report as offensive
robsmith
Volunteer tester
Help desk expert

Send message
Joined: 25 May 09
Posts: 1283
United Kingdom
Message 100406 - Posted: 22 Aug 2020, 8:07:22 UTC

Thanks Keith - I bet it was a rapid drop in level. That feed lake isn't very big (in terms of generating hours of water).....

Re-reading my old notes Most (all?) modern (post 1950s) pumped hydro schemes use a dry run-up to speed things up. Simply put, they turn off the feed valves from the penstocks, open the drain valves and allow the turbine to empty (pumping water out into the lower lake if necessary), run the turbines up to speed in air then open the feed valves in a matter of seconds - obviously there is some air pushed out during this and one has to assume that this is what causes the massive amount of spray I encountered during a max-rate start.
ID: 100406 · Report as offensive
Profile Keith Myers
Volunteer tester
Help desk expert
Avatar

Send message
Joined: 17 Nov 16
Posts: 863
United States
Message 100413 - Posted: 22 Aug 2020, 23:36:28 UTC - in response to Message 100411.  
Last modified: 22 Aug 2020, 23:41:11 UTC

There is a lot less current demand on the standby generator that is used to spin up the main bi-modal generators. Plus a lot less strain on the impellers when the big slug of water hits them at 0 rpm and you have to overcome the inertia of starting that mass moving.

At the Castaic Power plant they have a large surge tank that holds a volume of water. It is used to start the main generators while the water in the penstock gains speed.


Visible from Templin Highway and normally mistaken for a water tank, the surge chamber sits at the south end of the Angeles Tunnel. The surge chamber is 120 feet in diameter and 400 feet high with 160 feet visible above ground. The chamber is there to relieve excess pressure in the tunnel and penstocks if the plant were to experience an emergency shutdown of its generators. It also supplies water for quickly starting the plant's generators while water gains speed in the 7 mile long Angeles Tunnel.
ID: 100413 · Report as offensive
robsmith
Volunteer tester
Help desk expert

Send message
Joined: 25 May 09
Posts: 1283
United Kingdom
Message 100414 - Posted: 23 Aug 2020, 6:24:55 UTC - in response to Message 100411.  

Several, but if you care to think of all the reasons these two come out near the top of the list:
It's easier to stop water entering the turbine chamber than reverse its flow
The turbine can be sped up more quickly in air than in water
ID: 100414 · Report as offensive
Profile Dave
Help desk expert

Send message
Joined: 28 Jun 10
Posts: 2516
United Kingdom
Message 100419 - Posted: 23 Aug 2020, 8:54:27 UTC - in response to Message 100410.  

How much power do you use for computers?


Not a great deal. I have a core2 duo and an old 4 core laptop and that is it at the moment. The laptop runs 24/7 but the desktop is off most nights and only running during the day when I have solar electricity.
ID: 100419 · Report as offensive
Dr Who Fan
Avatar

Send message
Joined: 10 May 07
Posts: 1328
United States
Message 100461 - Posted: 25 Aug 2020, 2:45:03 UTC
Last modified: 25 Aug 2020, 2:46:14 UTC

And the winner of the award for the most inappropriate slogan for 2020 goes to...KFC
The home of the world’s favorite fried chicken ‘fesses up to slogan being a bit ‘off’... for now...

The use of It’s Finger Lickin’ Good will be paused in advertising around the globe from today.
...
And for all those fans, don’t worry - the slogan will be back. Just when the time is right.
ID: 100461 · Report as offensive
robsmith
Volunteer tester
Help desk expert

Send message
Joined: 25 May 09
Posts: 1283
United Kingdom
Message 100467 - Posted: 25 Aug 2020, 14:50:50 UTC

American irony?????
ID: 100467 · Report as offensive
Profile Gary Charpentier
Avatar

Send message
Joined: 23 Feb 08
Posts: 2462
United States
Message 100474 - Posted: 26 Aug 2020, 4:45:23 UTC - in response to Message 100467.  
Last modified: 26 Aug 2020, 4:47:34 UTC

American irony?????

I think, it is an excuse to find a fresher tagline.

Covid finger lickin' virus.

"A pound of salt and 10 herbs and spices?"

"Chickens have three breasts!"

"Half the meat, twice the price!"

"Extra Grease or Double Burned?"

"The Colonel is a cross dresser!"

I'm sure they will come up with a tagline to go with their swill.
ID: 100474 · Report as offensive
Profile Dave
Help desk expert

Send message
Joined: 28 Jun 10
Posts: 2516
United Kingdom
Message 100475 - Posted: 26 Aug 2020, 5:03:32 UTC

Teacher: Two negatives can make a positive but two positives can never make a negative.

Voice from back of class: Yea, right.
ID: 100475 · Report as offensive
TimeLord04
Avatar

Send message
Joined: 21 Nov 13
Posts: 641
United States
Message 100483 - Posted: 26 Aug 2020, 19:11:34 UTC - in response to Message 100474.  

American irony?????

I think, it is an excuse to find a fresher tagline.

Covid finger lickin' virus.

"A pound of salt and 10 herbs and spices?"

"Chickens have three breasts!"

"Half the meat, twice the price!"

"Extra Grease or Double Burned?"

"The Colonel is a cross dresser!"

I'm sure they will come up with a tagline to go with their swill.

AND:

"Do you want gravy printed with that?"


TL
Have TARDIS, will travel...
Come along K-9!
Join Calm Chaos
Pluto is still a planet
ID: 100483 · Report as offensive
Previous · 1 · 2 · 3 · 4 · 5 · 6 · 7 . . . 38 · Next

Message boards : The Lounge : Don't know where it should go? Stick it here!

Copyright © 2024 University of California.
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.