Questions tagged [electrical-grid]
19 questions
20
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5 answers
Why does it take so long to restart a nuclear power plant?
I have heard a couple of times that an operating nuclear power plant which was shut down (non-emergency; e.g. for a regular check) needs over 24 hours (up to 72 hours?) to get up running again.
Why does it take that long?
Martin Thoma
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13
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7 answers
What are the disadvantages of concentrated solar thermal power?
Concentrated solar power looks on the surface to be an excellent source of grid power. It's sustainable, has no obvious waste products to deal with either during construction or operation, and with thermal storage it can generate power at night or…
Stephen Collings
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4
votes
1 answer
What's the history of the 345 kV voltage level in power transmission?
I'm interested in the history of the 345 kV power level for high voltage transmission in the United States. I've got two (and a half) questions:
According to this source 345 kV was first applied in 1953 by American Electric Power. Who has developed…
Tanner Steinbuch
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4
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4 answers
Why shouldn't we put high voltage cables physically underground?
sorry for the odd title. We're working on a project to find a cheaper and safer way to install high voltage power lines in the Scottish highlands. One of my group mates had a really cool idea to instead of actually digging underground, you could…
masiewpao
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3
votes
2 answers
Why are both conductors in a High Voltage Direct Curent powerline isolated from ground?
Picture of a High Voltage Direct Curent powerline (HVDC line) on the Læsø Island, Denmark (from Google Street View):
We can observe that there are 2 conductor cables, and that both are insulated from the tower (which is grounded). Because the line…
Bregalad
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2
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Why 'battery storage power stations' use mainly liion batteries?
As I understand liion batteries have lower lifetime, than LiFePO4. Why would such big stations use liion batteries then? Wouldn't replacement cost large amount of money? And how long those liion battery storage power stations last, before batteries…
Name
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2
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1 answer
What is the specific issue with frequency fluctuation in the grid?
I understand that if supply and demand are not in equilibrium synchronous generators make the difference by increasing or decreasing their rotational energy - thus changing the electrical frequency in the grid. It is usually noted that a frequency…
Akerai
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2
votes
4 answers
Why aren't gravity batteries everywhere?
The problem of energy storage, especially with regard to renewables, remains unsolved. Or at least there do not seem to be any popular solutions.
Why not gravity batteries?
I love the idea, and they look like a beautiful and effective approach to…
SuaveSouris
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1
vote
2 answers
Expected power increase when replacing old (>20 years) wind turbines
Plenty of onshore windfarms around the world are reaching the 20-25 year old mark and thus may be on the process of repowering.
Let's say an old wind farm has 10 rotors of 0.5 MW each (total power 10x0.5 = 5 MW). During repowering you may replace…
Brenlla
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1
vote
2 answers
What fraction of energy is typically lost in transmission over power lines?
Energy transmitted via power lines necessarily undergoes some degree of attenuation. The question is, how much?
This source, screencapped from this video, says:
But, I've heard via word-of-mouth from a source I previously trusted that losses can be…
DJG
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1
vote
2 answers
What, roughly, are the characteristics of nuclear power in grid management?
Electric grids are volatile: As there's close to no storage capacity, power in must equal power out all the time.
One part of the management toolset is the various power sources attached to a grid. For the most part, it's relatively straight forward…
1
vote
2 answers
What happens if an entire country turns off all lights and electric devices during peak consumption hours?
I've been reading about smart grids but I studied Computer Engineering and my already limited knowledge of power systems is very rusty. I keep hearing that traditional power stations have to adjust production to match demand, but I don't understand…
Ariel
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1
vote
2 answers
Simple clarification about EV charging
After reading some docs about Electric Vehicles (EV), I learned that there are 4 differents charging modes.
For example, let's consider a slow recharge, where EV is connected to a single-phase domestic wall socket: its battery will absorb 16 A, so…
rainbow
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1
vote
0 answers
How to solve power surge caused by curing oven PWM cycle?
I have a Despatch LBB 1-69 lab oven in my shop. It is a single-phase, 110-volt, 30-amp unit. It is wired to a 220 volt, 2-phase, 40-amp panel (on a single 110 volt phase), which is fed by the 100-amp main service. All wiring is appropriate or larger…
Andrew M
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1 answer
At what cold ambient air temperature will power lines fail?
I'm wondering just how cold it would have to be before electric power can no longer flow through overhead power lines. I know power lines generate a certain amount of heat just as a side effect from electric current, but I don't know if sucking off…
DrZ214
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