Standby Generator vs. Portable Generator — What’s the Right Choice?
These are two genuinely different solutions for two different situations. Here’s a straight comparison so you can make an informed decision before calling us.
Standby Generator (Whole-Home or Critical Circuits)
A standby generator is a permanently installed unit, typically natural gas or propane-powered, that sits outside your home on a concrete pad and starts automatically within seconds of a power outage. You don’t have to be home. You don’t have to do anything. The transfer switch detects the outage and the generator takes over.
Standby generators range from 10kW units that power critical circuits to 22kW+ units that can run an entire home including central air conditioning. They require a licensed electrician for the transfer switch wiring and panel connection, a gas line connection from a plumber or gas contractor, and a permit.
This is the right choice for homeowners who want whole-home protection, have a medical device that requires continuous power, run a home office or business from home, or simply don’t want to think about it when a storm hits.
Portable Generator With Transfer Switch
A portable generator gives you flexibility — you can take it with you, lend it out, and store it in the garage between uses. But running a portable generator safely requires a properly wired transfer switch or interlock kit at your main panel. Plugging a generator directly into a wall outlet — what’s called backfeeding — is illegal, dangerous to utility workers, and a serious fire risk.
We wire manual transfer switches and generator interlock kits for portable generators so you can connect power safely, without extension cords running through windows or doors.
This is the right choice for homeowners who want backup power for critical circuits at a lower upfront cost and are comfortable manually starting and fueling the generator during an outage.
The Electrical Work We Handle
Whether you’re going standby or portable, here’s what Larry Berger Electric does on every generator installation:
Load calculation. We calculate your home’s electrical load to size the generator and determine which circuits to back up. Undersized generators are one of the most common installation mistakes — we size it right so you’re not running the generator at 100% capacity under normal outage conditions.
Transfer switch installation. This is the most important part of the electrical work. A properly installed automatic or manual transfer switch is what isolates your home from the utility grid when the generator runs — protecting you, protecting your appliances, and protecting the utility workers restoring power on your street.
Panel connection and circuit selection. For partial-home standby or portable setups, we work with you to identify which circuits matter most — furnace, well pump, refrigerator, medical equipment, select lighting — and wire the transfer switch to back up those specific circuits.
Outlet installation for portable generators. We install a properly rated outdoor generator inlet box so you can connect your portable generator to the transfer switch without running extension cords.
Permit and inspection. All generator electrical work in Nashua requires a permit. We handle it.
What We Don’t Do — and Who Does
We handle all of the electrical work for your generator installation. We don’t install the generator unit itself, pour the concrete pad, or run the gas line — those are separate trades. For a complete standby generator installation you’ll need a generator dealer or installer for the unit and pad, and a licensed plumber or gas contractor for the fuel line.
We’re happy to coordinate with other contractors on your project so the electrical side doesn’t become the bottleneck. If you need a recommendation for a generator dealer in the Nashua area, ask us.
How Much Does Generator Installation Cost in Nashua?
Electrical costs for generator installation depend on the type of generator, the transfer switch configuration, and your panel’s location relative to where the generator will sit.
- Generator interlock kit for portable generator: $300–$600
- Manual transfer switch installation (portable generator): $500–$900
- Automatic transfer switch for standby generator: $1,200–$2,500 for electrical work only
- Full standby generator installation (electrical portion): $1,500–$3,500 depending on complexity
These figures cover the electrical work only, not the generator unit, pad, or gas line. We give you a firm quote for the electrical scope after assessing your panel and installation location.
Call (603) 377-5622 for a free estimate.
Frequently Asked Questions
Do I need a permit to install a generator in Nashua?
Yes. All generator electrical work, transfer switch wiring, panel connections, inlet box installation — requires a permit in Nashua and throughout New Hampshire. We pull the permit and handle the inspection process.
Can I connect a portable generator directly to my house wiring?
No — and this is important. Connecting a generator directly to your home’s wiring without a transfer switch is called backfeeding. It can electrocute utility workers restoring power on your street and can destroy your appliances when grid power returns. A properly installed transfer switch or interlock kit is not optional.
How long does generator transfer switch installation take?
A generator interlock kit or manual transfer switch typically takes four to six hours. An automatic transfer switch for a standby generator may take a full day depending on panel location and complexity.
What size generator do I need for my Nashua home?
It depends on what you want to power. A 7,500-watt portable generator can handle a furnace, refrigerator, and several lights. A 10kW standby unit powers critical circuits comfortably. A 22kW standby unit can run a full home. We do a load calculation during the estimate so you’re not guessing.
Can you install a generator inlet box on the exterior of my home?
Yes. We install weatherproof generator inlet boxes on the exterior of the home rated for the output of your specific generator. This is the proper way to connect a portable generator — not extension cords through a window.
How often should a standby generator be serviced?
Most standby generator manufacturers recommend annual service. The generator dealer or installer typically handles ongoing maintenance — that’s separate from the electrical work we do at installation.
Why Hire Larry Berger Electric for Generator Work
The transfer switch is the most safety-critical piece of a generator installation. Done wrong, it’s a fire hazard and a danger to utility workers. Done right, it’s the thing that makes your backup power reliable and safe every time.
We’ve installed transfer switches and wired generator connections throughout Nashua and southern New Hampshire. We know the permit process, we work cleanly, and we’re not done until the installation passes inspection.
- Licensed NH electrical contractor — License No. [XXXXX]
- All generator electrical work fully permitted and inspected
- Flat quotes after assessment
- No trip fee
- Available for pre-storm installation scheduling
Call or text (603) 377-5622 — or [Request a Free Generator Installation Estimate].
Service Areas
Larry Berger Electric provides generator installation and transfer switch wiring throughout southern New Hampshire including Nashua, Merrimack, Hudson, Milford, Bedford, Amherst, Hollis, and Pelham.