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Verified Reviews for Generator Install pros in Annapolis Junction, MD

*The Angi rating for Generator Install companies in Annapolis Junction, MD is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Generator Install needs.

*The HomeAdvisor rating for Generator Install companies in Annapolis Junction, MD is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Generator Install needs.

Last update on June 12, 2026

Find Generator install pros in Annapolis Junction

Avatar for GAC Services
GAC Services
4.8(
292
)

Serving Annapolis Junction, MD and surrounding areas

Approved (Corporate)

In business since 1970

Free estimates

Warranties offered

"The process from beginning to end was highly professional, technically very competent and complete, and the installation was impressive (Team of about nine people, all worked efficiently and simultaneously outside and inside my house. The job was done in a little over half a day. Very happy with my decision to hire GAC to spec, supply, and install the system."
Additional Photos
55 neighbors recently requested a quote
Recommended by94%of homeowners
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Green's Electric
5.0(
16
)

Serving Annapolis Junction, MD and surrounding areas

Approved

Super Service Award Winner

In business since 2007

Free estimates

Emergency services offered

"It went great! Professional, quick to call and discuss the request. What I like the most was their genuine interest in helping me fast. They gave me an estimate the same day and the job was performed in less than 48 hours. I would definitely hire Green Electric for my future requirements. Thanks Mr. Darnell!"
Response time1 day
18 neighbors recently requested a quote
Recommended by80%of homeowners
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Avatar for Bailey & Shipp Electric
Bailey & Shipp Electric
4.1(
82
)

Serving Annapolis Junction, MD and surrounding areas

Approved

In business since 2011

Free estimates

Emergency services offered

"Great company, great people. Talented young team. Very personable. Did a efficient job of getting my generator installed quickest way possible."
3 recessed lights
Single Recessed Light
Custom Bathroom Wiring
chandelier
Panel Replacement After

+8

Response time10 hrs
3 neighbors recently requested a quote
Recommended by91%of homeowners
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Avatar for Clinton Electric Company, Inc.
Clinton Electric Company, Inc.
3.9(
172
)

Serving Annapolis Junction, MD and surrounding areas

Approved

In business since 1969

Emergency services offered

Credit card accepted

"They checked my generator and said nothing was wrong, that the problem was probably with the electric companies transformer. My problem still exist. The electric company sent people out to check the current coming to my house and said everything is okay. They are going to install a monitor to check what is going on when there is an outage. So as of now my generator does not come on."
The Team
Generac Automatic Standby Generator
Dusk to Dawn Spotlights
Electrical Panel
Trucks

+7

Response time2 hrs
135 neighbors recently requested a quote
Recommended by86%of homeowners
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Avatar for One Source, LLC
One Source, LLC
4.8(
6
)

Serving Annapolis Junction, MD and surrounding areas

Approved

In business since 2014

Free estimates

Emergency services offered

One Source Systems is one of the premier custom integrators in the greater Washington D.C. area. We are focused on an elevated client experience and meeting your needs for Smart Home design, including experiential elements such as lighting, shades and incredible dedicated theater and Audio/Video solutions. With over 10 years of experience in the audio industry, we are the experts you need to take care of your home or business. We will treat your home as we would treat our own. Give One Source a call today - we look forward to working with you!

After!
Proper Grounding Showcase
Theater Screen with Starry Night Ceiling
Before!
Lighting Fixtures in a restaurant

+26

Response time2 days
Recommended by80%of homeowners
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Avatar for Serene Elec inst & Rep Services LLC
Serene Elec inst & Rep Services LLC
5.0(
6
)

Serving Annapolis Junction, MD and surrounding areas

Approved

In business since 2015

Free estimates

Emergency services offered

We are committed to excellence in every aspect of our business. \nWe uphold a standard of integrity bound by fairness, honesty and \npersonal responsibility. Our distinction is the quality of service \nwe bring to our customers. Accurate knowledge of our trade combined \nwith ability is what makes us true professionals. Above all, we are \nwatchful of our customers interests, and make their concerns the \nbasis of our business.

Commercial GFCI Repair
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Technician Engineers Group
3.7(
15
)

Serving Annapolis Junction, MD and surrounding areas

Approved

In business since 1996

Offers commercial services

Customers say: Quick response

"Anthony and his team do expert electrical work of all kinds. We are a 145 year old non-profit organization with buildings and grounds, and have contracted with Technician Engineers Group (TEG) on two large projects (and several small ones) over the last 15 years. One project rewired a large 125 year old building listed on the National Register of Historic Places, and one installed an extensive outdoor lighting system. In these two unusual situations TEG worked closely with us to find innovative solutions to our unique needs. We are very pleased with the results, enjoyed their can-do approach, and highly recommend this company for any electrical challenge. We found TEG reliable, honest, on time, and all the work was completed ahead of schedule."
Response time2 hrs
2 neighbors recently requested a quote
Recommended by53%of homeowners
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Showing 1-10 of 118
Generator Install questions, answered by experts

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.

Sizing a generator is a careful process that requires calculating the electrical load of your entire house. You have to take into account every device you want to use and their wattage requirements, plus the wattage needed to start them, and look for a generator that can safely run all that at around 80% capacity.

In more practical terms, a small home can run on a 10,000-watt generator (and if you only want to power a few key appliances, much less than that). A mid-sized home may need something between 15,000 and 22,000 watts. Larger homes require 25,000 watts or more. 

If your home already has a grinder pump and you’re still noticing issues (like frequently clogged toilets and sinks), it could be time to upgrade your grinder pump. Start by checking your existing horsepower. If there are four or fewer people living in your home, using a 1/2-horsepower grinder pump should be sufficient. Larger households should consider investing in a 1-horsepower grinder pump to maximize wastewater removal efforts.

Natural gas generators are designed to run for extended periods of time, such as power outages during a natural disaster. Since there’s no limit to the supply of natural gas, they don’t need to stop for refills. However, generators do need maintenance, including pauses to check and add oil. Constantly running them will also cause a lot more wear and tear, leading to a shorter lifespan.

With proper maintenance, a whole-house generator can last between 20 and 40 years. The specific lifespan depends on how often and for how long the generator is used, and some models may have their life expectancy rated in hours of operation. To maximize its lifespan, expect to spend around $150 to $300 per year for annual maintenance checks from a qualified technician. During these checks, a technician will inspect the engine filter, starting mechanism, fuel, lubrication, and coolant levels. Consulting your installer and choosing a low-impact fuel like natural gas or diesel can also help ensure your generator lasts as long as possible.

The Annapolis Junction, MD homeowners’ guide to generator installs

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

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