Guides · Grid-down
The 90-day grid-down plan
How a household gets through three months without grid power, built on what federal planners, utilities and public health agencies have published.
By PowerLockdown EditorialUpdated November 1, 20267 min readHow we research
In this guide
DisclosureAs an Amazon Associate we earn from qualifying purchases. We may earn a commission when you buy through links on this site, at no extra cost to you. Learn more.
At a glance
- This is a planning scenario, not a forecast. No agency predicts a 90-day regional outage. FEMA plans for outages lasting "weeks or months" because the damage would be severe if one happened. Seen posts about a 90-day shutdown? Here is what is actually known.
- The slow part is big equipment. DOE found large power transformers took 5 to 16 months to deliver in 2010, and up to five years in extreme cases.
- You cannot store 90 days of everything. The plan shifts from storage to treatment and production: filtering water, cooking from bulk staples, cutting wood, managing waste.
- Sanitation becomes a health issue. Oregon State University Extension warns that poorly handled waste spreads cholera and salmonella.
- Medicine is the hardest gap. Work out refills, storage limits and powered devices with your prescriber before anything happens.
- Neighbors are the multiplier. CERT, ARES and street-level check-ins turn 20 isolated households into one block that functions.
What could cause a 90-day outage
Long regional outages need damage that cannot be fixed by rerouting power or swapping parts from a warehouse. Three scenarios appear in federal and industry planning documents.
- A severe geomagnetic storm. NOAA's G5 "extreme" level says "some grid systems may experience complete collapse or blackouts. Transformers may experience damage." NOAA counts about 4 G5 storms per 11-year solar cycle. The March 1989 storm blacked out Québec for more than nine hours and damaged a 500 kV transformer beyond repair at New Jersey's Salem nuclear plant. Full detail in solar storms and the power grid.
- A high-altitude electromagnetic pulse. The EMP Commission's 2004 report warned of "recovery times of months to years." EPRI's 2019 study found immediate, widespread transformer damage "is not expected" but a multi-state regional blackout is possible. The two disagree; we cover both in EMP and the power grid.
- Coordinated physical or cyber attacks. See attacks on the power grid for the record so far.
The common thread is large power transformers. DOE's 2014 study says they weigh 100 to 400 tons, and that U.S. dependence on imports was "much greater than 85 percent" for units rated 345 kV and above. Wood Mackenzie estimated in August 2025 that U.S. power transformer supply was running 30% short of demand. Losing many at once is what turns a week-long outage into a season.
A real event shows the smaller version. On December 3, 2022, gunfire disabled two Duke Energy substations in Moore County, North Carolina. About 45,000 customers lost power. The county hospital ran on generators, schools closed, and repairs took until December 7, with the last customers back early on December 8 (WUNC, AP). That was two substations and about five days. Scale it up and the 90-day planning case is easy to picture.
The three phases
| Phase | Goal | Main jobs |
|---|---|---|
| Days 1–14 | Live on what is stored | Water from storage, eat perishables first, set up warm room, CO alarms, two-bucket toilet, check on neighbors |
| Days 15–45 | Switch to treatment and routine | Filter and disinfect water, cook from bulk food, schedule charging, start waste storage area, join a block network |
| Days 46–90 | Sustain and share | Steady water source, rotate food, fuel and wood management, health checks, pool skills and tools with neighbors |
Water: from storage to treatment
At CDC's 1 gallon per person per day, 90 days for a family of four is 360 gallons. Few homes can store that. Store what you can for the first phase, then plan on treating water from another source.
- 01Store 14 days or more of water per person, matching Oregon's 2 Weeks Ready standard.
- 02Identify the closest reliable source: a well with a hand pump or solar pump, a spring, a stream or a lake. CDC says water contaminated by fuel or toxic chemicals cannot be made safe, so avoid runoff from roads and industrial sites.
- 03Settle or filter cloudy water, then disinfect. CDC: boil 1 minute (3 minutes above 6,500 feet), or add 8 drops of 5–9% unscented bleach per gallon and wait 30 minutes.
- 04Use a gravity filter for volume. CDC notes portable filters do not remove viruses, so disinfect after filtering.
No. 1Water storage
WaterPrepared Blue 55 Gallon Water Storage Tank
Best for: Storing a month or more of household water in one footprint
- 55 gallons; 22 × 28 × 30 in
- HDPE, BPA free, FDA/NSF approved, UV-resistant blend (manufacturer)
- Built-in spigots that fit a standard garden hose, plus utility valves
- Large fill cap; stackable
Tradeoffs
- About 460 lb when full (55 gal × ~8.3 lb, our arithmetic), so fill it where it will stay
- No pump or water treatment included in this listing
No. 2Water treatment
Platypus GravityWorks Water Filter System, 4.0 L
Best for: Filtering household volumes without pumping or squeezing
- 0.2-micron hollow-fiber filter; filters up to 1.75 liters per minute (manufacturer)
- Removes 99.9999% of bacteria and 99.9% of protozoa (manufacturer)
- Filter life up to 1,500 L
- 4.0 L dirty reservoir plus 4.0 L clean reservoir; 11.5 oz
Tradeoffs
- Manufacturer spec table lists it as not effective against viruses: boil or disinfect when viruses are a concern
- Hollow fibers can be damaged if the filter freezes while wet
No. 3Water treatment
Sawyer Squeeze Water Filter System (SP129)
Best for: Reusable all-rounder: squeeze, gravity or on a bottle
- 0.1-micron absolute hollow-fiber filter
- Removes 99.99999% of bacteria and 99.9999% of protozoa such as Giardia and Cryptosporidium (manufacturer)
- Filter about 3 oz
- Reusable BPA-free collapsible pouch
- Lifetime limited warranty
Tradeoffs
- No virus claim: disinfect after filtering if viruses are a concern
- Manufacturer page lists no filter life in gallons
More detail, including water already inside your house, is in water when the taps stop.
Food: three layers
At 2,000 calories a day, one adult needs 180,000 calories for 90 days. Layer it.
- Layer 1, days 1–14: fridge and freezer food first, then pantry canned goods you already eat.
- Layer 2, days 15–45: long-shelf-life buckets and freeze-dried meals. They cost water and cooking fuel, so count both.
- Layer 3, days 46–90: bulk staples. Utah State University Extension reports white rice can last up to 30 years sealed oxygen-free in cool storage, and dry beans 10 years or more in #10 cans or Mylar with oxygen removed.
No. 1Emergency food
Legacy Food Storage 120 Serving Breakfast, Lunch and Dinner Bucket (CB0120)
Best for: A deep bulk layer: about 23 person-days at 2,000 calories
- 120 servings in 30 Mylar pouches: 40 breakfast, 80 entree
- Average 395 calories per serving; manufacturer lists 23.7 "2,000 calorie days"
- Shelf life of up to 25 years (manufacturer)
- 31 lb, one bucket
Tradeoffs
- Meals need water and a heat source; the pancake mix also needs oil
- The page's stated calorie total does not match its per-serving figure, so plan on the 2,000-calorie-days number
No. 2Emergency food
Mountain House Classic Assortment Bucket
Best for: Longest shelf-life claim with familiar meals
- 12 pouches (24 servings)
- 210–300 calories per serving; about 6,140 calories total (our sum from the listed pouch calories)
- Needs 18 cups of water total
- 5.52 lb
- 30-year shelf life and taste guarantee from date of manufacture (manufacturer FAQ)
Tradeoffs
- About 3 person-days at 2,000 calories a day despite "24 servings"
- Best with hot water
Storage temperatures, rotation and calorie math are in long-term food storage.
Heat and power
In a cold-season outage, heat decides whether the house is livable. A properly installed, inspected wood stove burning dry wood is the most sustainable option for three months. EPA's Burn Wise program says wood burns best below 20% moisture and should season at least six months, so wood cut in an emergency will not burn well for a long time. Indoor-safe propane heaters bridge the gap. See heating without power.
For electricity, fuel runs out and supply chains stall: FEMA's annex says fuel will need to be prioritized for distribution. Solar recharging is the only power source that resupplies itself. Size it with the backup power calculator and compare kits in best solar generator kits.
Sanitation
EPA lists sewage backups as a consequence of utility power loss. Oregon State University Extension's two-bucket method separates urine from feces, covers each deposit with sawdust or similar carbon material, and stores sealed feces bags apart from other garbage. It warns that cholera and salmonella spread when waste is handled poorly. Set the system up in week one. Full method: sanitation without power.
No. 1Sanitation
Reliance Luggable Loo Portable Toilet (5 gallon)
Best for: A real seat on the poo bucket of a two-bucket toilet
- 5-gallon bucket; seat and cover snap on and off
- 220 lb weight capacity; metal handle
- 15.75 × 14.5 × 15 in; 2.96 lb
- Fits Reliance Double Doodie waste bags (manufacturer)
Tradeoffs
- A bucket with a seat: no tank or seal, so it needs liners and cover material for odor
- Reliance's own store showed it unavailable on our check; Amazon listed it in stock
No. 2Sanitation
Reliance Double Doodie Waste Bags
Best for: Sealed, double-bagged waste for bucket toilets
- 6 bags per package; each holds up to 5 lb of waste
- Inner roll-up waste bag plus outer bag with leak-proof double zip lock
- Puncture resistant; fits the Luggable Loo and most portable toilets (manufacturer)
Tradeoff
- Six uses per pack: a household of four needs many packs for a long outage
Medical
- Ask your prescriber and insurer about the longest refill they will allow, and keep the list of medicines and doses on paper.
- FDA says insulin vials and cartridges can stay unrefrigerated at 59–86°F for up to 28 days. Past that, you need a way to keep it cool or a resupply plan.
- FDA's disaster guidance says a life-sustaining drug stored outside its proper temperature "may be used until you can get a new supply"; ask a pharmacist when you can.
- In Texas in February 2021, 25 deaths came from worsening illness linked to lost power for oxygen, dialysis disruptions and frozen devices or medication (Texas DSHS). Plan power for medical devices first.
- Stock a full first aid kit and learn to use it. See emergency first aid and medical prep.
No. 1First aid and medical
American Red Cross (made by First Aid Only) Deluxe All Purpose First Aid Kit, 299 pieces
Best for: An all-purpose home kit
- 299 pieces in a soft zippered case with clear pockets; 1.3 lb
- 75 plastic bandages, 50 junior bandages, 5"×9" trauma pad
- Alcohol pads, BZK antiseptic towelettes, antibiotic ointment packs
- Aspirin, non-aspirin pain reliever and ibuprofen packets
- Thermometer, emergency blanket, cold compress, scissors, tweezers, nitrile gloves, Red Cross First Aid Guide
Tradeoffs
- Mostly small-wound supplies; only one trauma pad
- No CPR face shield listed
No. 2First aid and medical
FRIO Individual Cooling Wallet
Best for: Keeping an insulin pen cool without a fridge
- Holds one insulin pen, two 3 ml cartridges or three 1.5 ml cartridges
- Manufacturer: minimum continuous cool period of 45 hours
- Activated with cold water; recharges in under 5 minutes
- Inner wallet 18 × 6 cm
Tradeoffs
- Evaporative cooling, not refrigeration
- Frio states 18 to 26°C (64.4 to 78.8°F) inside for at least 45 hours at a constant 100°F, which is not fridge-cold
Security basics
- Keep supplies out of sight. Do not post about stockpiles. Bring generators and fuel cans inside a locked shed or behind a fence when not running, keeping the 20-foot rule while they run.
- Use lanterns indoors and keep exterior lighting modest so the house does not stand out on a dark street.
- Organize a street watch with neighbors you trust, with set radio check-ins.
- Report suspicious activity to local law enforcement and call 911 for emergencies. CISA and DOE ask people living near substations to report unusual photography or surveillance.
Community
No household stores 90 days of everything. FEMA's Community Emergency Response Team program trains volunteers in fire safety, light search and rescue and disaster medical operations. ARRL's Amateur Radio Emergency Service registers licensed hams to provide communications "when storms or other disasters damage critical communication infrastructure." Oregon's 2 Weeks Ready program builds the same habit at the household level. Join one before you need it, and see ham and GMRS radio for how a block stays in touch without towers.
No. 1GMRS radio
Midland GXT67 PRO 5-Watt GMRS Two-Way Radio
Best for: Household and neighborhood talk with repeater access
- 5 watts; repeater capable with 8 GMRS repeater channels and split tones
- Up to 99 GMRS/FRS channels (22 standard, 28 preset privacy-code, up to 49 user-defined)
- IP67 waterproof and dustproof
- NOAA weather alert; up to 4-day battery life, 4-hour rapid charge (manufacturer)
Tradeoffs
- Transmitting on GMRS requires an FCC license (47 CFR 95.1705); the manufacturer page does not say so
- Sealed battery is not user-replaceable
No. 2Emergency radio
Midland ER310 Emergency Crank Weather Radio
Best for: A household weather radio with several ways to stay powered
- Power: solar, hand crank, 3,500 mAh rechargeable Li-ion, or 6 AA batteries
- NOAA weather band; alerts sound when issued on your local channel
- LED flashlight with SOS beacon
- USB output to top up a phone
Tradeoffs
- Midland notes the design dates to the early 2000s and may not charge newer phones (iPhone X and later) reliably. Weather alerts are not SAME county-coded.
- Midland's FAQ notes solar tops up a charged battery rather than reviving a dead one
- Micro-USB charging rather than USB-C
No. 3Lantern
Goal Zero Lighthouse 600 Lantern & USB Power Hub
Best for: Rechargeable whole-room lantern with a hand-crank backup
- 600 lumens, warm white (3,500K)
- 5,200 mAh / 18.98 Wh Li-ion battery
- Recharge by USB (about 6 hrs), Goal Zero Nomad 10 solar panel (about 6 hrs) or built-in hand crank
- 1 minute of cranking = about 10 minutes of light on low
- USB-A output (5V, 1.5A) to top up a phone
- Runtime: one side on low up to 320 hrs; both sides on high 2.5 hrs
- 1.1 lb (498 g)
Tradeoffs
- Only about 2.5 hours at full brightness on both sides
- Crank gives little light per minute; solar recharge needs a separately sold panel
What we don't know
Nobody can say how long a severe regional outage would last. The EMP Commission and EPRI reach very different conclusions about recovery from an EMP. NERC reported that the grid stayed stable through the May 2024 G5 storm, which was weaker than 1989. We found no current public federal count of spare large transformers. Transformer lead times in the DOE study date from 2010 and may have lengthened since, given the 2025 supply deficit. Plan for 90 days because it forces durable systems, not because evidence says it will happen.
Start smaller: the 30-day plan, the blackout checklist and the Blackout Kit.
Frequently asked questions
- Is a 90-day grid outage realistic?
- It is a planning scenario. No agency forecasts one, but FEMA's 2017 annex plans for outages lasting weeks or months, and NOAA's G5 storm description includes grid collapse and transformer damage. Preparing for 90 days builds systems that cover shorter outages easily.
- How much water does a 90-day plan need?
- At 1 gallon per person per day, 90 gallons per person. Most homes cannot store that, so store at least two weeks and plan to filter and disinfect water from another source for the rest.
- Why would repairs take months?
- Large power transformers are custom, weigh 100 to 400 tons and mostly come from overseas. DOE found lead times of 5 to 16 months in 2010, longer in extreme cases. Losing many at once would strain replacement capacity.
- What is the most overlooked part of a long-outage plan?
- Sanitation. When sewer service fails, waste has to be separated, covered and stored safely. Oregon State University Extension publishes a two-bucket method built for exactly this.
- Should I prepare alone or with neighbors?
- Both. Store your own supplies, then join CERT, ARES or a street network so skills, tools and information are shared.
Sources
- FEMA, Power Outage Incident Annex: Managing the Cascading Impacts from a Long-Term Power Outage, June 2017.
- NOAA Space Weather Prediction Center, NOAA Space Weather Scales, accessed October 31, 2026.
- U.S. Department of Energy, Large Power Transformers and the U.S. Electric Grid, April 2014.
- Wood Mackenzie (press release), Power transformers and distribution transformers will face supply deficits of 30% and 10% in 2025, August 14, 2025.
- Congressional EMP Commission, Report of the Commission to Assess the Threat to the United States from EMP Attack, Vol. 1: Executive Report, 2004.
- EPRI Journal, A "Deliberate Approach" to Electromagnetic Pulses, June 20, 2019.
- WUNC / WFAE, Repairs complete on Moore County substations, December 8, 2022.
- AP via PBS NewsHour, Duke Energy repairs all equipment damaged in North Carolina weekend shooting, December 7, 2022.
- CDC, How to Make Water Safe in an Emergency, September 19, 2024.
- Oregon Department of Emergency Management, Be 2 Weeks Ready, accessed October 31, 2026.
- Oregon State University Extension, Survival Basics: Sanitation and Waste Management (EM 9334), October 2021.
- U.S. EPA, Best Wood-Burning Practices (Burn Wise), last updated October 13, 2026.
- U.S. Consumer Product Safety Commission, Carbon Monoxide Information Center, accessed October 27, 2026.
- U.S. Consumer Product Safety Commission, Keep Warm and Safe This Winter: Tips for Using Generators, Furnaces and Space Heaters, January 23, 2026.
- U.S. EPA, Incident Action Checklist: Power Outages, 2019.
- Utah State University Extension, Storing White Rice, accessed October 31, 2026.
- Utah State University Extension, Storing Dry Beans, accessed October 31, 2026.
- Texas Department of State Health Services, February 2021 Winter Storm-Related Deaths: Texas, December 31, 2021.
- NERC staff report, May 2024 Geomagnetic Disturbance Event Review, January 2026.
- Hydro-Québec, In March 1989, Québec experienced a blackout caused by a solar storm, accessed October 31, 2026.
- Congressional EMP Commission, Report of the Commission to Assess the Threat to the United States from EMP Attack: Critical National Infrastructures, April 2008.
- U.S. Food and Drug Administration, Information Regarding Insulin Storage and Switching Between Products in an Emergency, current as of September 28, 2026.
- U.S. Food and Drug Administration, Safe Drug Use After a Natural Disaster, current as of September 1, 2026.
- FEMA, Community Emergency Response Team (CERT), updated April 22, 2026.
- ARRL, Amateur Radio Emergency Service (ARES), accessed October 31, 2026.
- CISA and DOE, Sector Spotlight: Electricity Substation Physical Security, February 2023.
Related guides
Grid-down
The 30-day grid-down plan
What stops working in a month-long regional outage, how much to store for your household, and what to do each week until the power returns.
Updated November 1, 2026 · 8 min read
Grid-down
Solar storms can damage the grid's biggest transformers
NOAA's own scale says an extreme geomagnetic storm can collapse some grid systems; here is the history, the safeguards and the household plan.
Updated November 1, 2026 · 9 min read
Grid-down
EMP and the power grid: the evidence, the dispute and your options
Federal commissions warn an EMP attack could darken a region for months or longer, utility researchers expect less, and households can do more about the outage than the pulse.
Updated November 1, 2026 · 8 min read
Grid-down
Sanitation without power: build the emergency toilet before you need it
A long outage can stop sewage pumps and treatment, and a two-bucket toilet with a 30-day supply of bags, cover material and sanitizer keeps waste contained and the household healthy.
Updated November 1, 2026 · 8 min read