Colorado Peak Power
Colorado Peak Power
List what you'd run in an outage. The calculator adds up the running watts, the starting surge, and the kilowatt-hours, corrects generator output for your elevation, and shows which of the three ways to back up a Colorado home fits: a portable power station, a generator, or an installed battery or standby system.
Generators lose power at altitude. Thinner air means less oxygen to burn. Here's what a generator labeled 7,500 running watts actually delivers on gasoline:
About 3.5% lost per 1,000 ft, the figure Generac, Cummins, Briggs & Stratton, Champion, and Honda publish (Kohler uses 4%). Battery power stations don't lose output with elevation.Brands sized and compared here, independent of all of them. Compare all 15
Check what you'd want running and adjust the hours if you like. Watts are typical figures from generator sizing charts, on the conservative side; your appliances' labels are the final word.
What you'd run during an outage
| Appliance | Running W | Starting W | Hours/day |
|---|
Your home
Starting watts = everything running plus the single biggest motor start, the standard sizing method. Battery estimates assume about 85% usable after inverter losses.
Each one is checked against your list above. They aren't mutually exclusive; plenty of homes pair a power station for the fridge and internet with a generator for longer outages.
Some product links on this page are affiliate links. If you buy through them, Colorado Peak Power may earn a commission at no cost to you. It doesn't change what the calculator recommends, and we list products by how well their specs match your numbers. Specs are from the manufacturers as of October 2026; check the product page before you buy.
At least 20 feet from the house, exhaust pointed away from doors and windows, never in a garage even with the door up. Carbon monoxide poisoning after storms is common enough that the CDC tracks it every year. Put battery CO alarms on every floor.
A "suicide cord" plugged into a dryer outlet can energize the street's lines and kill a utility lineworker. Connecting a generator to your panel takes a transfer switch or an interlock kit with an inlet box, installed by a licensed electrician and inspected.
No fumes, so they can sit next to the fridge or the furnace. Keep them above freezing; most lithium units won't charge in the cold, which matters in an unheated garage.
Modern furnace control boards can be fussy about the waveform. Inverter generators and power stations produce clean output; many open-frame generators don't. Ask before you plug a furnace into one.
Xcel began proactively cutting power across parts of the Front Range and foothills during high-wind, high-fire-danger days in 2024, affecting tens of thousands of customers at a time. They're usually announced ahead and sunny, so a power station recharged by solar does well.
Snow on leafed-out trees brings down lines along the Front Range. Cold, cloudy, sometimes days long. This is where a generator earns its keep, or a battery big enough to carry the furnace blower overnight.
Mountain co-op customers on long feeds through timber see more outages and slower restoration. Altitude makes generators weaker exactly where they're needed most, so size up or lean on batteries.
Ended for systems installed after December 31, 2025. Portable power stations and generators were never eligible.
Leased or third-party-owned home batteries can still carry a business credit the installer claims and prices in. Compare the monthly payment and buyout terms.
Xcel's Renewable Battery Connect pays enrolled home-battery owners in exchange for limited use of the battery on peak days. Terms change; an installer will have the current ones.
Qualifying solar equipment is exempt from state sales tax. Generators and stand-alone power stations generally are not.
Add the running watts of everything you want on at once, then add the single largest starting surge. That's the label rating to look for at sea level. In Denver a generator delivers roughly 82% of its label (manufacturers publish about 3.5% less per 1,000 feet), so divide by 0.82. The calculator does this for your own list and elevation.
No. Elevation affects engines, not batteries. Cold is what matters for batteries, so keep a power station indoors.
A gas furnace blower, yes, and it's one of the best uses of one. Plan on roughly 300 to 900 watts while the blower runs. A 2 kWh station covers a night or so; a 4 kWh station with an expansion battery covers a day or more. Electric heat is a different scale.
Not by themselves. Grid-tied systems shut off when the grid does. You need a home battery with a backup gateway, or a separate backup source.
A natural gas standby generator runs as long as the gas does and handles big loads like central air. A home battery is silent, needs no fuel or maintenance, and works with solar, but it runs out. Many Colorado mountain homes end up with both. An installer can quote either; use the form below.
Colorado Peak Power is an independent guide and referral service. Some product links pay us a small commission, and licensed installers pay a referral fee when they take on an install request. Neither changes your price, and neither changes the math above.
Not sure which way to go, or ready for someone to quote an install? Answer a few quick questions. It picks up your calculator numbers, points you to the right product if you'd rather do it yourself, and gets the right installer or electrician to call you if you'd rather not.
