What Actually Happens Inside a 500,000-Volt Substation?
Kilowatt Nation
24,694 views
Inside a substation, an electric arc can burn hotter than the surface of the sun. Behind a fence south of San Jose, California, there is a humming yard you would drive past without a second look. Power lines carrying 500,000 volts run into it. One night in April 2013 that yard, PG&E's Metcalf substation, came under fire. For somewhere between fifteen and twenty minutes the transformers were under fire. More than a hundred rounds. Seventeen giant transformers were knocked out, and the lights at stake were Silicon Valley's. So what actually happens inside a 500,000-volt substation?
This video walks through the gate: why the ground is covered in crushed rock; the minimum approach distance in OSHA's table for trained line workers at this voltage; how a circuit breaker puts out an arc inside a sealed chamber, and the gas called SF6 that many high-voltage breakers use; our reconstruction of an arc in open air that, by the account of the engineer who published the original footage, climbed to an estimated hundred feet during a planned test in Nevada; a transformer that can weigh more than four hundred tons and is built to order, and the wait for a new one, which averaged more than two years by 2024; why the steel core hums; the protective relays designed to cut out only the piece that failed; and three ways the grid has had a bad day anyway (a silent alarm before the 2003 blackout, squirrels, and a storm on the sun in 1989). Then it goes back to Metcalf: the 911 call, what happened to the lights in Silicon Valley, the twenty-seven days it took to bring the substation back, the question of who did it, the argument over what it meant, and the fence, sixteen months later.
CHAPTERS
00:00 Inside a 500,000-Volt Substation
00:35 The Yard Called Metcalf
01:05 April 16, 2013, Just Before 1 A.M.
01:23 Why the Ground Is Gravel
01:49 Electricity Can Arc Across an Air Gap
02:08 What a Circuit Breaker Really Does
02:55 The Gas Called SF6
03:13 An Arc in the Open Air
04:22 How Hot Is an Electric Arc?
04:57 More Than a Hundred Rounds
05:27 A Machine That Can Top 400 Tons
06:14 The Wait for a New Transformer
07:02 Why a Substation Hums
07:26 52,000 Gallons of Oil
07:48 The Yard Sounds the Alarm
08:08 Reflexes of Its Own
09:14 2003: The Alarm That Went Quiet
10:28 Squirrels and Nasdaq
11:33 1989: A Storm on the Sun
12:26 How the Night Ended
13:01 Taking Stock
14:08 Who Did It?
15:11 The Argument Over What It Meant
15:55 What Changed Afterward
16:19 The Fence, Sixteen Months Later
16:44 Not the Last Yard
17:36 The Yard You Drive Past
WATCH NEXT
What Actually Moves Through a 500,000-Volt Power Line?: What Actually Moves Through a 500,000-Volt...
Why Does America Still Run on 60 Hz and 120 Volts?: Why Is America 60 Hz When Europe Is 50 Hz?
Before the Third Hole, What Kept You From Being Electrocuted?: Before the Third Hole, What Kept You From ...
SOURCES
California Public Utilities Commission, "PG&E Metcalf Incident and Substation Security" (2014) and Citation 15-08-001 (2015); Congressional Research Service, R43604 (2015)
NPR and Voice of America (February 2014), on The Wall Street Journal's account; CBS San Francisco; CNN Money; KRON4; ABC7; Fox News; Utility Dive; Marketplace (April 14, 2023)
OSHA, "Electric-Arc Flash Hazards" and 29 CFR 1926.960, 1910.269 Appendix C and 1910.399; NASA, "Sun: Facts"; NIST Technical Note 1425; EPA, "Sulfur Hexafluoride (SF6) Basics"; Schweitzer Engineering Laboratories (2015); Bonneville Power Administration; Commonwealth Associates; Bert Hickman, capturedlightning.com
U.S. Department of Energy, "Large Power Transformers and the U.S. Electric Grid" (April 2014); National Infrastructure Advisory Council, draft report (June 2024); Department of Homeland Security (2015); E&E News; Renewable Energy World; Rex Power Magnetics
U.S.-Canada Power System Outage Task Force, Final Report on the August 14, 2003 Blackout (April 2004); The Register (April 8, 2004)
American Public Power Association (2017, 2024); Nebraska Public Media (2025); NPR (July 8, 2015), citing The New York Times; UPI (December 9, 1987); GAO/AIMD-95-22
Hydro-Quebec; U.S. Nuclear Regulatory Commission, Information Notice 90-42; Space Weather Canada
Department of Energy Inspector General, DOE/IG-0933 (January 2015); FERC Order No. 802 (Federal Register, November 25, 2014); NPR (March 14, 2014); Courthouse News; NBC News; The Sanford Herald; U.S. Attorney's Office, Western District of Washington; Bloomberg
Aerial imagery: USDA NAIP. Map services and data available from U.S. Geological Survey, National Geospatial Program. Night-lights images: courtesy Chris Elvidge, U.S. Air Force, via NASA Earth Observatory. Solar imagery: NASA/Goddard Space Flight Center Scientific Visualization Studio; courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.
Kilowatt Nation tells the story of the American power grid through the people who built it, the money and deals that shaped it, and the nights it failed.
#Substation #PowerGrid #Transformer #Metcalf #KilowattNation
13 Comments
It's an annoying trend that all information videos are copying
What Actually Happens Inside a 500,000-Volt Substation?
Kilowatt Nation
24,694 views
Inside a substation, an electric arc can burn hotter than the surface of the sun. Behind a fence south of San Jose, California, there is a humming yard you would drive past without a second look. Power lines carrying 500,000 volts run into it. One night in April 2013 that yard, PG&E's Metcalf substation, came under fire. For somewhere between fifteen and twenty minutes the transformers were under fire. More than a hundred rounds. Seventeen giant transformers were knocked out, and the lights at stake were Silicon Valley's. So what actually happens inside a 500,000-volt substation?
This video walks through the gate: why the ground is covered in crushed rock; the minimum approach distance in OSHA's table for trained line workers at this voltage; how a circuit breaker puts out an arc inside a sealed chamber, and the gas called SF6 that many high-voltage breakers use; our reconstruction of an arc in open air that, by the account of the engineer who published the original footage, climbed to an estimated hundred feet during a planned test in Nevada; a transformer that can weigh more than four hundred tons and is built to order, and the wait for a new one, which averaged more than two years by 2024; why the steel core hums; the protective relays designed to cut out only the piece that failed; and three ways the grid has had a bad day anyway (a silent alarm before the 2003 blackout, squirrels, and a storm on the sun in 1989). Then it goes back to Metcalf: the 911 call, what happened to the lights in Silicon Valley, the twenty-seven days it took to bring the substation back, the question of who did it, the argument over what it meant, and the fence, sixteen months later.
CHAPTERS
00:00 Inside a 500,000-Volt Substation
00:35 The Yard Called Metcalf
01:05 April 16, 2013, Just Before 1 A.M.
01:23 Why the Ground Is Gravel
01:49 Electricity Can Arc Across an Air Gap
02:08 What a Circuit Breaker Really Does
02:55 The Gas Called SF6
03:13 An Arc in the Open Air
04:22 How Hot Is an Electric Arc?
04:57 More Than a Hundred Rounds
05:27 A Machine That Can Top 400 Tons
06:14 The Wait for a New Transformer
07:02 Why a Substation Hums
07:26 52,000 Gallons of Oil
07:48 The Yard Sounds the Alarm
08:08 Reflexes of Its Own
09:14 2003: The Alarm That Went Quiet
10:28 Squirrels and Nasdaq
11:33 1989: A Storm on the Sun
12:26 How the Night Ended
13:01 Taking Stock
14:08 Who Did It?
15:11 The Argument Over What It Meant
15:55 What Changed Afterward
16:19 The Fence, Sixteen Months Later
16:44 Not the Last Yard
17:36 The Yard You Drive Past
WATCH NEXT
What Actually Moves Through a 500,000-Volt Power Line?: What Actually Moves Through a 500,000-Volt...
Why Does America Still Run on 60 Hz and 120 Volts?: Why Is America 60 Hz When Europe Is 50 Hz?
Before the Third Hole, What Kept You From Being Electrocuted?: Before the Third Hole, What Kept You From ...
SOURCES
California Public Utilities Commission, "PG&E Metcalf Incident and Substation Security" (2014) and Citation 15-08-001 (2015); Congressional Research Service, R43604 (2015)
NPR and Voice of America (February 2014), on The Wall Street Journal's account; CBS San Francisco; CNN Money; KRON4; ABC7; Fox News; Utility Dive; Marketplace (April 14, 2023)
OSHA, "Electric-Arc Flash Hazards" and 29 CFR 1926.960, 1910.269 Appendix C and 1910.399; NASA, "Sun: Facts"; NIST Technical Note 1425; EPA, "Sulfur Hexafluoride (SF6) Basics"; Schweitzer Engineering Laboratories (2015); Bonneville Power Administration; Commonwealth Associates; Bert Hickman, capturedlightning.com
U.S. Department of Energy, "Large Power Transformers and the U.S. Electric Grid" (April 2014); National Infrastructure Advisory Council, draft report (June 2024); Department of Homeland Security (2015); E&E News; Renewable Energy World; Rex Power Magnetics
U.S.-Canada Power System Outage Task Force, Final Report on the August 14, 2003 Blackout (April 2004); The Register (April 8, 2004)
American Public Power Association (2017, 2024); Nebraska Public Media (2025); NPR (July 8, 2015), citing The New York Times; UPI (December 9, 1987); GAO/AIMD-95-22
Hydro-Quebec; U.S. Nuclear Regulatory Commission, Information Notice 90-42; Space Weather Canada
Department of Energy Inspector General, DOE/IG-0933 (January 2015); FERC Order No. 802 (Federal Register, November 25, 2014); NPR (March 14, 2014); Courthouse News; NBC News; The Sanford Herald; U.S. Attorney's Office, Western District of Washington; Bloomberg
Aerial imagery: USDA NAIP. Map services and data available from U.S. Geological Survey, National Geospatial Program. Night-lights images: courtesy Chris Elvidge, U.S. Air Force, via NASA Earth Observatory. Solar imagery: NASA/Goddard Space Flight Center Scientific Visualization Studio; courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.
Kilowatt Nation tells the story of the American power grid through the people who built it, the money and deals that shaped it, and the nights it failed.
#Substation #PowerGrid #Transformer #Metcalf #KilowattNation
I once was responsible for the design and construction of a 10 MW transformer and it took 18 months to complete