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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
)

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.

9 neighbors recently requested a quote
Recommended by91%of homeowners
Avatar for Champion Electrical Services Inc
Champion Electrical Services Inc
5.0(
54
)

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

254 neighbors recently requested a quote
Avatar for Fagnant Electric
Fagnant Electric
4.9(
56
)

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
)

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
)

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
)

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

57 neighbors recently requested a quote
Recommended by66%of homeowners
Avatar for JP Mechanical Contractors, LLC
JP Mechanical Contractors, LLC
5.0(
3
)

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

To power a central air system during a power outage, the whole-house generator will need to be at least 5,000 watts, and this number will significantly increase for larger units. Check the specific wattage requirements of your AC unit to choose the right generator size. Consider consulting a generator installer to ensure your whole-house generator meets your electrical load needs.

If you have a transfer switch properly installed, the generator and main electrical power cannot feed the system at the same time. However, you should still shut off the power at your main circuit breaker panel before activating the generator. If you do that, you’ll simply need to shut off the generator and reset your circuit breaker once the local power comes back on.

A 1,500 square foot home will likely need a 15kW to 20kW generator. When deciding on whole-house generator size, add up the total wattage of the devices that you’d like to continue running during a power outage. That way, you can ensure you purchase a generator that can power your necessary appliances or medical equipment during an electrical emergency.

Whole-house generators need to be installed on level ground several feet away from walls and other objects. Because they tap into the electrical system directly, they usually need to be close to your home electrical panel for a transfer switch installation. It also helps with installation if they are near to a gas line or propane tank installation.

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.

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.