Backup generator cost

Quotes vary wildly because they're bundling different things. Break any bid into five buckets: the unit, the electrical (transfer switch, wiring, possibly a subpanel at $530-$2,000 or a dedicated circuit at $500-$1,000), the fuel line, the pad (concrete runs about $50-$75 per square foot), and permits at $50-$200 each. Two quotes that look $3,000 apart are usually two different scopes.

Size drives price hard. Bob Vila's 2026 figures put small 1-6 kW units at $500-$1,800, mid-size 14-18 kW at $4,000-$5,500, and 26-32 kW at $6,500-$15,000. Going up a size class "just in case" is one of the most common ways homeowners overspend. Size to the load you actually need backed up, not to the house's square footage.

Then there's the cost of running it. Bob Vila estimates roughly $90 a day to run a 21 kW natural gas unit, about $175 a day for a 20 kW diesel, and about $220 a day for a 20 kW propane unit. Over a week-long outage that's a real number, and it's the strongest argument for natural gas if you have a service line.

Maintenance is $80 to $300 per visit. A well-maintained standby unit is generally expected to last at least 20 years. Divide the install cost across that lifespan before you decide it's expensive - but do it honestly, including the annual service and the fuel.