The February 2021 deep freeze that pushed temperatures far below zero across Montana is the kind of event the state’s grid dreads — extreme cold, ground blizzards, and high wind straining lines from Billings to Missoula to Bozeman right when a working furnace matters most. Montana runs on the Western grid through NorthWestern Energy, Avista, and rural cooperatives, spread thin across one of the least densely populated states in the country, so a downed rural feeder can wait on crews. And winter is only half the story: wildfire season brings its own shutoffs and outages. If you’re looking at solar in Montana, know that a grid-tied rooftop array shuts off during any of those outages unless you also have storage.
Two seasons, two kinds of outage
Montana homeowners plan around a split threat. In winter it’s cold and wind — blizzards and ice pulling lines down when the temperature is the real danger. In summer and fall it’s fire — heat, drought, and shutoffs across NorthWestern and co-op territory. A single battery covers both, and it’s quieter and simpler than the gas generator idling in the driveway.
The outages Montana actually gets
Montana’s power comes from NorthWestern Energy, Montana-Dakota Utilities and rural electric co-ops, and most of the state sits inside the Western Interconnection. What makes an outage here different is not the hazard list. It is the geography.
Distance is the defining problem. Montana has some of the longest rural distribution feeders in the country, and a repair crew may be hours away before it starts work, with the roads open. On a ranch or an acreage the honest planning assumption is a night on your own at minimum, and often longer.
Extreme cold and Arctic outbreaks. An Arctic outbreak parks temperatures far below zero for days at a stretch. That raises the stakes of losing the grid, because a house without a furnace blower starts risking pipes rather than comfort.
Wind. High plains wind and the gusts off the Rocky Mountain front take down lines and drop trees across them, over long spans where every failure is a separate truck roll.
Heavy wet snow. Spring and autumn storms load lines and branches with snow weighing several times what January powder does, which snaps poles rather than tripping a breaker.
Wildfire and smoke. Late summer brings fire that can burn through infrastructure outright, plus public safety power shutoffs, where a utility de-energises lines in extreme fire weather to keep a spark from starting one. A shutoff is the one outage that arrives with notice, which is exactly when a charged battery and staged panels pay for themselves.
The same long-feeder arithmetic runs across the state line in our North Dakota guide.
The essentials, and what they draw
Most homes overestimate what they need. A fridge runs about 150W, ten LED bulbs roughly 50W together, a router near 10W, and phone charging about 20W — near 300W of steady draw to keep the core of a home going. The Solar Generator HomePower 3000 (about 3,072Wh, 3,600W) handles that for one to two days and ships with solar panels to recharge during daylight, so it can last as long as the outage does.
▶ Shop the HomePower 3000 — panels included use code DEAL5
How long each Jackery runs a Montana home’s essentials
Size against watt-hours a day, not the wattage on the label.
| Load | Typical draw | Energy per day |
|---|---|---|
| Fridge | ~150W running (cycling) | 1,000 to 1,500Wh |
| Chest freezer | cycling | 600 to 900Wh |
| Gas furnace blower + ignition | 400 to 600W while running | 3,000 to 5,000Wh in deep cold |
| Wi-Fi router | ~10W | ~240Wh |
| LED lights (ten bulbs) | ~50W | ~300Wh (6 hours) |
| Phones and a laptop | 20 to 60W | 150 to 300Wh |
| CPAP | 30 to 60W | 300 to 500Wh per night |
| Well pump | ~1,000W running, 2 to 3x that to start | needs 240V |
| Engine block heater | 400 to 1,000W | one hour before starting, not overnight |
| Fan (smoke season, windows shut) | 30 to 60W | ~400Wh |
| Space heater | 1,500W | the wrong plan, see below |
Two rows deserve a plain warning. A 1,500W space heater drains a 3,000Wh battery in about two hours, so it is the wrong plan at 20 below; run the furnace blower and heat the whole house instead. Plug the engine block heater in for the hour before you start the truck, never all night.
Fridge, router, lights and phones come to roughly 2,000Wh a day. Add the furnace blower in an Arctic outbreak and the day runs 5,000 to 7,000Wh. A smoke-season shutoff with the fridge, a fan, the router and phones is nearer 1,800Wh.
HomePower 3000. 3,072Wh of LiFePO4 and 3,600W of output, panels included. Essentials for one to two days per charge, or closer to a day with the furnace blower on top. Near 30 dB with zero exhaust, so it runs indoors with the house shut against cold or smoke. It is 120V only and not expandable.
HomePower 3600 Plus. 3,584Wh and 3,600W, expandable to 21kWh, which turns a 6,000Wh furnace-plus-essentials day into three days or more with no sun at all. It is transfer-switch ready, so the furnace circuit can be hardwired. This is the unit for a place at the end of a long co-op feeder.
Solar Generator 5000 Plus. 5,040Wh, 7,200W, 120V and 240V, expandable to 60kWh. The only one of the three that runs a 240V well pump.
A bright summer day puts 1,500 to 2,000Wh back through the panels, which is why a wildfire-season shutoff is the easy case. A grey winter day returns a few hundred watt-hours, so size for January as if the sun gives you nothing.
| Unit | Capacity / output | Best for in Montana | Buy |
|---|---|---|---|
| HomePower 3000 (our pick) | 3,072Wh · 3,600W · panels included | Essentials for 1 to 2 days; furnace blower for about a day | Check price → |
| HomePower 3600 Plus | 3,584Wh · 3,600W · to 21kWh | Multi-day Arctic outbreaks, furnace on a transfer switch | Check price → |
| Solar Generator 5000 Plus | 5,040Wh · 7,200W · 120V/240V · to 60kWh | Well pump and other 240V loads on a ranch | Check price → |
▶ Shop the HomePower 3600 Plus — expandable to 21kWh
Why a sealed battery wins in a Montana cold snap
Running an engine in an attached garage isn’t safe, and refueling one outdoors at 20 below isn’t realistic. A Jackery LiFePO4 station removes both problems: zero emissions, near 30 decibels, safe indoors, and no fuel to store or spill. For a larger home in Helena or Great Falls, or to carry heavier loads through a longer winter or wildfire-season outage, the Solar Generator 5000 Plus steps up to 5,040Wh and 7,200W with 120V and 240V, expandable to 60kWh.
▶ Shop the Solar Generator 5000 Plus — 7,200W, 120V/240V
Solar generator vs gas generator in a Montana winter
- Carbon monoxide. A battery station vents nothing, so it runs in the utility room with the house sealed. A gas generator has to sit outside, away from windows and doors, in the weather that caused the outage. Never run one in an attached garage, and never backfeed a wall outlet.
- Noise. About 30 decibels against 60 to 90.
- Fuel in a storm. The battery is full before the storm and refilled by the sun afterward. Gasoline has to be stored fresh and poured into a hot engine in blowing snow, and the nearest station may be thirty miles away and dark.
- Cold starting. Press a button, or fight a pull cord and cold oil at 20 below.
- Maintenance. Oil, carburetor, fuel stabiliser and a monthly test run for gas. A monthly charge check for the battery.
- Running cost. Sunlight is free. Three days of gasoline is not, and in Montana neither is the drive.
- What a gas generator still does better. A very long outage with no sun, and cheap whole-house 240V up front. On a ranch, a gas generator outdoors for the heavy 240V work plus a battery indoors for the quiet overnight loads is the strongest pairing.
Set-up checklist before the first storm
- Charge it to full, then top it up monthly. Check the display on the first of the month, and again whenever fire weather is in the forecast.
- Keep it indoors and above freezing. A closet, utility room or basement, never an unheated garage or the shop.
- Write the load order down. Fridge first, then the furnace blower, then the router and one lamp per room. Tape the list to the unit.
- Buy cords rated for the load. A short 12-gauge cord for the fridge and furnace runs; thin cords drop voltage and get warm.
- Test the furnace on the battery in October. If it is hardwired, have a licensed electrician add a plug-in connection first.
- Store the panels where you can reach them and set them up on the south side without shovelling out a shed.
- Pair the HomePower 3600 Plus with a transfer switch for hardwired circuits like the furnace or well pump controls. Licensed electrician only, and never backfeed an outlet.
- Keep a battery-powered CO alarm regardless. A furnace, a water heater, or a neighbour’s generator can still put carbon monoxide in the house.
▶ Get the HomePower 3000 charged before the first cold snap use code DEAL5
Set it up before a blizzard or fire threat is in the forecast, keep it charged, and it’s ready the moment the grid drops. It’s worth checking current deals first.
Keep reading: Montana solar incentives & costs · How to keep your fridge & lights on in an Idaho outage · Solar battery backup vs rooftop solar (Washington) · How to keep power during a North Dakota outage · How to keep power during a Wyoming outage · How to size a solar generator for home backup