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Generator Installation Cost in New Hampshire: 2026 Prices for Standby and Portable Setups

Generator installation cost in New Hampshire for 2026: standby unit pricing by size, propane and transfer switch costs, portable options, permits and installers.

Generator Installation Cost in New Hampshire: 2026 Prices for Standby and Portable Setups

A whole-house standby generator installed in New Hampshire runs $9,000 to $16,000 this year for a typical 18 to 24 kilowatt unit on propane, including the concrete pad, transfer switch, gas line, electrical work, and permits. A smaller 10 to 14 kilowatt unit sized to cover the furnace, well pump, refrigerator, and a few circuits runs $6,500 to $10,500. A manual transfer switch and inlet for a portable generator, the budget option, runs $900 to $2,000.

The ice storm of December 2008 left parts of the state without power for two weeks, and the outages since then have been shorter but more frequent. Wind, wet snow, and the state's tree-lined distribution lines mean most rural homeowners lose power several times a year. This guide breaks down what each generator option costs in New Hampshire, what drives the number, and which choice fits which house.

Standby Generator Costs by Size

The generator itself is roughly half the project. A 10 kilowatt air-cooled unit costs $3,000 to $4,000 at retail, a 22 kilowatt air-cooled unit costs $5,500 to $7,500, and a 30 kilowatt liquid-cooled unit for a large home starts around $12,000 before installation. Most New Hampshire homes between 1,800 and 3,000 square feet land on an 18 to 24 kilowatt unit.

Installation adds $4,000 to $8,000 on a standard job. That covers the automatic transfer switch, the pad, the wiring from the generator to the panel, the fuel connection, the permit, and the startup. Complicated jobs with long trenching runs, a panel upgrade, or a load management system push past $10,000 in labor and materials.

Sizing depends on what you want to run, and a well pump, a boiler or furnace, the fridge, and lights can run on 10 to 14 kilowatts. Add central air, an electric range, an electric water heater, or a heat pump and you are in the 20 to 26 kilowatt range. Homes in Bedford, Hollis, and Windham with 4,000 square feet and multiple HVAC zones sometimes need 30 kilowatts or more.

Load management modules are a middle path. They let a smaller generator power a larger house by shedding lower-priority circuits when the load gets high, and they add $400 to $900 to the install. On a house where a 22 kilowatt unit would otherwise need to be a 30, they save money.

Fuel: Propane Dominates in New Hampshire

Natural gas is available in parts of Manchester, Nashua, Concord, Portsmouth, and the Seacoast, and a natural gas generator is the simplest to fuel since it never runs dry. Most of the state does not have gas service, so propane is the standard fuel for standby units from the Lakes Region north and across the western counties.

A propane installation needs a tank sized to the generator's run time, and a 22 kilowatt unit burns roughly 3 to 4 gallons per hour at full load, so a 500-gallon tank gives you four to five days of continuous power. Tank installation, if you do not already have one, runs $2,000 to $4,000 for a buried 500-gallon tank and $1,000 to $2,000 for an above-ground tank. Many propane suppliers lease tanks for a smaller upfront fee.

The gas line from the tank to the generator runs $15 to $30 per linear foot for trenching and pipe. A generator placed 60 feet from the tank adds $900 to $1,800 for that run alone. Placing the generator near the tank and near the electrical panel is the single biggest way to control installation cost.

Diesel generators are rare on New Hampshire homes and mostly appear on large properties or farms. They cost more upfront and require fuel that degrades in storage.

Cold Weather Kits and Winter Reliability

New Hampshire winters require a cold weather kit, which includes a battery warmer and an oil heater so the unit starts at 10 below zero. It adds $200 to $400 and should be on every quote. A generator that fails to start in January because nobody added the kit is a common service call.

Snow load matters as well. The generator needs clearance on all sides and a location where roof snow will not slide onto it. Installers in the North Country and the Lakes Region often build a small roof over the unit or place it under an eave with a snow guard above.

Transfer Switch Options

An automatic transfer switch senses the outage, starts the generator, and switches the house over within about ten seconds. It costs $800 to $2,000 installed depending on amperage and whether it covers the whole panel or a subpanel of selected circuits. Whole-panel switches at 200 amps are standard on newer homes.

Smart transfer switches with load management and a phone app add $300 to $800. They let you see fuel level, run hours, and maintenance alerts remotely, which is useful for seasonal homes in Conway or Meredith.

Portable Generators and Manual Transfer Switches

A portable generator with a manual transfer switch is what many New Hampshire homeowners use, and it works. A 7,500 to 9,500 watt portable unit costs $1,000 to $2,000, and an electrician installs an outdoor inlet box and a manual transfer switch or interlock kit for $900 to $2,000. Total cost lands between $2,000 and $4,000.

The tradeoff is that someone has to be home to wheel the generator out, plug it in, start it, and flip the switch. During a February outage at 2 in the morning, that matters. Fuel is also a chore, since a portable unit on gasoline burns through a five-gallon can every 8 to 12 hours and gasoline goes stale.

Dual-fuel portables that run on propane solve the storage problem, and tri-fuel units that can also use natural gas are now common. An interlock kit, which mechanically prevents the main breaker and the generator breaker from being on at the same time, is the cheapest legal way to connect a portable, at $300 to $700 installed.

Never backfeed a house through a dryer outlet. It is illegal in New Hampshire, it can kill a lineworker, and it will void your homeowners insurance.

Permits, Code, and Electrician Licensing

New Hampshire requires a licensed electrician for any generator connection to the house panel, and most towns require both an electrical permit and a building or mechanical permit for a standby unit. Permit fees run $75 to $300 depending on the town. Propane work must be done by a licensed gas fitter, and many generator installers carry both licenses or subcontract the gas side.

The National Electrical Code requires the generator to sit at least 5 feet from any window, door, or vent, and 18 inches from the house wall. Manufacturers often require more. Towns like Amherst, Exeter, and Hanover have setback rules for accessory equipment, and a generator too close to a lot line can trigger a zoning issue.

Homeowners should get the permit number and final inspection sign-off in writing. An unpermitted generator becomes a problem at resale and in an insurance claim. For more on hiring licensed trades in the state, browse the New Hampshire home services blog.

Maintenance Costs After Installation

Standby generators need an annual service that runs $200 to $400 in New Hampshire, covering an oil change, filter, spark plugs, and a load test. Many installers sell a service plan for $300 to $500 per year that includes the visit and priority response during an outage. Batteries last three to five years and cost $100 to $200 to replace.

The unit will run a self-test weekly for about 10 minutes, which uses a small amount of fuel. Owners of seasonal homes should schedule a service visit before the property sits empty for the winter.

Utility Programs and Tax Considerations

Eversource, Unitil, and Liberty Utilities do not offer generator rebates, and the state has no incentive program for standby units. Some homeowners pair a generator with a battery system, and the battery portion may qualify for federal tax credits. A standby generator alone does not.

Choosing an Installer

Get three quotes from companies that install the brand they sell and service it afterward. Many electricians in New Hampshire are authorized dealers for one or two manufacturers, and dealer status matters because warranty work must go through an authorized servicer. A generator installed by a general electrician with no dealer relationship may leave you searching for someone to honor the warranty.

Ask how many units the company installed last year and whether they handle the gas line themselves. Ask what the lead time is, because in the fall, after the first outage of the season, lead times stretch to eight or ten weeks as everyone calls at once.

Spring and summer installs are faster and sometimes cheaper. Licensed electricians who handle generator work are listed in our directory of New Hampshire electricians.

A complete quote lists the generator model, the transfer switch model, the pad, the fuel line footage, the cold weather kit, permits, and the warranty terms. Anything missing from that list is a question to ask before signing.

Frequently Asked Questions

How much does a whole-house generator cost in New Hampshire?

A fully installed 18 to 24 kilowatt standby generator runs $9,000 to $16,000 in most of the state, including the transfer switch, pad, gas connection, and permits. Adding a new propane tank can add $2,000 to $4,000.

What size generator do I need for a New Hampshire home?

A house with a well pump, oil or propane heat, and standard appliances can run on 10 to 14 kilowatts. Add central air, an electric range, or a heat pump and you need 20 kilowatts or more. An installer will do a load calculation based on your panel.

Do I need a permit to install a generator in New Hampshire?

Yes. Every town requires an electrical permit for the transfer switch connection, and most require a building or mechanical permit for the standby unit and gas line. A licensed electrician and a licensed gas fitter must do the work.

How long will a propane generator run on a 500-gallon tank?

A 22 kilowatt generator at moderate load burns 2 to 3 gallons per hour, giving a 500-gallon tank, which is filled to 400 gallons, roughly five to seven days of continuous operation. Running only the circuits you need stretches that further.

Is a portable generator with a transfer switch a good alternative?

For many homes, yes. A 9,000 watt portable with a manual transfer switch costs $2,000 to $4,000 total and covers a furnace, well pump, and refrigerator. The limits are that you have to be home to start it and you have to keep fuel on hand.