[Apollo81]

gwnn, on Aug 11 2009, 03:56 PM, said:

Hey I just saw 'Who Killed The Electric Car'. Something changed since 2006? Or was the documentary just biased/false?

In 2007-8, gasoline went to $4.50 a gallon in the U.S., up from the $2-$3 range. Then the public/industry got all interested in fuel economy again.

[vuroth]

hrothgar, on Aug 12 2009, 08:26 AM, said:

Pump storage systems are extremely efficient

Interesting. Beyond the fact that it's enormously difficult to build a hydroelectric plant (due to non-greenhouse environmental impact), I would have thought that most plants run with a nearly full reservoir anyways. Aren't you creating an inefficiency in the first place by running the reservoir a bit lower, to allow for pumpback?

The long term outlook, I think, is that we are going to see electricity prices skyrocket in a way that will make us long for the gentle increases in gas/oil prices. It's really the only way bring alternatives to the forefront.

When that happens, people will be less excited about the Volt.

[hrothgar]

vuroth, on Aug 12 2009, 06:49 PM, said:

hrothgar, on Aug 12 2009, 08:26 AM, said:

Pump storage systems are extremely efficient

Interesting. Beyond the fact that it's enormously difficult to build a hydroelectric plant (due to non-greenhouse environmental impact), I would have thought that most plants run with a nearly full reservoir anyways. Aren't you creating an inefficiency in the first place by running the reservoir a bit lower, to allow for pumpback?

I don't think you quite understand how these systems work

Here's a classic example of a pump stoarge system.

Find a find a river that runs past a mountain
Cut the top off the mountain
Build a very large catch basin on top of the mountain
Build a second catch basin at river level
Build a set of pipes that connect the two catch basins
Fill the river level catch basin with water from the river

Each night, you draw power in from the grid and use this to pump water from the low catch basin to the high catch basin

Each day, you let the water from the high catch basin flow back down into the low catch basin and use this to generate electricity

The only reason that these types of systems make sense is that many electrical generation systems are quite inflexible. (My nuke plant is either running full blast OR it's not running at all). Worse yet, power consumption varies dramatically by time of day.

Adding a pump storage system means that we not longer need to waste the excess power that the nuke plant generates in the evening. We also get to build a smaller nuke plant than we'd need to meet peak demand during daylight hours.

(For what its worth, a second order Fourier series does a really good job describing Power Demand as a function of Time of Day though the difference between weekday versus weekends is rather annoying)

[Al_U_Card]

hrothgar, on Aug 12 2009, 12:45 PM, said:

vuroth, on Aug 12 2009, 06:49 PM, said:

hrothgar, on Aug 12 2009, 08:26 AM, said:

Pump storage systems are extremely efficient

Interesting. Beyond the fact that it's enormously difficult to build a hydroelectric plant (due to non-greenhouse environmental impact), I would have thought that most plants run with a nearly full reservoir anyways. Aren't you creating an inefficiency in the first place by running the reservoir a bit lower, to allow for pumpback?

I don't think you quite understand how these systems work

Here's a classic example of a pump stoarge system.

Find a find a river that runs past a mountain
Cut the top off the mountain
Build a very large catch basin on top of the mountain
Build a second catch basin at river level
Build a set of pipes that connect the two catch basins
Fill the river level catch basin with water from the river

Each night, you draw power in from the grid and use this to pump water from the low catch basin to the high catch basin

Each day, you let the water from the high catch basin flow back down into the low catch basin and use this to generate electricity

The only reason that these types of systems make sense is that many electrical generation systems are quite inflexible. (My nuke plant is either running full blast OR it's not running at all). Worse yet, power consumption varies dramatically by time of day.

Adding a pump storage system means that we not longer need to waste the excess power that the nuke plant generates in the evening. We also get to build a smaller nuke plant than we'd need to meet peak demand during daylight hours.

(For what its worth, a second order Fourier series does a really good job describing Power Demand as a function of Time of Day though the difference between weekday versus weekends is rather annoying)

The way the economy is going, the 7 day (two job) work week is making a comeback.

[vuroth]

hrothgar, on Aug 12 2009, 12:45 PM, said:

I don't think you quite understand how these systems work

No, I understood it well enough. First of all, I don't know that many existing hydroelectric generators are designed to take advantage of this system. Secondly, a very large driver is peak power - by playing with the levels of the upper reservoir, you're really playing with the peak power that the station can put out. Specifically, in this case, you're reducing it. This may well pay off in the long run, or maybe the difference is negligeable. Probably depends on the surface area of the upper reservoir.

Thing is, environmentalists (at least up here) go completely insane when you even suggest building a hyrdoelectric dam somewhere specific. Having two reservoirs would probably net you twice the opposition.

[hrothgar]

vuroth, on Aug 13 2009, 12:33 AM, said:

hrothgar, on Aug 12 2009, 12:45 PM, said:

I don't think you quite understand how these systems work

No, I understood it well enough. First of all, I don't know that many existing hydroelectric generators are designed to take advantage of this system. Secondly, a very large driver is peak power - by playing with the levels of the upper reservoir, you're really playing with the peak power that the station can put out. Specifically, in this case, you're reducing it. This may well pay off in the long run, or maybe the difference is negligeable. Probably depends on the surface area of the upper reservoir.

Thing is, environmentalists (at least up here) go completely insane when you even suggest building a hyrdoelectric dam somewhere specific. Having two reservoirs would probably net you twice the opposition.

You clearly don't understand this:

PUMP STORAGE IS NOT (NECESSARILY) THE SAME AS HYDROELECTRIC PLANT

The are lots of pump storage "pure plays".
These are batteries, plain and simple.
The are specifically designed to augment the peak capacity for the grid as a whole

[Gerben42]

Quote

The only reason that these types of systems make sense is that many electrical generation systems are quite inflexible. (My nuke plant is either running full blast OR it's not running at all).

Since I've read this twice already in this thread, as someone in the industry let me correct this. This is true for pressurized water reactors (which includes 100% of the French NPP and 2/3 of the American), but not for boiling water reactors.

Information about BWR

Quote

In 2007-8, gasoline went to $4.50 a gallon in the U.S., up from the $2-$3 range. Then the public/industry got all interested in fuel economy again.

Same here, although at the peak we were paying $9 a gallon... I think it's about 7 now.

[Fluffy]

Talking about excess voltage, yesterday another thunder collided in my home burning down my router, my hub and half of the internal components of my dad'd computer.

this is the third time a thunder gets home, this time the damage has been shared with my neighbour, but 8 years ago it burnt down 2 computers, the phone and several peripherics.

My house ain¡t taller than neighboud nor anything like, I wonder why the thunders always hit here, the only odd thing we might have is a big ammount of water under the house but I doubt it has anything to do :/

[hrothgar]

Fluffy, on Aug 14 2009, 05:14 PM, said:

Talking about excess voltage, yesterday another thunder collided in my home burning down my router, my hub and half of the internal components of my dad'd computer.

this is the third time a thunder gets home, this time the damage has been shared with my neighbour, but 8 years ago it burnt down 2 computers, the phone and several peripherics.

My house ain¡t taller than neighboud nor anything like, I wonder why the thunders always hit here, the only odd thing we might have is a big ammount of water under the house but I doubt it has anything to do :/

Lightning strikes are bad, m'Kay

You really might want to consider investing one or more decent surge protectors. (You can even find surge protectors that are design to shield the cable feed)

[Fluffy]

after last year I had one for dad's electricity supply, sadly the volt entered via the phone line towards the router and then to the computer by RJ45.

Wifi might be a solution to this I know.

[matmat]

Fluffy, on Aug 14 2009, 03:01 PM, said:

after last year I had one for dad's electricity supply, sadly the volt entered via the phone line towards the router and then to the computer by RJ45.

Wifi might be a solution to this I know.

is your house grounded?

That said, I work with a lot of hardware, and when there is a thunderstorm rolling through we make it a point to try to unplug everything from the walls that can be unplugged.

[Fluffy]

too much storms around here I think, or we are too lazy , but thank you.

grounded? it is attached to the ground!. Seriously, I don't know. In spain plugs do not have the middle ground plug you know?, just the 2 volts.

[matmat]

Fluffy, on Aug 15 2009, 10:16 AM, said:

too much storms around here I think, or we are too lazy , but thank you.

grounded? it is attached to the ground!. Seriously, I don't know. In spain plugs do not have the middle ground plug you know?, just the 2 volts.

I know.

http://en.wikipedia....i/Lightning_rod

[hrothgar]

As I mentioned originally, invest in a good surge protector.

They now have surge protectors for computer that will shield RJ45, CAT 5, you name it

[Elianna]

I've seen surge protectors that have a way to connect the phone lines through it.

And many have some kind of protection guarantee.

[Fluffy]

thx guys, I'll try to look around for those gadgets. It is not easy, we are almost Africa you know?