What a shutoff actually looks like
Shutoffs happen on the worst fire-weather days: high wind, low humidity, often in winter or early spring when you still need heat. The March 14, 2026 event hit roughly 14,400 customers in Boulder County and about 3,400 in Jefferson County. Restoration waits until crews can patrol the lines, which is why outages can stretch past 24 hours.
Plain grid-tied solar shuts down when the grid does — that’s a safety requirement, not a flaw. To keep power, you need a battery and equipment that can isolate your home from the grid.
How long a battery lasts
A single Tesla Powerwall 3 stores 13.5 kWh. Running the essentials — refrigerator, furnace blower, internet, lights, phone charging — it can often last a day or more; running an electric range, dryer, and central air, it drains in hours. With solar, the battery recharges during the day, which is what turns a one-day battery into multi-day resilience when the sun cooperates.
The blackout-runtime calculator has a 72-hour shutoff preset. Pick the loads you actually need and see how many batteries that takes. Most households find a critical-loads design with one or two batteries covers them.
Battery versus generator
Generators run longer if you keep refueling them and cost less upfront. Batteries switch over automatically, run silently, make no exhaust, don’t need fuel stored during a fire emergency, and earn their keep on non-outage days by covering Xcel’s 5–9 pm on-peak window. Some households keep a small generator as a last-resort backup to the battery; that’s a reasonable belt-and-suspenders approach.
Cost and incentives, as of September 2026
Powerwall 3 runs about $19k installed for the first unit and about $12k for each additional. Enphase starts around $17k for 10 kWh, and SigEnergy around $15.5k for 9 kWh. Colorado offers a 10% state income-tax credit on home batteries for tax years through 2026, and batteries are exempt from state sales tax. Batteries owned through a lease keep federal §48E eligibility through 2033. Verify current terms before counting on any incentive.
What to do next
- 1Sign up for your utility’s outage and shutoff alerts so you get advance notice.
- 2List the loads you can’t lose — heat, refrigeration, medical devices, well pump, internet.
- 3Run the blackout-runtime calculator with the 72-hour preset.
- 4Ask us for a critical-loads battery design, with or without solar, and pricing for one versus two batteries.
- 5Keep a plan for the first shutoff before your system is installed: a charged power bank, a cooler, and a way to keep medications cold.
FAQ
Questions we hear
Will my solar panels work during a power shutoff?
Not without a battery or a backup-capable system. Grid-tied inverters shut off when the grid goes down to protect line workers. A battery with an automatic transfer lets solar keep running and recharging during the day.
How many Xcel customers have been affected by wildfire shutoffs?
About 50,000 in December 2025 and about 18,000 on March 14, 2026, across parts of Boulder, Jefferson, Larimer, Weld, and Clear Creek counties.
Can one Powerwall run my whole house for a 72-hour shutoff?
Usually not the whole house without solar recharging. For essentials only, one battery plus solar can often carry a household through, weather permitting. The runtime calculator shows your specific loads.
Should I get a battery or a generator for shutoffs?
A battery is automatic, silent, and saves money every weekday evening on time-of-use rates. A generator costs less and runs as long as you have fuel. Some homes use both.
Do I need to be home for the battery to take over?
No. When the grid drops, the system isolates your home and switches to battery automatically, typically fast enough that most devices don’t notice.