Top-rated generator install pros.

Get matched with top generator install pros in Dennis, MA

Enter your zip and get matched with up to 5 pros

Need a pro for your generator install project in Dennis, MA?

Select your specific project to find the pro for you.

TRUSTED BY DENNIS, MA HOMEOWNERS

  • Average homeowner rating star icon5
    Average homeowner rating
  • Verified reviews icon10
    Verified generator installs reviews

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.

15 neighbors recently requested a quote
Recommended by91%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

266 neighbors recently requested a quote
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 time10 hrs
Response rate89%
13 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

"Tim P, Generator Advisor, visited our house and gave on the spot estimatesâ ¦..he was GREAT. Licensed Electrician who knew his business and was easy to speak with. Timely communications and responses to text messages! Tim was helpful answering questions after the generator was installed. We talked to 5 Generac dealers and a Kohler dealer. Cotti-Johnson had the best pricing in the South Shore area. We highly recommend this company. If you are thinking about buying a standby generator, Cotti Johnson is the company to callâ ¦..Art V"
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%
101 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

58 neighbors recently requested a quote
Recommended by66%of homeowners
Avatar for JP Mechanical Contractors, LLC
JP Mechanical Contractors, LLC
5.0(
3
)
Fixed Generator - InstallPortable Generator - Install

Serving Dennis, MA and surrounding areas

Approved

In business since 2008

Free estimates

Offers commercial services

"Julius was very professional and returned all calls and questions promptly …. We enjoyed meeting him and when he said he was going to follow up on anything we needed, he did… We highly recommend using JP Mechanical Contractors… If the need to use this company again comes up, , we certainly would call Julius… Danka Piekarski"
Response time3 hrs
Recommended by100%of homeowners
Showing 1-10 of 48
Generator Install questions, answered by experts

A portable generator can supply power to selected appliances and circuits in a home, but it's generally not designed to handle the entire household's electrical needs simultaneously. Portable generators have limited wattage capacity, so they are only designed to power essential devices and electronics temporarily until local power is restored. If your power needs outweigh the capabilities of a portable generator, consider installing a whole-home generator instead.

You can determine what size generator you need for a transfer switch by matching the switch to the largest outlet on your generator. Larger generators can power up to 10 circuits, while most 5,000-watt generators can provide power to six circuits. So, if your generator’s largest outlet is 30 amps, you’ll need a 30-amp transfer switch.

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.

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.

In some situations, yes. Never try to put biofuel into any home generator without checking the specifics first. If a generator has the ability to run on diesel, it can also run pure biofuel (the clear kind made from seed oils, for example). But if you are using biofuel made from animal fats or vegetable oils, the generator will need significant modifications before it can handle a sludgier type of biofuel.

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.