Nice video. Explains a lot. I remember before I went to DC for the first time, my boss told me to notice how all the power lines in the city were underground
Overhead cables not being insulated or very thin insulation are kept cool by passing air, underground with thick insulations cables heat up when passing a lot of current for lengthy times thus resulting to very decreased life of the plastic insulation.
Underground is nice but the cost and thermal ampacity limits restrict it's economical ideployment. ACSR open air conductors are far better (thermally and deployment cost) Undergrounding. Makes more sense for 12/21 KV in developed areas. Our local utility has an ongoing battle keeping 30+ year old direct burial cables operating. When we lose an aerial 12KV feeder it's less than an hour for restoration... RU feeders can be several hours to locate the fault and dig up the line...
SHORTER LIFE EXPECTANCY?! Overhead lines change temperature faster, change temperature MORE, are exposed to wind, ozone, UV, water, ice and snow. They are exposed to MORE animals, especially squirrels and birds Loss-costs are, on average, 2.8% for underground, vs 37% for overhead. 70% of line failures are weather-related, 11 percent are animals on overhead cables/poles/transformers... Underground cables bring those externality risks down by at least an order of magnitude!
PhrontDoor you are wrong. AC lines can't be buried more than 40 miles. You are talking about physics contacts to the line but the reduced life of underground lines is because the electric power pass through the ground. Only DC voltage can pass to long distances of water/ground and have much more efficiency than AC.
@PhrontDoor I think you have mixed up life expectancy with risk of temporary failure. An overhead line will have a much higher risk of temporary, easily fixed failures caused by animals shorting to ground, or a tree falling on coming in contact with the line. These types of short term failures occur much more frequently on an overhead line, but they are easily resolved(most of the time), an underground line will have much lower risk of small scale failure, however the wire will age much faster due to water ingress and other conditions when compared to an overhead line, so the entire cable will have to be replaced after a shorter time.
Anywhere in the US, as I know it, don’t allow underground transmission lines. I think it’s because of the big Electromagnetic Field (EMF). Underground lines tend to be below 20 feet below the surface. When we walk near or above one of those lines, we can be severely harmed by the EMF radiation. *Did you know?* Transmission table Voltage = radiation (EMF) 20-50kV = 22-77ft 50-90kV = 77-103ft 90-99kV = 103-119ft H-shape frames ••••••Transmission level 2••••• 99kV-100kV = 119-121ft 100kV-130kV = 121-199ft 130kV-190kV = 199-213ft 190-199kV = 213-222ft Transmission poles (200kV-210kV) and pylons (211kV+) •••••Transmission level 3••••• 200-210kV = 229-268ft •••••(Pylons) Transmission level 4••••• 211-240kV = 280-344ft 241kV+ equals 351ft+
Here in Florida, underground transmission lines will never happen. Floridian rate payers don't want to pay the extra cost. If anything, FPL is upgrading the wooden transmission poles to steel ones.
I live in Florida, and nearby a 200,000+ volt three phase line was buried to avoid having to cross a scenic view over a waterway near the coast. While they were at it they also buried a set of normal distribution lines as well. In Memphis Tennessee, ALL of the transmission lines and distribution lines are buried in the downtown area.
Life expectancy ? see what storms & fires do to your local town and just ask the insurance companies how much the damages & repairs cost vs going underground for a little added cost up front and nowadays with better materials and equipment even internal grounded expansion fittings are watertight eliminating the cost of bonding jumpers and the risk of failure and safety for longevity. Check out a company called Bams fittings and see the new technology that's available now and one of the reasons we should continue to go underground for sustainable energy vs overhead. And yes there are certain areas that need to continue with overhead this we know. But if you're gonna go underground please use new technology not old grounding technology it'll also save money and time installing it to help the bottom line in cost. Research it
But for outside powerlines you need to build and install some "steeltowers" and it needs a lot of time to install the lines in that height. I could imagine doing a simple installion for underground lines. No underground concrete "houses" to join the lines. One machine does it all. 1. escavate 2. lower powerline 3. put concrete in 4. join with the next line 5. cover, close and finish. How can that cost more ? And why underground lines have just the half lifetime like the outside lines ? Should be inverse or not ? Undergroundlines are safe from wheater, air, water, wind and sun.
peter schiller its because the way AC current works. The line is a conductor and also a capacitator, when you change the voltage (and you do it 60 times per second on US power grid) you need to recharge the cable 60 times a second and only after that you can have power on the other side of the cable. With earth you have serious issues with reactance between the line and the ground. In the air this issue is 100 times less relevant. All transmission lines between islands and mainland are with DC current because of that
Voltage is the pressure/flow of electricity pushed by a circuit the thing you have to worry about killing you is amps. Higher the voltage lower the amps higher the amps higher lower the voltage. Essentially how electricity flows over long distances
Main reason is urbanization. Almost impossible these days to build HV OH lines in big city/metro areas. Industrial areas are another example where HV UG cable are used from HV S/S to the industrial complexes. The use of UG HV cable is only increasing with time; will be more with the increase in DER (distributed energy resources) as we have seen in Europe.
Overhead transmission lines running near houses causes leukemia in the people of those houses, especially kids. Under ground transmission lines can be shielded and made safer but the power company doesn't want to afford the cost.
i do not belong to the understanding minds, but iam just depart from that , kindly allow to express our pain general electricty can be done underground y basic electricity supply highly a great pain to making green , unless underground electricity wire comes only then we can think of plantation and support life expectancy of human with oxygen today oxygen tax will be the future business in india solar and electric vechile still not in practice how for india still failing to impose y dealer and distributor still places to make business with fuel vechil the prices of solar vechile itself raised that is shame to indian gdp or lower end state like southern state gdp country shaming livilyhood when certain amount of oxygen itself insufficent in the earth
it take up space too . planes that need to land in emergency can't do so because of stupid tall towers in their ways , expecting them to find a BIG EMPTY LAND ? that cause 90% of air crash , i will suggest that using underground cables with tunnel beside them , while if the cable is damaged , use a computer to scan and ask workers to use a vehicle to travel to it . it will be much easy !
ok so first of all planes dont crash often enough to make it worth it putting powerlines below ground. powerlines dont take up that much space. underground powerlines are very lossy when using ac due to the capacitance of the ground and the resistance to ground. fixing underground lines is more dangerous because you cant lift your workers high up of the ground for saftey.
Powerlines near airports have a ball shape on the top ground wire. At night, a red light on top of the pole lights up. By the way your dumb comment was on the very bottom of the comment section.
Nice video. Explains a lot. I remember before I went to DC for the first time, my boss told me to notice how all the power lines in the city were underground
Overhead cables not being insulated or very thin insulation are kept cool by passing air, underground with thick insulations cables heat up when passing a lot of current for lengthy times thus resulting to very decreased life of the plastic insulation.
No they are rated for it
those insulations are rated for HV do some simulations on cymcap
Underground is nice but the cost and thermal ampacity limits restrict it's economical ideployment. ACSR open air conductors are far better (thermally and deployment cost) Undergrounding. Makes more sense for 12/21 KV in developed areas. Our local utility has an ongoing battle keeping 30+ year old direct burial cables operating. When we lose an aerial 12KV feeder it's less than an hour for restoration... RU feeders can be several hours to locate the fault and dig up the line...
SHORTER LIFE EXPECTANCY?!
Overhead lines change temperature faster, change temperature MORE, are exposed to wind, ozone, UV, water, ice and snow. They are exposed to MORE animals, especially squirrels and birds
Loss-costs are, on average, 2.8% for underground, vs 37% for overhead.
70% of line failures are weather-related, 11 percent are animals on overhead cables/poles/transformers...
Underground cables bring those externality risks down by at least an order of magnitude!
PhrontDoor you are wrong.
AC lines can't be buried more than 40 miles. You are talking about physics contacts to the line but the reduced life of underground lines is because the electric power pass through the ground.
Only DC voltage can pass to long distances of water/ground and have much more efficiency than AC.
profesaional！
@PhrontDoor I think you have mixed up life expectancy with risk of temporary failure. An overhead line will have a much higher risk of temporary, easily fixed failures caused by animals shorting to ground, or a tree falling on coming in contact with the line. These types of short term failures occur much more frequently on an overhead line, but they are easily resolved(most of the time), an underground line will have much lower risk of small scale failure, however the wire will age much faster due to water ingress and other conditions when compared to an overhead line, so the entire cable will have to be replaced after a shorter time.
Anywhere in the US, as I know it, don’t allow underground transmission lines. I think it’s because of the big Electromagnetic Field (EMF). Underground lines tend to be below 20 feet below the surface. When we walk near or above one of those lines, we can be severely harmed by the EMF radiation.
*Did you know?*
Transmission table
Voltage = radiation (EMF)
20-50kV = 22-77ft
50-90kV = 77-103ft
90-99kV = 103-119ft
H-shape frames
••••••Transmission level 2•••••
99kV-100kV = 119-121ft
100kV-130kV = 121-199ft
130kV-190kV = 199-213ft
190-199kV = 213-222ft
Transmission poles (200kV-210kV) and pylons (211kV+)
•••••Transmission level 3•••••
200-210kV = 229-268ft
•••••(Pylons) Transmission level 4•••••
211-240kV = 280-344ft
241kV+ equals 351ft+
EMF fields are weaker with buried lines (the electric field portion is greatly reduced) but magnetic fields remain as strong or stronger.
Aren't exposed transmission lines more harmful than the undergrounded?
Here in Florida, underground transmission lines will never happen. Floridian rate payers don't want to pay the extra cost. If anything, FPL is upgrading the wooden transmission poles to steel ones.
+fishodorvagina wouldn't that still expose the wires to weather hazards?
+OscarProGuy It will. But they won't get damaged.
fishodorvagina I see.
I live in Florida, and nearby a 200,000+ volt three phase line was buried to avoid having to cross a scenic view over a waterway near the coast. While they were at it they also buried a set of normal distribution lines as well. In Memphis Tennessee, ALL of the transmission lines and distribution lines are buried in the downtown area.
Fast forward 3 years from this post. FPL is burying all lines”hardening” on the east coast. Never say never. Lol
Life expectancy ? see what storms & fires do to your local town and just ask the insurance companies how much the damages & repairs cost vs going underground for a little added cost up front and nowadays with better materials and equipment even internal grounded expansion fittings are watertight eliminating the cost of bonding jumpers and the risk of failure and safety for longevity. Check out a company called Bams fittings and see the new technology that's available now and one of the reasons we should continue to go underground for sustainable energy vs overhead. And yes there are certain areas that need to continue with overhead this we know. But if you're gonna go underground please use new technology not old grounding technology it'll also save money and time installing it to help the bottom line in cost. Research it
passive active ultrasonic analyse of underground cable and ultrasonic frequecy triangulation wit multiple focal ultrasonic pulses
Hi ! Can I ask Permission to Download your Video as our reference in our Research in our School ? tnx
Thank you mister!
But for outside powerlines you need to build and install some "steeltowers" and it needs a lot of time to install the lines in that height. I could imagine doing a simple installion for underground lines. No underground concrete "houses" to join the lines. One machine does it all. 1. escavate 2. lower powerline 3. put concrete in 4. join with the next line 5. cover, close and finish. How can that cost more ? And why underground lines have just the half lifetime like the outside lines ? Should be inverse or not ? Undergroundlines are safe from wheater, air, water, wind and sun.
peter schiller its because the way AC current works.
The line is a conductor and also a capacitator, when you change the voltage (and you do it 60 times per second on US power grid) you need to recharge the cable 60 times a second and only after that you can have power on the other side of the cable.
With earth you have serious issues with reactance between the line and the ground. In the air this issue is 100 times less relevant.
All transmission lines between islands and mainland are with DC current because of that
building overhead lines takes less workers, goes quicker to build, materials are cheaper.
one machine and one lineman can easily build 2 km's a day overhead lines.
ALL POWERLINE MUST MAKE UNDER GROUND WITH GOOD MANPOWER.
What gauge is the wire?
I have experience 7 years jointing work 132kv 220kv 400kv Your Company any vacancy Please tell me
I read 4.5 ut micro tesla and 350 v/m volts per meter in my house from power lines over the street that I live on. Are these safe levels?
yes
Voltage is the pressure/flow of electricity pushed by a circuit the thing you have to worry about killing you is amps. Higher the voltage lower the amps higher the amps higher lower the voltage. Essentially how electricity flows over long distances
@@trevor5672 DUH, but that wasen't the question. he was more interrested in the effects of EMC
Passive utrasoun powerline supervissio and controlled interuption. 😃
“At times, burying transmission lines make sense.“
But doesn’t explain why...🤦♂️
Main reason is urbanization. Almost impossible these days to build HV OH lines in big city/metro areas. Industrial areas are another example where HV UG cable are used from HV S/S to the industrial complexes. The use of UG HV cable is only increasing with time; will be more with the increase in DER (distributed energy resources) as we have seen in Europe.
@@atlasbeast6756 When the built DFW airport, they buried the High Voltage power lines.
UG line transmission high expensive
#peace #amour #abondance #bonnheur
Overhead transmission lines running near houses causes leukemia in the people of those houses, especially kids.
Under ground transmission lines can be shielded and made safer but the power company doesn't want to afford the cost.
No, it doesn't.
yes it does.
Omega Child no it doesn't that myth was busted
Leukemia? Are you high?
i do not belong to the understanding minds, but iam just depart from that , kindly allow to express our pain
general electricty can be done underground y basic electricity supply highly a great pain to making green , unless underground electricity wire comes only then we can think of plantation and support life expectancy of human with oxygen
today oxygen tax will be the future business in india
solar and electric vechile still not in practice how for india still failing to impose
y dealer and distributor still places to make business with fuel vechil
the prices of solar vechile itself raised that is shame to indian gdp or lower end state like southern state gdp country shaming livilyhood when certain amount of oxygen itself insufficent in the earth
it take up space too . planes that need to land in emergency can't do so because of stupid tall towers in their ways , expecting them to find a BIG EMPTY LAND ? that cause 90% of air crash , i will suggest that using underground cables with tunnel beside them , while if the cable is damaged , use a computer to scan and ask workers to use a vehicle to travel to it . it will be much easy !
Can't agree more
ok so first of all planes dont crash often enough to make it worth it putting powerlines below ground. powerlines dont take up that much space. underground powerlines are very lossy when using ac due to the capacitance of the ground and the resistance to ground. fixing underground lines is more dangerous because you cant lift your workers high up of the ground for saftey.
Powerlines near airports have a ball shape on the top ground wire. At night, a red light on top of the pole lights up. By the way your dumb comment was on the very bottom of the comment section.
I'm sure in an emergency landing, watching out for power lines and telephone poles is far down on the list of things to do.
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