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206:(0.30 m) and underground lines cost in the range of $ 20 to $ 40 per 1-foot (0.30 m). In highly urbanized areas, the cost of underground transmission can be 10–14 times as expensive as overhead. However, these calculations may neglect the cost of power interruptions. The lifetime cost difference is smaller for lower-voltage distribution networks, on the range of 12-28% higher than overhead lines of equivalent voltage.
403:
areas—of burying. The disadvantages of aerial cables are that they have the same aesthetic issues as standard overhead lines and that they can be affected by storms. However, if the insulation is not destroyed during pylon failure or when hit by a tree, there is no interruption of service. Electrical hazards are minimised and re-hanging the cables may be possible without power interruption.
167:(EMF) emission, into the surrounding area. However, depending on the depth of the underground cable; greater EMF may be experienced on the surface. The electric current in the cable conductor produces a magnetic field, but the closer grouping of underground power cables reduces the resultant external magnetic field and further magnetic shielding may be provided.
378:(CPUC) Rule 20 permits the undergrounding of electrical power cables under certain situations. Rule 20A projects are paid for by all customers of the utility companies. Rule 20B projects are partially funded this way and cover the cost of an equivalent overhead system. Rule 20C projects enable property owners to fund the undergrounding.
402:
are insulated cables spun between poles and used for power transmission or telecommunication services. An advantage of aerial cables is that their insulation removes the danger of electric shock (unless the cables are damaged). Another advantage is that they forgo the costs—particularly high in rocky
223:
Whereas overhead lines can easily be uprated by modifying line clearances and power poles to carry more power, underground cables cannot be uprated and must be supplemented or replaced to increase capacity. Transmission and distribution companies generally future-proof underground lines by installing
205:
Undergrounding is more expensive, since the cost of burying cables at transmission voltages is several times greater than overhead power lines, and the life-cycle cost of an underground power cable is two to four times the cost of an overhead power line. Above-ground lines cost around $ 10 per 1-foot
219:
of underground cables produces large charging currents and so makes voltage control more difficult. Large charging currents arise due to the higher capacitance from underground power lines and thus limits how long an AC line can be. In order to avoid the capacitance issues when undergrounding long
143:
are generally considered an unattractive feature of the countryside. Underground cables can transmit power across densely populated areas or areas where land is costly or environmentally or aesthetically sensitive. Underground and underwater crossings may be a practical alternative for crossing
270:
Duct Bank - A third method uses parallel conduits held by spacers with sand or concrete filled in-between the conduits. Installation methods: conduit and spacers placed directly into a trench, conduit and spacers placed in concrete forms, or pre-made sections of concrete and
177:
Underground cables need a narrower surrounding strip of about 1–10 meters to install (up to 30 m for 400 kV cables during construction), whereas an overhead line requires a surrounding strip of about 20–200 meters wide to be kept permanently clear for safety, maintenance and
231:
in New
Zealand caused damage to 360 kilometres (220 mi) of high voltage underground cables and subsequently cut power to large parts of Christchurch city, whereas only a few kilometres of overhead lines were damaged, largely due to pole foundations being compromised by
239:
As underground repair and check up require street digging, it creates patches and potholes, leading to bumpy and unsafe ride for cars and bicycles. Utility work also increase lane closure which leads to the traffic jam and increasing cost of resurfacing work by the local
264:– This is a method in which one uses a drill bit to bore horizontal starting at one point on the surface of the ground and creating an arc underground to come back out of the surface. This method is used when minimal damage to the surface is preferred.
82:
Early undergrounding had a basis in the detonation of mining explosives and in undersea telegraph cables. Electric cables were used in Russia to detonate mining explosives in 1812, and to carry telegraph signals across the
English Channel in 1850.
361:
In
Germany, 73% of the medium voltage cables are underground and 87% of low voltage cables are underground. The high percentage of underground cables contributes to the very high grid reliability (SAIDI < 20). In comparison, the
58:
during high winds, thunderstorms or heavy snow or ice storms. An added benefit of undergrounding is the aesthetic quality of the landscape without the powerlines. Undergrounding can increase the
267:
Trench
Undergrounding - Another method for undergrounding power lines is to dig trenches, lay power lines into the trench and cover them back up. This is done for the length of the power line.
160:
Decreased risk of fire. Overhead power lines can draw high fault currents from vegetation-to-conductor, conductor-to-conductor, or conductor-to-ground contact, which result in large, hot arcs.
355:
The most visually intrusive overhead cables of the core transmission network are excluded from the scheme. Some undergrounding projects are funded by the proceeds of national lottery.
422:
560:
289:(OFGEM) permits transmission companies to recoup the cost of some undergrounding in their prices to consumers. The undergrounding must be in National Parks or designated
209:
Whereas finding and repairing overhead wire breaks can be accomplished in hours, underground repairs can take days or weeks, and for this reason redundant lines are run.
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534:
86:
With the spread of early electrical power systems, undergrounding began to increase as well. Thomas Edison used underground DC “street pipes” in his early
184:
Underground cables have a much reduced risk of damage caused by human activity such as theft, illegal connections, sabotage, and damage from accidents.
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375:
688:"Comparison between Underground Cable and Overhead Line for a Low-Voltage Direct Current Distribution Network Serving Communication Repeater"
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The advantages can in some cases outweigh the disadvantages of the higher investment cost, and more expensive maintenance and management.
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293:(AONB) to qualify. In 2021 work started on a project to bury 9 kilometres (5.6 mi) of 400kV overhead power lines running from near
290:
924:
200:
An underground cable marker. Markers are put at regular intervals to show the route and warn of the hazard of digging into the cable.
34:
A former pylon transformer south of Markgröningen, Germany. Today, the pylon carries only a switch fed by two underground cables.
390:, according to Japan's Construction and Transport Ministry, just 7.3 percent of cables were laid underground as of March 2008.
187:
Burying utility lines makes room for more large trees on sidewalks, for environmental benefits and increase of property values.
585:
212:
Underground cable locations are not always obvious, which can lead to unwary diggers damaging cables or being electrocuted.
304:
228:
686:
Kim, Kim, Cho, Song, Kweon, Chung, Choi, Jae-Han, Ju-Yong, Jin-Tae, Il-Keun, Bo-Min, Il-Yop, Joon-Ho (20 March 2014).
87:
67:
63:
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value (minutes without electricity per year) in the
Netherlands is about 30, and in the UK it is about 70.
387:
164:
713:
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All low and medium voltage electrical power (<50 kV) in the
Netherlands is now supplied underground.
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distance transmission lines, HVDC lines can be used as they do not suffer from the same issue.
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654:"Edison Electric Institute - Underground Vs. Overhead Distribution Wires: Issues to Consider"
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Residents of South City neighborhood say digging by utility is leaving bumpy patches on road
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632:
448:
333:
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940:
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Los
Angeles Department of Water & Power System Development Division cost estimate data
481:
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A compromise between undergrounding and using overhead lines is installing air cables.
216:
71:
43:
949:
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Replacement of above-ground power and telecommunications cables with underground ones
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561:"No party for thousands of Victoria residents after rogue balloons hit power lines"
535:"To curb power theft, Maharashtra explores underground supply network across state"
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Subsequent developments occurred in both insulation and fabrication techniques:
816:
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1962: Ethylene propylene rubber-insulated cables become commercially available
17:
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319:
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Most electrical power in Japan is still distributed by aerial cables. In
51:
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Underground cables pose no hazard to low-flying aircraft or to wildlife.
916:
704:
687:
447:"History of underground power cables - IEEE Journals & Magazine".
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Underground cables are more subject to damage by ground movement. The
157:, hurricanes/cyclones/typhoons, tornados, other winds, and freezing)
363:
251:
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and reduce the risk of the electrical supply being interrupted by
29:
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Less subject to damage from severe weather conditions (mainly
933:
861:
Boothroyd, John (10 December 2021). "Power for the past".
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the highest-rated cables while being still cost-effective.
758:"Underground vs. Overhead Transmission and Distribution"
586:"Truck snags power line, causes major damage downtown"
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in 1880, and progressed to rubber insulation in 1882.
423:
List of high-voltage underground and submarine cables
116:
1970s: Shrinkable cable accessories become available
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113:1963: Preformed cable accessories become available
107:1942: Polyethylene insulation first used on cables
50:, underground lines have lower risk of starting a
101:1925: Pressurized paper insulation used on cables
215:Operations are more difficult since the high
8:
718:: CS1 maint: multiple names: authors list (
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90:networks; they were insulated first with
917:City of San Diego Undergrounding Program
629:"Urban Forests | American Forests"
434:
865:. No. 182. York. pp. 49–50.
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477:
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376:California Public Utilities Commission
46:with underground cables. Compared to
496:"How Do Power Lines Cause Wildfires?"
287:Office of Gas and Electricity Markets
7:
734:"Should Power Lines be Underground?"
442:
440:
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171:Electromagnetic radiation and health
291:Areas of Outstanding Natural Beauty
104:1930: PVC insulation used on cables
340:. Similar schemes are planned for
25:
500:Texas Wildfire Mitigation Project
74:over the lifetime of the cables.
817:"Underground Transmission Lines"
922:US lobby group - Scenic America
823:from the original on 2021-12-21
781:"Roadway resurfacing in Boston"
1:
256:Cables under Broadway in 2013
132:The aerial cables that carry
229:2011 Christchurch earthquake
961:Electric power distribution
885:"Netzausbau in Deutschland"
139:and are supported by large
88:electric power distribution
64:electric power transmission
977:
521:"Underground power cables"
374:In the United States, the
934:UK lobby group - "REVOLT"
453:10.1109/MEI.2013.6545260
120:During the 20th century
617:(subscription required)
611:Letters to the editors
476:Cite journal requires
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201:
165:electromagnetic fields
40:underground power line
35:
255:
199:
33:
124:became commonplace.
48:overhead power lines
863:British Archaeology
799:, 24 September 2019
590:The Mount Airy News
418:Direct-buried cable
413:Overhead power line
316: /
122:direct-buried cable
939:2016-10-17 at the
927:2019-02-15 at the
350:North Wessex Downs
295:Winterbourne Abbas
258:
202:
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705:10.3390/en7031656
285:The UK regulator
262:Horizontal Boring
163:Reduced range of
70:but may decrease
16:(Redirected from
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44:electrical power
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896:. Retrieved
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845:. Retrieved
842:"NEC 310.60"
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764:. Retrieved
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502:. 2014-02-13
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68:distribution
60:capital cost
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898:11 November
894:(in German)
742:11 November
662:11 November
338:Dorset AONB
323: /
276:Regulations
240:government.
137:electricity
950:Categories
847:2021-11-13
827:2019-05-09
803:2022-03-19
766:2019-05-09
639:2016-01-18
506:2018-05-13
429:References
370:California
308:50°40′08″N
148:Advantages
128:Comparison
871:1357-4442
614:The State
539:DNA India
342:Snowdonia
311:2°30′50″W
155:lightning
42:provides
937:Archived
925:Archived
821:Archived
692:Energies
596:7 August
570:7 August
461:30589908
407:See also
394:Variants
348:and the
334:Weymouth
271:conduit.
144:rivers.
52:wildfire
545:20 July
248:Methods
178:repair.
78:History
56:outages
956:Cables
892:kas.de
869:
459:
344:, the
281:Europe
141:pylons
888:(PDF)
761:(PDF)
737:(PDF)
657:(PDF)
457:S2CID
382:Japan
364:SAIDI
336:) in
900:2023
867:ISSN
744:2023
720:link
664:2023
598:2020
572:2020
547:2015
482:help
169:See
92:jute
66:and
700:doi
565:CBC
449:doi
297:to
62:of
38:An
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Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
