What to do when the power goes out

The Cabinet Office says outages can happen anywhere in Japan, all year round, from quakes, floods, heavy snow and accidents, yet only about 43% of households had a foot light or torch ready for a night-time quake blackout (2017 survey).

最初にやることFirst 5 minutes

TEPCO’s first advice: stay calm and check what is happening around you (急に電気が消えたときは、まずは落ち着いて近隣の状況を確認してください). Then:

Official English · TEPCO Power Grid 東京電力パワーグリッド

• “Unplug any electrical appliances or devices that generate heat such as irons, hair driers, and sheath heaters from the outlet in order to prevent fire when the power is restored.”

— What to do if the power goes out, 4. Precautions for Power Outages: https://www.tepco.co.jp/en/pg/outage/todo-e.html · checked 1 Nov 2026

The Fire and Disaster Management Agency (FDMA) adds: during an outage, switch off and unplug electrical and heating appliances, and if you leave home, turn off the breaker. More on why in the fire section.

ブレーカーJust your home, or the whole area?

If the neighbours and street are dark too, it is an area outage: skip to outage info. If only your home or one room is dark, check the breaker box (分電盤 bundenban). TEPCO explains it in English:

Official English · TEPCO Power Grid 東京電力パワーグリッド

Whole home dark: “The ampere breaker can be tripped if the use of many electrical appliances at the same time results in the contract ampere capacity being exceeded. Reduce the amount of appliances or devices being used and then turn the ampere breaker switch upward.” (“No ampere breaker is installed if your contract ampere capacity is set by smart meter.”)

If the earth leakage breaker has tripped: “Turn off all switches of the distribution line circuit breakers. After turning on the switch of the earth leakage circuit breaker, turn on the switches of the distribution line circuit breakers one at a time.” If one circuit trips it again, it may have a leak: leave that one off and turn the others back on.

One room dark: “Unplug the appliance or device from the socket, turn on the switch of the distribution line circuit breaker…”

— What to do if the power goes out, sections 2–3: https://www.tepco.co.jp/en/pg/outage/todo-e.html · checked 1 Nov 2026

Translated · TEPCO Power Grid 東京電力パワーグリッド

Before you touch the breakers: if you feel at all unsure, or the breaker smells burnt, makes a strange noise, or part of it has melted, don’t operate it: contact TEPCO Power Grid straight away. Take care not to fall in the dark or off a step stool.

原文 (Japanese original)

夜間や踏み台を使用する場合は、つまづきや転倒に十分気を付けてください。少しでも不安を感じたり、以下のような場合は操作を行わず、すみやかに東京電力パワーグリッドまでご連絡ください。・ブレーカーから焦げくさい臭いがする ・ブレーカーから変な音がする ・ブレーカーの一部が溶けている ・アンペアブレーカーの取り付け有無が分からない

— 東京電力パワーグリッド「急に電気が消えたとき」: https://www.tepco.co.jp/pg/consignment/for-general/trouble.html · checked 1 Nov 2026

TEPCO says to have a leaking circuit checked by an electrical contractor (電気工事店). WardReady suggestion: if you rent, tell your management company (管理会社) too.

停電情報Checking outage info (停電情報)

In Tokyo (TEPCO Power Grid area), the live outage map is teideninfo.tepco.co.jp (Japanese). Pick your prefecture on the map, then your city. TEPCO notes:

• Right after an outage starts it may not be listed yet; the page updates about every 10 minutes.
• Damage to the line into your building, or inside it, may never show up. Dark but not listed? Contact TEPCO Power Grid.
• Web chat and LINE chat run 24 hours (Japanese).

Official English · TEPCO Power Grid 東京電力パワーグリッド

Outages, utility poles and wires: 0120-995-007 (toll-free), or 03-6375-9803 (paid) if you can’t use 0120 numbers. “Calls regarding emergencies such as power outages can be received 24 hours a day, every day.” When reporting, give “your address, name, phone number, and a readily recognized nearby landmark.”

“Information regarding power outage recovery progress and similar items might be provided by taped message due to the temporary heavy concentration of phone calls.”

— Contact Information; Power Outage?: https://www.tepco.co.jp/en/pg/outage/contact-e.html · checked 1 Nov 2026

Contract questions go to your retail electricity company (小売電気事業者), but outages go to TEPCO Power Grid, which runs the lines. Other regions have their own grid company and outage page (Japanese):

Phones and internet may go down in a big blackout. The Cabinet Office leaflet says to keep a radio and spare batteries for news.

通電火災The big one: fire when power comes back

When power returns after a quake or flood, damaged wiring or a toppled heater can start a fire, perhaps while you are away at a shelter. This is 通電火災 (tsūden kasai).

Translated · FDMA 消防庁

“A tsūden kasai is a fire caused when, after power is restored, a heater or other combustion appliance knocked over by the shaking touches nearby flammable things (such as a rug), or when electrical appliances or wiring damaged by the shaking short-circuit as the power returns.” The same happens after recent floods, from appliances damaged by water.

原文 (Japanese original)

通電火災とは、地震の揺れにより転倒した暖房機器等の燃焼機器が再通電後に周辺の可燃物（絨毯など）に接触すること、揺れにより損傷した電気機器・配線が再通電時にショートすること等により発生する火災のことを指す。なお、地震のみならず、最近の風水害においても浸水で損傷した電気機器等から同様の要因により通電火災が発生しており注意が必要である。

— 消防庁「令和5年版 消防白書」地震火災への備え: https://www.fdma.go.jp/publication/hakusho/r5/report7/68438.html · checked 1 Nov 2026

The Cabinet Office says that in the 2011 Great East Japan Earthquake main shock, 58 of the 108 fires whose cause was identified were electrical.

Official English · Tokyo Metropolitan Government 東京都

“If a power outage occurs during a disaster, unplug appliances and turn off the circuit breaker.” “When evacuating, close the main gas valve, and turn off the circuit breakers.”

“If you notice a burning smell after the power is restored, you should immediately trip the breaker, check the safety again, and stop using the electricity if you cannot identify the cause.”

— 「東京防災」English edition, ch.1 pp.68–69, 80–83: https://www.bousai.metro.tokyo.lg.jp/_res/projects/default_project/_page_/001/029/136/tb2023_e_11.pdf · checked 1 Nov 2026

The FDMA adds two points: when power returns, check appliances, cords and wiring for damage (including water damage) and that nothing flammable is near heaters before using them; and damage inside walls can start a fire long after power returns, so if you see smoke or smell burning, turn the breaker off at once and call 119.

Appliances on a timer may switch on later, at an unusual time (FDMA research centre). The Cabinet Office recommends an earthquake-tripped breaker (感震ブレーカー) that cuts power automatically on strong shaking, for when you are out or have no time to switch off. Several Tokyo wards give these out free or subsidise them: check your ward page.

明かりLight: torches, not candles

Translated · FDMA Fire Research Center 消防研究センター (MIC 総務省)

“Avoid using candles or other naked flames for light as far as possible.” After a quake, things are scattered and flammable items end up where they normally aren’t, so fires start more easily than usual; people are tired, aftershocks may come, and if something catches fire, escaping and putting it out are harder than in a normal fire.

原文 (Japanese original)

明かり取りの目的で、ろうそく等の裸火は極力使用しないでください。地震で物が散乱し、平常時には無い場所に燃えやすいものがあるなど、屋内はいつにも増して裸火から着火しやすい状況にあります。また、避難や復旧活動の疲れから、注意が十分に行き届かない場合があります。余震のおそれもあります。万が一着火した場合には、避難や消火が通常の火災より困難になります。

— 総務省 消防研究センター「地震後の火災防止について（注意喚起）」: https://www.soumu.go.jp/menu_kyotsuu/important/103794_05.html · checked 1 Nov 2026

The Prime Minister’s Office stock list does include candles; TEPCO says to be careful of fire if you use them. Better: the Cabinet Office suggests torches and foot lights in the living room and bedroom, ideally ones that switch on by themselves in a power cut, and glow-in-the-dark tape on stairs. The FDMA says ideally one torch per person (see the home kit article).

スマホ・電話Phones, power banks and landlines

• Landlines usually die too. TEPCO: most land-line and IP phones can’t be used in an outage, so have a mobile and a backup power source.
• Carry a charged power bank as a habit, and keep solar and battery chargers too (Tokyo Bousai pp.88–89).
• Tell family you’re OK via the disaster message dial 171 or your carrier’s message board (practice days: the 1st and 15th of each month, Prime Minister’s Office).
• Power-bank safety (NITE): not in a hot car or direct sun, charge where you can see it (not while out or asleep), and stop if it swells, gets very hot or smells burnt.
• WardReady suggestion: switch on low-power mode early; you don’t know how long the outage will last.

冷蔵庫・食品Fridge and food

Translated · Ministry of Health, Labour and Welfare 厚生労働省

“In a disaster, with lifelines cut, food can no longer be kept cold, which makes food poisoning more likely.”

原文 (Japanese original)

災害時は、ライフラインの寸断により、食品の低温保管ができなくなるなど、食中毒が発生しやすい状況となります。抵抗力が弱い方は重症化することもありますので、しっかり防ぐことが大切です。

— 厚生労働省「災害時の食中毒予防のために」: https://www.mhlw.go.jp/stf/seisakunitsuite/bunya/0000212536_00004.html · checked 1 Nov 2026

• Keep the doors shut. MAFF: leaving the fridge open for a long time or opening it again and again lets warm air in and raises the temperature.
• Eat from the fridge first, then move on to your stock (MAFF, see the home kit article).
• Don’t trust your nose. MAFF: you can’t tell from smell, colour or taste how many food-poisoning bacteria there are. If anything smells or looks off, throw it out.

暑さ・寒さ・換気Heat, cold and fumes

Official English · TEPCO Power Grid 東京電力パワーグリッド

• “Be careful of heatstroke in the summer because air conditioners and electric fans cannot be used during a power outage.”
• “Avoid using briquette or charcoal-fueled cooking stoves for heating or making food indoors. If you must use one, be sure to periodically provide sufficient ventilation in order to prevent carbon monoxide poisoning.”
• “Provide periodic ventilation in the same manner if using any sort of combustion appliance such as an oil heater.”

— What to do if the power goes out: https://www.tepco.co.jp/en/pg/outage/todo-e.html · checked 1 Nov 2026

The Cabinet Office suggests a way to keep warm or cool, and to cook, that works without air conditioning or a microwave; if you use flame, choose heaters and stoves that shut off when knocked over. Anyone using home medical equipment should keep spare batteries or a backup (Cabinet Office, Tokyo Bousai).

マンションApartments: water, elevators, auto-locks

• Water can stop with the power. The Cabinet Office says to prepare for water cuts when water pumps stop in an outage. Keep the drinking and flushing water from your home kit.
• Elevators, auto-locks, automatic doors and multi-storey car parks stop, and security systems and gas-leak alarms may not work (TEPCO).
• After a quake, use the stairs. Tokyo Bousai: even a working elevator may stop suddenly “and you may become trapped.” For a planned outage, TEPCO says don’t use the elevator at that time.

ポータブル電源・発電機Portable power stations and generators 広告 / PR

A portable power station (ポータブル電源) is a big rechargeable battery. A generator (携帯発電機) burns fuel, which makes it far more dangerous:

Translated · Consumer Affairs Agency 消費者庁

Deaths suspected to be from carbon monoxide poisoning have happened when generators were used indoors during outages caused by earthquakes, typhoons and snowstorms. Generators: 1. “Never use indoors.” 2. Never use even outdoors in poorly ventilated places or where fire is used. 3. Keep the distance from buildings set for each product. Portable power stations: 1. Choose a product with a clear maker and seller, and check it can be collected and recycled. 2. Beware of electric shock in use. 3. Check it is not a recalled product.

原文 (Japanese original)

地震、台風、暴風雪の自然災害による停電時など、屋内で携帯発電機を使用したことによる一酸化炭素(CO)中毒が疑われる死亡事故が発生しています。…携帯発電機 1.屋内では絶対に使用しないでください。2.屋外でも、換気の悪い場所・火気を使用する場所では絶対に使用しないでください。3.製品ごとに定められた距離を建物及びその他の設備から離してください。ポータブル電源 1.製造・販売元がはっきりしている製品を選び、また回収・リサイクルに対応しているか確認しましょう。2.使用中の感電に注意しましょう。3.リコール対象製品となっていないか確認しましょう。

— 消費者庁「携帯発電機やポータブル電源の事故に注意!」: https://www.caa.go.jp/policies/policy/consumer_safety/caution/caution_053 · checked 1 Nov 2026

NITE (Japan’s product-safety agency) adds that running a generator in a car or tent is as dangerous as indoors, and that big power stations need extra care: avoid drops and high temperatures, store it in a cool, dark place, and check recalls on NITE SAFE-Lite.

Home ventilator with no backup power? TEPCO says to talk to your medical provider in advance; it may lend a small generator where possible.

Below is WardReady’s shopping help, not official guidance:

停電の言葉Japanese words you’ll see

印刷用カードPrintable blackout card

Print this card ▸

Next: stock water, food and light with the emergency home kit guide, tick off the go-bag & 3-day stockpile checklist, and check your ward’s shelters and free items such as earthquake-tripped breakers: Chiyoda · Chuo · Minato · Shinjuku · Bunkyo · Taito · Sumida · Koto · Shinagawa · Meguro · Ota · Setagaya · Shibuya · Nakano · Suginami · Toshima · Kita · Arakawa · Itabashi · Nerima · Adachi · Katsushika · Edogawa.

出典Sources (checked 2026-11-01)

• TEPCO Power Grid 東京電力パワーグリッド, What to do if the power goes out (English): https://www.tepco.co.jp/en/pg/outage/todo-e.html
• TEPCO Power Grid, Contact Information (English): https://www.tepco.co.jp/en/pg/outage/contact-e.html
• 東京電力パワーグリッド「急に電気が消えたとき」: https://www.tepco.co.jp/pg/consignment/for-general/trouble.html
• 東京電力パワーグリッド「お問い合わせ」(停電情報の更新・チャット): https://www.tepco.co.jp/pg/user/contact.html
• 東京電力パワーグリッド「停電情報」: https://teideninfo.tepco.co.jp/
• FDMA 消防庁「令和5年版 消防白書」3．地震火災への備え: https://www.fdma.go.jp/publication/hakusho/r5/report7/68438.html
• FDMA 消防庁「通電火災対策について」(消防の動き 2020年1月号, PDF): https://www.fdma.go.jp/publication/ugoki/items/rei_0201_48.pdf
• FDMA Fire Research Center 消防研究センター「地震後の火災防止について（注意喚起）」(総務省サイト): https://www.soumu.go.jp/menu_kyotsuu/important/103794_05.html
• Cabinet Office 内閣府「家庭における地震時等の停電対策について」: https://www.bousai.go.jp/jishin/syuto/denkikasaitaisaku/teidentaisaku.html
• Cabinet Office 内閣府 停電対策チラシ「大規模地震発生！どうする？」(PDF): https://www.bousai.go.jp/jishin/syuto/denkikasaitaisaku/pdf/teiden_low.pdf
• Cabinet Office 内閣府「大規模地震時の電気火災の発生抑制に関する検討会」電気火災対策・感震ブレーカー: https://www.bousai.go.jp/jishin/syuto/denkikasaitaisaku/index.html
• Tokyo Metropolitan Government 東京都「東京防災」English edition (2023 revision), ch.1 (PDF), pp.34–35, 66–69, 80–83, 86–89: https://www.bousai.metro.tokyo.lg.jp/_res/projects/default_project/_page_/001/029/136/tb2023_e_11.pdf
• Prime Minister’s Office of Japan 首相官邸「災害への備え 事前にできること」(page updated Oct 2026): https://www.kantei.go.jp/jp/headline/bousai/sonae.html
• Consumer Affairs Agency 消費者庁「携帯発電機やポータブル電源の事故に注意!」: https://www.caa.go.jp/policies/policy/consumer_safety/caution/caution_053
• NITE 製品評価技術基盤機構 製品安全情報マガジン Vol.459「災害時の事故」: https://www.nite.go.jp/jiko/chuikanki/mailmagazin/2024fy/vol459_240827.html
• NITE 製品安全情報マガジン Vol.506「リチウムイオン電池搭載製品の事故」(Aug 2026): https://www.nite.go.jp/jiko/chuikanki/mailmagazin/2026fy/vol506_260807.html
• Ministry of Health, Labour and Welfare 厚生労働省「災害時の食中毒予防のために」: https://www.mhlw.go.jp/stf/seisakunitsuite/bunya/0000212536_00004.html
• MAFF 農林水産省「冷蔵庫のかしこい使い方」: https://www.maff.go.jp/j/syouan/seisaku/foodpoisoning/frige.html
• US Centers for Disease Control and Prevention (CDC), Keep Food Safe After a Disaster or Emergency (US source, Nov 2025): https://www.cdc.gov/food-safety/foods/keep-food-safe-after-emergency.html