GCRI · Energy Nexus
Grid disruption and recovery
Large outages come from storms, wildfires, heat, ice, floods, earthquakes, geomagnetic storms, equipment failure, operator error and cyberattack. How long they last depends less on the cause than on how quickly the grid can be restarted and repaired. This page sets out how outages unfold, how black start and restoration work, how critical services are prioritised, and what evidence operators, regulators and civil protection authorities use.
Grid disruption and recovery in seven parts.
- 01The questionGrid disruption and recovery: how the risk develops
- 02CouplingsWhat stops when the lights go out, in order
- 03Reports, standards and contributionsRestoration evidence and how it is shared
- 04IndicatorsWhat is measured, and how well
- 05SourcesWhere the evidence comes from
- 06DecisionsWho decides, and what the evidence serves
- 07Core questionsWhat restoration experts ask
Grid disruption and recovery: how the risk develops.
Outages, black-start and critical service restoration. The dossier below sets out how the risk develops, what is measured, where the data come from, how it is modelled and who decides.
From damage to outage
Wind, ice and falling trees bring down distribution lines; floods inundate substations; wildfire risk forces preventive de-energisation. Distribution damage usually causes most customer outage minutes, while transmission failures cause the widest outages.
Black start
After a system-wide collapse, operators restart from units that can start without external power, such as hydropower, some gas turbines or batteries, then energise transmission paths and pick up load in steps while holding frequency stable.
Critical services fall back
Hospitals, water works, telecommunications and fuel stations depend on backup generators with limited fuel. Mobile networks fail as site batteries run down, which slows the very restoration that depends on communications.
Recovery bottlenecks
Restoration is limited by crews, spare transformers, road access, fuel logistics and communications. Large power transformers take a long time to manufacture and move, so spares and mutual-aid agreements largely decide recovery time.
Energy now in Europe.
Night lights, population density and flood water over Europe, from NASA GIBS. Each layer carries its own date.
The interactive map needs JavaScript; the layer list and sources are below.
Layers 3
Energy now, for this page
About this layer
- Evidence
- Observed
- Source
- VIIRS Black Marble (VNP46A2) (NASA LAADS DAAC)
- Provider
- NASA LAADS DAAC
- Licence
- NASA open data
- Vintage
- daily; Satellite radiance, corrected for moonlight and atmosphere
- Newest at build
- 2026-10-12
- Resolution
- about 500 m grid
- Uncertainty
- Satellite night-time radiance for the date shown; lights are a proxy for electricity use and outages, not a measurement of supply or access.
- Reached through
- gibs.earthdata.nasa.gov, only after you allow the live map
About this layer
- Evidence
- Estimated
- Source
- Gridded Population of the World v4.11 (NASA SEDAC (CIESIN, Columbia University))
- Provider
- NASA SEDAC (CIESIN, Columbia University)
- Licence
- CC BY 4.0
- Vintage
- null; Census-based estimate, static (2020)
- Resolution
- about 1 km grid
- Uncertainty
- Census-based estimate of people per square kilometre in 2020, shown as exposure context; not a count of people affected by any hazard.
- Reached through
- gibs.earthdata.nasa.gov, only after you allow the live map
About this layer
- Evidence
- Observed (clouds leave gaps)
- Source
- VIIRS Global Flood Product (NASA LANCE)
- Provider
- NASA LANCE
- Licence
- NASA open data
- Vintage
- daily; Satellite detection; clouds leave gaps
- Newest at build
- 2026-10-14
- Resolution
- about 250 m grid
- Uncertainty
- Satellite detection; clouds leave gaps. Satellite or model raster as the provider publishes it. Clouds, swath gaps and retrieval error leave gaps and noise; values are indicators, not measurements at a place.
- Reached through
- gibs.earthdata.nasa.gov, only after you allow the live map
About this layer
- Evidence
- Observed
- Source
- VIIRS NOAA-20 corrected reflectance (NASA LANCE)
- Provider
- NASA LANCE
- Licence
- NASA open data
- Vintage
- daily; Satellite image
- Newest at build
- 2026-10-14
- Resolution
- about 250 m grid
- Uncertainty
- Satellite image. Satellite or model raster as the provider publishes it. Clouds, swath gaps and retrieval error leave gaps and noise; values are indicators, not measurements at a place.
- Reached through
- gibs.earthdata.nasa.gov, only after you allow the live map
About this layer
- Evidence
- Modelled (latest year GIBS publishes)
- Source
- MODIS Terra and Aqua land cover (MCD12Q1) (NASA LP DAAC)
- Provider
- NASA LP DAAC
- Licence
- NASA open data
- Vintage
- yearly; Satellite classification; latest year GIBS publishes
- Newest at build
- 2024-01-01
- Resolution
- about 500 m grid
- Uncertainty
- Satellite land cover classes for the year shown, including croplands; a classification with known errors, not a farm register.
- Reached through
- gibs.earthdata.nasa.gov, only after you allow the live map
About this layer
- Evidence
- Observed (clouds and overpass timing leave gaps)
- Source
- VIIRS NOAA-20 375 m (FIRMS) (NASA LANCE FIRMS)
- Provider
- NASA LANCE FIRMS
- Licence
- NASA open data
- Vintage
- daily; Satellite detection; clouds and overpass timing leave gaps
- Newest at build
- 2026-10-13
- Resolution
- about 500 m grid
- Uncertainty
- Satellite hot-spot detections for the day shown, including gas flares and industrial heat; not a confirmed fire, an incident report or a warning.
- Reached through
- gibs.earthdata.nasa.gov, only after you allow the live map
Keyboard, with the map focused
Hold Ctrl or ⌘ and scroll to zoom
Latest available
NASA GIBS / EOSDIS · ASTER GDEM (METI, NASA) · Blue Marble (NASA) · © OpenStreetMap contributors (ODbL) · Natural Earth
Loading the latest NASA imagery.
Drag to move. Ctrl or ⌘ and scroll, pinch or the buttons to zoom; hover for the values under the pointer; reset returns to the region.
Energy now, framed on Europe.Satellite and model products as NASA publishes them, each with its own date. They are indicators, not assessments of any place.
Data: NASA GIBS · ASTER GDEM · Blue Marble · © OpenStreetMap contributors · Natural Earth · NASA EONET · NASA/NOAA VIIRS · NASA JPL OPERA DIST-ALERTSources and licences
- We acknowledge the use of imagery provided by services from NASA’s Global Imagery Browse Services (GIBS), part of NASA’s Earth Science Data and Information System (ESDIS). Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). NASA open data
- We acknowledge the use of imagery provided by services from NASA’s Global Imagery Browse Services (GIBS), part of NASA’s Earth Science Data and Information System (ESDIS). Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). NASA open data
- VIIRS Black Marble night-time lights, NASA Goddard Space Flight Center; distributed by the NASA Level-1 and Atmosphere Archive and Distribution System (LAADS DAAC); imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). NASA open data
- Center for International Earth Science Information Network (CIESIN), Columbia University. 2018. Gridded Population of the World, Version 4 (GPWv4): Population Density, Revision 11. NASA Socioeconomic Data and Applications Center (SEDAC). Licensed under CC BY 4.0. Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). doi:10.7927/H49C6VHW. CC BY 4.0
- VIIRS near-real-time products (flood, land surface temperature, snow cover, corrected reflectance), NASA LANCE; imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). NASA open data
- MODIS land products (vegetation indices, gross primary production, land cover), NASA LP DAAC and LANCE; imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). NASA open data
- NASA Fire Information for Resource Management System (FIRMS), VIIRS 375 m active fire product, NASA LANCE; vector tiles via NASA GIBS. Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). NASA open data
- ASTER GDEM is a product of METI and NASA (ASTER Global Digital Elevation Model V003, NASA LP DAAC); imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). Cite as: NASA/METI/AIST/Japan Spacesystems and U.S./Japan ASTER Science Team (2019). ASTER Global Digital Elevation Model V003. doi:10.5067/ASTER/ASTGTM.003. NASA open data
- Made with Natural Earth. Free vector and raster map data @ naturalearthdata.com. Public domain
- © OpenStreetMap contributors (ODbL), via NASA GIBS (coastlines, boundaries, roads and place names). Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). ODbL
- Blue Marble, NASA Earth Observatory; imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). NASA open data
- Context on the globe and flat map: coastlines, boundaries, roads and place names from NASA GIBS reference layers (OpenStreetMap data, ODbL, © OpenStreetMap contributors); Blue Marble imagery as an optional base; 3D terrain and the elevation read-out from the ASTER GDEM elevation colour index (5 m to 200 m classes, exaggerated for legibility). Boundaries are drawn as published and imply no position on any territory.
- Live events: NASA Earth Observatory Natural Event Tracker (EONET); events are indicative and keep their original source links.
- Observed (EO): NASA/NOAA VIIRS (Suomi NPP). We acknowledge the use of imagery provided by services from NASA’s Global Imagery Browse Services (GIBS), part of NASA’s Earth Science Data and Information System (ESDIS).
- Observed (EO): NASA JPL OPERA DIST-ALERT (contains modified Copernicus Sentinel data 2026). We acknowledge the use of imagery provided by services from NASA’s Global Imagery Browse Services (GIBS), part of NASA’s Earth Science Data and Information System (ESDIS).
- NASA GIBS: We acknowledge the use of imagery provided by services from NASA’s Global Imagery Browse Services (GIBS), part of NASA’s Earth Science Data and Information System (ESDIS).
- Past year, daily temperature (ERA5 via Open-Meteo): Contains modified Copernicus Climate Change Service information 2026.
- Past year, daily temperature and sunshine (NASA POWER): These data were obtained from the NASA Langley Research Center (LaRC) POWER Project funded through the NASA Earth Science/Applied Science Program..
- Weather data by Open-Meteo.com (https://open-meteo.com/), licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/).
- Optional layers (10 sources in the layer list: live, forecast, observed and context) print their provider credit on the map and here when switched on; forecasts are model output and derived indices are estimates.
Layers and dates
- Night-time lights, daily: VIIRS Black Marble (VNP46A2), NASA LAADS DAAC · 12 Oct 2026
- Population density, 2020: Population: CIESIN, Columbia University, Gridded Population of the World v4.11 (2018), NASA SEDAC, CC BY 4.0 · static
- Flood water, 3-day composite: VIIRS Global Flood Product, NASA LANCE · 14 Oct 2026
- True colour: VIIRS NOAA-20 corrected reflectance, NASA LANCE · 13 Oct 2026
- Land cover type (IGBP), yearly: MODIS Terra and Aqua land cover (MCD12Q1), NASA LP DAAC · 2024
- Active fires and thermal anomalies: VIIRS NOAA-20 375 m (FIRMS), NASA LANCE FIRMS · 13 Oct 2026
What stops when the lights go out, in order.
| Domain | How it couples here | What to watch |
|---|---|---|
| Water | Pumping and treatment stop within hours unless backup holds; pressure loss raises contamination risk. See drinking water and sanitation. | Hours of backup at critical water sites |
| Health | Hospitals switch to generators; dialysis, oxygen and cold chains are at risk. See health system continuity. | Generator fuel autonomy at hospitals |
| Food | Cold chains, retail and payment systems fail together. | Food retail continuity during outages |
| Biodiversity | Wildfire-related shutoffs and storm damage link outages to landscape conditions. | Vegetation-related outage causes |
Outage impact is reported as SAIDI and SAIFI (IEEE 1366) and as energy not supplied in megawatt-hours. The joint FERC and NERC staff report on the February 2021 cold-weather outages in Texas and the south-central United States documented how gas supply, generation and demand failed together under cold, a pattern now studied for heat and drought.
Grid contingency board.
The screen a team would use to follow this subject: its measures, states and decisions. Names are examples and values are illustrative.
Restoration evidence and how it is shared.
Restoration and cascade studies are designed for the Scenario and Stress-Test series and exercises for the Universe Annual Synthesis. Exercise records would carry NS-11 verification evidence under the proposed Nexus Standards.
- Restoration timelines for power and dependent services after real events.
- After-action reviews from operators and civil protection.
- Records of which critical customers had backup and how long it lasted.
A cascade through interdependent networks.
A hazard footprint takes out co-located assets in every layer; fragmentation, dependency between layers and overload of the survivors then spread the failure. The 3D view separates the layers by depth. Teaching model with stated illustrative values, not a prediction. The map on this page shows Europe; the model itself is not tied to a place.
Controls
- Assets per layer
- 18
- Hazard footprint
- 8% of area
- Assets that depend on another layer
- 60%
- Spare capacity (tolerance)
- 30%
Readouts
- Assets hit by the hazard
- 9%
- Assets still working
- 33%
- Amplification of the initial damage
- 7.2 times
- Steps to settle
- 4
Numbers, methods and sources
| Step | Power working (%) | Gas working (%) | Telecoms working (%) |
|---|---|---|---|
| 0 | 89 | 94 | 89 |
| 1 | 61 | 78 | 56 |
| 2 | 44 | 39 | 44 |
| 3 | 33 | 28 | 44 |
| 4 | 33 | 28 | 39 |
Methods
- Interdependent networks Buldyrev and others (2010), Catastrophic cascade of failures in interdependent networks, Nature 464
- Overload cascades Motter and Lai (2002), Physical Review E 66
- Betweenness load Brandes (2001), Journal of Mathematical Sociology 25
- Multilayer networks Kivela and others (2014), Journal of Complex Networks 2
- Infrastructure interdependencies Rinaldi, Peerenboom and Kelly (2001), IEEE Control Systems 21(6)
- Uncertainty fan (parameter Monte Carlo) Spiegelhalter, Pearson and Short (2011), Visualising uncertainty about the future, Science 333
- One-at-a-time sensitivity (tornado) Saltelli and others (2008), Global Sensitivity Analysis: The Primer, Wiley
Data
The model runs on the teaching values set by the controls. To calibrate it for a place, read it against these admitted layers and series, which this page’s map can draw:
- Major roads Natural Earth
- Railways Natural Earth
- Seaports Natural Earth
- Airports Natural Earth
- Urban extents Natural Earth
- Night lights tonight, outages (VIIRS Day/Night Band) NASA/NOAA VIIRS (Suomi NPP) · register nasa.gibs.context-live-layers
- Natural events (NASA EONET) NASA EONET · register nasa.eonet.events
Across the six pillars, led by Nexus Consortium
- Experiments Labs
- Built in Energy Nexus in Foundry
- Tested at Energy Nexus in Universe
- Codified in Energy and Critical Infrastructure in Standards
- Published in Energy Nexus in Reports
- Taught in Faculty of Infrastructure, Energy and Industry in Academy
What is measured, and how well.
Each indicator carries its unit, its cadence, the kind of source behind it and the evidence label a value would carry. No values are shown: a programme supplies them under its own authority.
| Indicator | Unit | Cadence | Source type | Label |
|---|---|---|---|---|
| Customer minutes lost | customer minutes | per event | Utility outage management systems | Published statistics |
| Customers without power over time | customers | hourly during events | Utility outage reporting | REPORTED |
| Restoration curve | percent of customers restored against elapsed hours | per event | Utility and regulator event reports | REPORTED |
| Loss of night-time lights in the affected area | change in radiance | daily | Satellite night-time lights | OBSERVED |
| Backup power endurance at critical sites | hours | per asset | Facility and asset registers | Published statistics |
| Contracted black start capability | megawatts | annual | Operator restoration plans | DECLARED |
| Mobile network site availability | percent of sites operating | hourly during events | Telecommunications regulator status reports | REPORTED |
Model grid disruption and recovery as a system. Run the cascade.
Assembled from the Nexus Standards area profile Energy utilities and grids: the hazards it names, the systems and sectors that carry the loss, the controls that dampen it and the data that observe it. Choose the components, pick an initiating hazard and step through the cascade. The Map view places the run on an example geography with open data. Every coupling weight is a stated assumption you can change. A teaching model, not a forecast, an assessment or a certification. To model a place of your own choosing, open the full System Builder.
Hazards
- Windstorm
- Geomagnetic storm
- Widespread power outage (set off downstream)
- Large forest disturbance (set off downstream)
- Wildfire (set off downstream)
- Geomagnetically induced current (set off downstream)
- Ionospheric disturbance (set off downstream)
- Satellite space-environment anomaly (set off downstream)
- Shoreline ice shove (set off downstream)
- Thermospheric drag surge (set off downstream)
- Radiation-belt electron enhancement (set off downstream)
- Seiche (set off downstream)
- Satellite-navigation disruption (set off downstream)
- Uncontrolled re-entry (set off downstream)
- Satellite communications outage (set off downstream)
Systems and couplings
Controls
NS-0Constitution and principlesNS-3Risk record UNIs (grammar, legacy crosswalk, allocation authority)NS-9Contextual UNIs (deployments, instances, programme instances)NS-10Policies and clauses (machine-readable obligations: definition, binding, evaluation and enforcement)NS-11Verification and monitoring (evidence, attestations, zero-trust conformance observation)NRS-H84Hazard family: Energy system instability and shortfall (NHS-1 infra.energy)NRS-N2Energy risk and resilienceNRS-H109Hazard family: Energy-transition technology failures (NHS-1 tech.energy-transition)NRS-U8Universe platform profile: Energy NexusNRS-T12Energy transition technology riskNRS-H53Hazard family: Cyber-physical disruption (NHS-1 cyber.cyber-physical)
Observation
- Global Power Plant Database v1.3.0 (listed for reference)
- ENTSO-E Transparency Platform (listed for reference)
- World Development Indicators (listed for reference)
- OECD Data Explorer (incl. Creditor Reporting System, insurance and pension statistics) (listed for reference)
- Proportion of population with access to electricity
- Renewable energy share in the total final energy consumption
- Number of other destroyed or damaged critical infrastructure units and facilities, attributed to disasters
- Access to electricity (% of population)
- Electric power transmission and distribution losses (% of output)
Example geography
- Europe: 113 hexagonal cells
- Rain rate, last half hour (IMERG), NASA GIBS
- Night lights tonight, outages (VIIRS Day/Night Band), NASA GIBS
- Vegetation disturbance alerts, 30 m (OPERA DIST-ALERT), NASA GIBS
- Carbon monoxide, smoke transport (AIRS), NASA GIBS
Where the evidence comes from.
Named public datasets and institutional records, each with its licence class. Sources by agreement are used only under their terms and never republished.
| Source | What it gives | Licence class |
|---|---|---|
| DOE Form OE-417 electric emergency incident and disturbance reports | Major outages and disturbances in the United States | Public domain |
| NASA Black Marble night-time lights (VIIRS) | Daily night-time radiance for mapping outage and recovery | Public domain |
| NERC event analyses and FERC inquiry reports | Reconstructions of major disturbances and recommendations | Public reports |
| ENTSO-E incident classification scale reports and expert panel reports | Classification and investigation of European grid incidents | Public reports, ENTSO-E terms |
| EM-DAT international disaster database (CRED) | Disaster events with their reported infrastructure impacts | Free for non-commercial use, registration |
| FCC Disaster Information Reporting System status reports | Communications outages during activated disasters in the United States | Public domain |
| Utility and regulator outage records | Event timelines, customers affected and restoration progress | Public records or by agreement |
How grid disruption and recovery is modelled, measured and tested.
The model, its assumptions, its data and its uncertainty, in the form a scientist or engineer would check. Structures follow published methods. The values drawn are illustrative, not findings.
System model
The couplings between the systems in grid disruption and recovery: signs of influence, a reinforcing and a balancing loop, and cross-links where stress jumps.
Who decides, and what the evidence serves.
Energy Nexus prepares evidence. The decisions below are taken by the authorities named, under their own rules, and never by the platform.
| Who decides | The question | Evidence this page serves |
|---|---|---|
| Transmission and distribution operators | How to sequence restoration and which loads to restore first | Restoration plans, dependency maps, backup endurance at critical sites |
| Energy regulators | Whether resilience investment such as undergrounding, hardening or spares is justified | Customer minutes lost by cause, restoration curves, cost and benefit evidence |
| Civil protection and emergency management agencies | Where to send generators, fuel and shelter capacity during a long outage | Outage extent from night-time lights and utility data; critical service maps |
| Hospital, water and telecommunications operators | How much backup power and fuel to hold and how to secure resupply | Endurance records, past outage durations, fuel logistics evidence |
Outputs this topic produces
- Restoration curves reconstructed from public records of past events
- Critical service dependency maps with backup endurance
- Disruption scenarios for storms, heat, wildfire and geomagnetic events
- Briefs on spare equipment, mutual aid and black start arrangements
What restoration experts ask.
- Which plants can start without external power, and are there enough of them, in the right places?
- How long can telecommunications, water and hospitals keep running on backup power and fuel?
- In what order should load be restored to keep the system stable and protect people at greatest risk?
- How do distributed resources such as rooftop solar complicate or help restoration?
Why recovery is harder than it looks.
Restoration typically builds islands of supply around black-start plants, then synchronises them with each other and with neighbouring systems. Each step must keep frequency and voltage within limits while operators work with partial information.
Starting from nothing
Only some plants can start without grid power. Others need power to run pumps and controls before they can generate.
Restoration needs other services
Crews need telecommunications and fuel, which themselves need power. Backup batteries and generators run down.
Careful rebuilding
Reconnecting load too fast can collapse the partially rebuilt system and restart the process.
How recovery is studied and prepared.
- 01
Restoration planning
Operators maintain restoration plans and test parts of them. Full-system tests are rarely possible.
- 02
Dependency mapping
Network science and resilience engineering map which services need which supply and how long backup lasts. Backup data is often incomplete.
- 03
Exercises
Cross-sector exercises test assumptions between energy, water, telecommunications and emergency services.
- 04
Event reviews
Post-event reports remain the main evidence. Their findings are not always comparable across countries.
How it is studied, and what the methods cannot say.
- 01Reliability and resilience engineeringRestoration curve analysis · Fault trees for critical sites · Fragility curves for grid assetsApplied here
- 02Power systems engineeringContingency and load flow studies · Frequency stability with less inertiaApplied here
- 03Network science and contagionInterdependency mapping · Cascades on multilayer networks · Criticality rankingApplied here
- 04Optimisation and operations researchCapacity expansion planning · Unit commitment and dispatch · Restoration sequencingApplied here
- 05Forecasting and time-series analysisLoad forecasting with weather · Wind and solar power forecasts · Seasonal adequacy outlooksApplied here
Where this page’s references lead.
The bodies and documents this page is read against. Status and editions change; each link goes to the issuing body.
- IEEE Standard 1366, Guide for Electric Power Distribution Reliability Indices (IEEE)
- February 2021 Cold Weather Outages in Texas and the South Central United States (FERC, NERC and Regional Entity staff report, 2021)
- ENTSO-E, including the expert panel investigation of the 28 April 2025 Iberian Peninsula blackout
- NS-11, Verification and monitoring, a proposed standard
Where this page leads across the Consortium.
Questions and answers.
What is black start?
Why do some outages last much longer than others?
Can satellites see outages?
Why can’t the grid simply be switched back on?
Who gets power back first?
Does Energy Nexus run outage exercises?
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