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Find Generator install pros in Dennis

Avatar for Paul Foley Electric Co., Inc.
Paul Foley Electric Co., Inc.
4.7(
79
)
Fixed Generator - InstallFixed Generator - RepairGenerator - Install - For Business+1 more

Serving Dennis, MA and surrounding areas

Approved

In business since 1992

Free estimates

Emergency services offered

At Premier Energy Solutions, your comfort and safety come first. We protect your home or business with turnkey, worry-free generator installations, HVAC systems, and electrical work — all backed by unmatched reliability and value.\n\nEvery project is handled by licensed professionals using top installation practices. From backup power to heating and cooling to electrical upgrades, we make it seamless, professional, and built to last.\n\nSince 1992, Premier Energy Solutions has grown from a licensed electrical contractor into a full-service power, comfort, and safety provider. We deliver a complete, turnkey experience — design, permitting, installation, testing, and support.\nGenerators. HVAC. Electrical. One trusted team.

3 neighbors recently requested a quote
Recommended by91%of homeowners
Avatar for Paul Foley Electric Co., Inc.
Paul Foley Electric Co., Inc.
4.8(
99
)
Fixed Generator - InstallFixed Generator - RepairGenerator - Install - For Business+1 more

Serving Dennis, MA and surrounding areas

Approved

In business since 1992

Free estimates

Emergency services offered

"Great company to work with. Wonderful staff and clear explanations every step of the way. Did everything they said they would do when they said they would do it. Very tidy and no mess despite having to excavate to put in the oil tank for the generator. Installation was done quickly and efficiently. Two years later all working very well and good annual service agreement. Would absolutely work with this company again and recommend them to anyone."
Auto Transfer Switch
Connection to propane tanks
Housekeeping pad
Trenching
Custom Poured Pad

+13

Response time12 hrs
164 neighbors recently requested a quote
Recommended by85%of homeowners
Avatar for Cape Cod Electrical, Inc.
Cape Cod Electrical, Inc.
4.9(
181
)
Fixed Generator - InstallFixed Generator - RepairPortable Generator - Install

Serving Dennis, MA and surrounding areas

Approved

In business since 2015

Free estimates

Emergency services offered

"Cape Cod Electrical installed a stand by generator for me. Vary knowledgeable, always on time, accomplished everything according to the agreement. Pleasure to do business with Cape Cod Electrical. Highly recommended."
Ripped down service wire due to storm damage
After repair
After repair
Existing center light
New recessed lighting with pendent over island

+10

Response time2 days
Recommended by82%of homeowners
Avatar for Champion Electrical Services Inc
Champion Electrical Services Inc
5.0(
54
)
Fixed Generator - InstallFixed Generator - RepairPortable Generator - Repair+2 more

Serving Dennis, MA and surrounding areas

Approved

In business since 2025

Free estimates

Emergency services offered

At Champion Electrical Services, we believe homeowners deserve better. No more no-shows, rushed work, or upsells you don't need. We built this company to do things right - with respect, craftsmanship, and pride. Every project is treated like it's being done in our own home: clean, code-compliant, and built to last. Whether you need a panel upgrade, EV charger, generator, or quick repair, we show up when it counts and earn your trust every time. \nLicensed, insured, and proudly serving MA & RI. \nWhen the lights go out, don't call just anyone. Call the Champ.\n\n(774) 331-3500 \nCalltheChamp.com \[email protected]

My jobs
My jobs
My jobs
My jobs
My jobs

+17

238 neighbors recently requested a quote
Avatar for Cotti-Johnson Heating-Cooling-Electrical
Cotti-Johnson Heating-Cooling-Electrical
4.7(
166
)
Fixed Generator - InstallPortable Generator - InstallGenerator - Install+2 more

Serving Dennis, MA and surrounding areas

Approved (Corporate)

Super Service Award Winner

In business since 1948

Free estimates

Emergency services offered

"Jason and his team with Cotti-Johnson did an excellent job updating our electrical boxes, installing the washer/dryer hookup, and getting us setup with a generator! Sam, our assigned electrician, even took the time to go through the entire operation of the generator from A-Z. I would definitely recommend them for any electrical work!"
Navien Install
Backflow
Outdoor Shower
Well Tank Replacement
Filtration Installation

+62

Response time10 hrs
65 neighbors recently requested a quote
Recommended by89%of homeowners
Avatar for Fagnant Electric
Fagnant Electric
4.9(
56
)
Portable Generator - Install

Serving Dennis, MA and surrounding areas

Approved

Super Service Award Winner

In business since 1985

Free estimates

Small jobs welcome

"I am extremely pleased with Mike's work. Very professional, very responsive, Kept in touch during the bid and installation process. Very reasonable pricing, showed up on schedule and did excellent work. No surprises. I will definitely use his services again and strongly recommend him to others. Business is based in Sandwich, MA."
Bath remodel
Bath remodel
Bath remodel
Bath remodel
Response time11 hrs
Response rate87%
14 neighbors recently requested a quote
Avatar for Cotti Johnson HVAC, Inc.
Cotti Johnson HVAC, Inc.
4.3(
63
)
Fixed Generator - InstallFixed Generator - Repair

Serving Dennis, MA and surrounding areas

Approved

In business since 1944

Free estimates

Emergency services offered

"Expensive but professional. The electrician that did the work was excellent and seemed.to enjoy explaining what he was doing and why it had to be done that way. I felt like I learned something while he installed ceiling lights. He also cleaned up after himself like he'd never been there."
Home Standby Generator Installation
Home Standby Generator Installation
Home Standby Generator Installation
Home Standby Generator Installation
Home Standby Generator Installation

+56

Response time9 hrs
Response rate97%
110 neighbors recently requested a quote
Springer Electric, Inc.
5.0(
3
)
Fixed Generator - Install

Serving Dennis, MA and surrounding areas

Approved

In business since 2009

Free estimates

Credit card accepted

We have over 15 years of experience serving Barnstable county with all of their electrical needs. We take on a wide range of electrical projects to include full installation for additions and remodels as well as generator installs, service change-outs and panel upgrades, and a variety of other jobs. We take pride in our quality of work and our commitment to outstanding results. Our services are customizable based on the specific project needs of each homeowner and business. We look forward to building strong, long-term relationships with all of our clients. Give us a call today to learn about how we can meet all of your electrical needs!\n

Recommended by100%of homeowners
Avatar for Northeast Power, LLC
Northeast Power, LLC
5.0(
3
)
Fixed Generator - InstallFixed Generator - RepairPortable Generator - Repair+3 more

Serving Dennis, MA and surrounding areas

Approved

In business since 2022

Free estimates

Emergency services offered

"My solar inverter stopped working in my existing solar system, and since my original installer went out of business, I had a hard time finding someone to replace the inverter provided by SolarEdge. It was a small job, and most large companies weren’t interested, while those willing to help were booked out for at least a couple of months. I contacted Justin, and he replaced the inverter within just a few days. He was very friendly, efficient, and offered a very reasonable price. Justin was also extremely knowledgeable, explained everything clearly, and kept me updated throughout the process. He arrived on time, completed the work neatly, and made sure the system was running perfectly before leaving. Overall, his professionalism, honesty, and dedication to customer satisfaction made the whole experience stress-free and smooth."
Northeast Power
Northeast Power
Northeast Power
Northeast Power
Northeast Power

+2

47 neighbors recently requested a quote
Recommended by66%of homeowners
Avatar for NAX Electrical Services, LLC
NAX Electrical Services, LLC
4.4(
7
)
Fixed Generator - InstallGenerator - Install - For Business

Serving Dennis, MA and surrounding areas

Approved

In business since 2022

Emergency services offered

Small jobs welcome

"I highly recommend Juan Pimentel for all your electrical needs. I have hired him twice, and he has exceeded my expectations. Juan is very punctual, reliable, courteous and extremely safety conscious. He really knows his business and is a consummate professional. He answers all communications promptly (which I cannot say for many contractors I have hired) plus he goes the extra mile. He even vacuums his work area when he is done! This is the man you want doing your electrical job."
The Lofts
The Lofts
Response time2 hrs
Response rate85%
Recommended by85%of homeowners
Showing 1-10 of 48
Generator Install questions, answered by experts

Generators are safe to use as long as they are installed and operated correctly according to the manufacturer's recommendations. The most critical safety tips are to never use a portable or fuel-powered generator inside an enclosed space due to the risk of lethal carbon monoxide poisoning; always operate it outdoors where fumes can dissipate away from your home. Additionally, never attempt to connect a generator to your home’s electrical panel yourself—hire a professional to ensure the setup meets safety standards. Finally, avoid overloading the generator by not connecting more appliances than it is rated for, as this can damage your equipment or cause a fire.

To determine the right size generator for your house, you should calculate the total wattage of the appliances and devices you want to power during an outage. List all essential items, note their start-up wattages, and add them together.

Here are some typical wattage requirements for common appliances:

  • Refrigerator: 600 watts

  • Large dehumidifier: 700 watts

  • Large window air conditioner: 1,400 watts

  • Water heater: 3,000 to 4,500 watts

  • Electric furnace: 5,000 to 25,000 watts

A 7,500-watt generator might be sufficient for essentials like a refrigerator, freezer, well pump, and lighting circuits. However, for high-demand items like a water heater or furnace, a whole-home generator is a better choice. A portable generator may be enough if you only need to power a few critical items.

While home square footage can offer a rough estimate, it is not always a reliable indicator. For reference, here are some typical generator sizes based on square footage:

  • 1,000 sq ft: 6–9 kW

  • 1,500 sq ft: 7–10 kW

  • 2,000 sq ft: 10–14 kW

  • 2,500 sq ft: 12–16 kW

  • 3,000 sq ft: 16–20 kW+

For the most accurate sizing, consult a professional who can calculate your home's peak and average power consumption and recommend the optimal generator.

You can expect a diesel generator to last for up to 30,000 hours of use, which works out to 20 to 25 years with the proper maintenance, of course. That depends on how much you use it, so a diesel generator used for emergencies a couple of times a year will last a lot longer than a generator that takes over for a faulty electrical grid every month for a day or two. 

Yes, natural gas generators can work without electricity. Natural gas generators are a common type of backup or whole-house generator that operates when the electrical grid isn’t working. The trick is using a transfer switch (which usually needs to be installed with the generator) that safely switches the home electrical system from the power grid to generator power when needed.

Whole-house generators can run continuously for extended periods, even for weeks at a time (around 400 to 500 hours), as long as they have a sufficient fuel supply. However, this type of extensive use will increase wear and tear and can shorten the generator's overall lifespan. During long periods of operation, it's important to check and refill the engine oil as needed, potentially as frequently as daily depending on the model. If your generator uses a fuel tank, ensure it is kept full to prevent unexpected shutdowns.

The Dennis, MA homeowners’ guide to generator installs

From average costs to expert advice, get all the answers you need to get your job done.