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  • Average homeowner rating star icon4.6
    Average homeowner rating
  • Verified reviews icon27
    Verified generator installs reviews

Find Generator install pros in Portsmouth

Diamond Electrical Contractors, LLC

4.83(
76
)
Approved Pro

Diamond Electrical Contractors, LLC

4.83(
76
)
Approved Pro
Customers say: Quick response
Recommended by 94% of Angi customers
Recommended by 94% of HomeAdvisor customers
31 years of experience

We are not currently offering smaller electrical services, including outlets, fixtures, running wire or panels for things that are not in the home like rvs or boats. We only service electrical panel upgrades within the home and the average cost for this service is around 5000$ but cost will go up or vary according to scope of project. At Diamond Electrical Contractors, LLC our training and experience is second to none. For electrical work you can trust, call the professionals at Diamond Electrical Contractors today!

"If you are looking for the Best of the Best hire Mark!! Professional, Quality and Amazing!! Thank you for adding a Circuit Breaker for my Water Tank!!"

Fay S on November 2025

We are not currently offering smaller electrical services, including outlets, fixtures, running wire or panels for things that are not in the home like rvs or boats. We only service electrical panel upgrades within the home and the average cost for this service is around 5000$ but cost will go up or vary according to scope of project. At Diamond Electrical Contractors, LLC our training and experience is second to none. For electrical work you can trust, call the professionals at Diamond Electrical Contractors today!

"If you are looking for the Best of the Best hire Mark!! Professional, Quality and Amazing!! Thank you for adding a Circuit Breaker for my Water Tank!!"

Fay S on November 2025


Avatar for B and H Electric, LLC

B and H Electric, LLC

5.00(
3
)
Approved Pro

B and H Electric, LLC

5.00(
3
)
Approved Pro
Customers say: Quick response
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
2 years of experience

You can depend on us to provide a high quality service at a fair and honest price. We understand that the future of our business depends upon our reputation and that is why customer service is by far our highest priority. If you are looking for a professional you can trust, please call today to schedule a no-obligation estimate!

"Very friendly and took that time to make sure everything was done just right."

Paula M on December 2023

You can depend on us to provide a high quality service at a fair and honest price. We understand that the future of our business depends upon our reputation and that is why customer service is by far our highest priority. If you are looking for a professional you can trust, please call today to schedule a no-obligation estimate!

"Very friendly and took that time to make sure everything was done just right."

Paula M on December 2023


Avatar for Direct Electric, LLC

Direct Electric, LLC

5.00(
2
)
Approved Pro

Direct Electric, LLC

5.00(
2
)
Approved Pro
Customers say: Quick response
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
3 years of experience

Direct Electric LLC is committed to excellence in every aspect of our business. We uphold a standard of integrity bound by fairness, honesty, and personal responsibility. Our distinction is the quality of service we bring to our customers. Accurate knowledge of our trade combined with ability is what makes us true professionals. Above all, we are watchful of our customers' interests, and make their concerns the basis of our business.

"He did an amazing job, everything was really good, everything was on time, pricing was good and I would use them over and over again."

Tyler R on April 2023

Direct Electric LLC is committed to excellence in every aspect of our business. We uphold a standard of integrity bound by fairness, honesty, and personal responsibility. Our distinction is the quality of service we bring to our customers. Accurate knowledge of our trade combined with ability is what makes us true professionals. Above all, we are watchful of our customers' interests, and make their concerns the basis of our business.

"He did an amazing job, everything was really good, everything was on time, pricing was good and I would use them over and over again."

Tyler R on April 2023


"He was very responsive and professional. Everything was done perfectly. "

Rhonda Y on November 2022

With several years of experience, we work hard to bring each customer the best possible service and quality available. We look forward to working with you on your next project. We welcome your questions and thank you for your interest.

"He was very responsive and professional. Everything was done perfectly. "

Rhonda Y on November 2022


Sullivan Electric LLC

5.00(
1
)
Approved Pro

Sullivan Electric LLC

5.00(
1
)
Approved Pro
Customers say: Quick response
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
4 years of experience

Tyler Sullivan is committed to excellence in every aspect of our business. We uphold a standard of integrity bound by fairness, honesty, and personal responsibility. Our distinction is the quality of service we bring to our customers. Accurate knowledge of our trade combined with ability is what makes us true professionals. Above all, we are watchful of our customers' interests, and make their concerns the basis of our business.

"N/A"

Denise X on May 2022

Tyler Sullivan is committed to excellence in every aspect of our business. We uphold a standard of integrity bound by fairness, honesty, and personal responsibility. Our distinction is the quality of service we bring to our customers. Accurate knowledge of our trade combined with ability is what makes us true professionals. Above all, we are watchful of our customers' interests, and make their concerns the basis of our business.

"N/A"

Denise X on May 2022


"Jim provided options for components, timeline and cost for the repair of an older Sonos system. The job was completed expertly and quickly. Highly recommend NH Digital Group for audio visual residential service. I'm a happy customer!"

Kate J on October 2022

We are a locally owned and independent company with over 20 years of experience in home electronics. We understand technology is always changing and wont overcomplicate your solution!

"Jim provided options for components, timeline and cost for the repair of an older Sonos system. The job was completed expertly and quickly. Highly recommend NH Digital Group for audio visual residential service. I'm a happy customer!"

Kate J on October 2022


Matthew Wilson Electric

4.97(
31
)
Approved Pro

Matthew Wilson Electric

4.97(
31
)
Approved Pro
Customers say: Quick response
Recommended by 96% of Angi customers
Recommended by 96% of HomeAdvisor customers
6 years of experience

We pride our company on reliability, great communication, integrity, and quality work. We are experts in our trade and will do our best to keep you as educated as we can on your particular task or project. We look forward to earning your business!

"Matt is the best! My fiancé and I bought an old farm house and it had to be completely rewired. Matt is a super nice guy, was right on point with his estimate and the job was done quickly. I will recommend him to anyone who needs electrical work done. "

Jaime L on September 2025

We pride our company on reliability, great communication, integrity, and quality work. We are experts in our trade and will do our best to keep you as educated as we can on your particular task or project. We look forward to earning your business!

"Matt is the best! My fiancé and I bought an old farm house and it had to be completely rewired. Matt is a super nice guy, was right on point with his estimate and the job was done quickly. I will recommend him to anyone who needs electrical work done. "

Jaime L on September 2025


Avatar for Generator Supercenter of New Hampshire

Generator Supercenter of New Hampshire

5.00(
10
)
Approved Pro

Generator Supercenter of New Hampshire

5.00(
10
)
Approved Pro
Customers say: Quick response
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers
43 local quotes requested

At Generator Supercenter, we are committed to securing your home and peace of mind with back up power solutions. When bad weather hits or an electrical circuit malfunctions, a power outage is likely. When that happens, you can recover quickly if you own a reliable home backup generator. Once your generator is installed, you’ll need reliable technicians available 24/7 and capable of providing quick services. Generator Supercenter of New Hampshire provides experienced technicians for generator installation, repair, and maintenance. Benefits of working with our team: Full-service – Whether you need a new generator, or your current one is malfunctioning, we won’t leave until your generator is up and running as it should be. Convenience – If something goes wrong with your generator, you don’t have to worry about going out to buy a new one or to replace parts. We will come to your home or business and take care of it for you. Free on-site estimate – When you call us, you’re not committed to a service—our estimates are free, so you can meet with a member of our team to learn about your options with no strings attached! Unfortunately we do not do anything with portable generators or any brands not manufactured by Generac. We are also not a parts distributor.

"Matt Sanford and the team at Generator Supercenter were professional, knowledgeable and efficient when surveying my property. They spent quality time educating me on their generator product line and monitoring services. If you're looking for a superior product, company, and team to support you throughout our long New England winters, look no further!"

Chad F on March 2022

At Generator Supercenter, we are committed to securing your home and peace of mind with back up power solutions. When bad weather hits or an electrical circuit malfunctions, a power outage is likely. When that happens, you can recover quickly if you own a reliable home backup generator. Once your generator is installed, you’ll need reliable technicians available 24/7 and capable of providing quick services. Generator Supercenter of New Hampshire provides experienced technicians for generator installation, repair, and maintenance. Benefits of working with our team: Full-service – Whether you need a new generator, or your current one is malfunctioning, we won’t leave until your generator is up and running as it should be. Convenience – If something goes wrong with your generator, you don’t have to worry about going out to buy a new one or to replace parts. We will come to your home or business and take care of it for you. Free on-site estimate – When you call us, you’re not committed to a service—our estimates are free, so you can meet with a member of our team to learn about your options with no strings attached! Unfortunately we do not do anything with portable generators or any brands not manufactured by Generac. We are also not a parts distributor.

"Matt Sanford and the team at Generator Supercenter were professional, knowledgeable and efficient when surveying my property. They spent quality time educating me on their generator product line and monitoring services. If you're looking for a superior product, company, and team to support you throughout our long New England winters, look no further!"

Chad F on March 2022


Avatar for Generator Supercenter of New Hampshire

Generator Supercenter of New Hampshire

4.93(
30
)
Approved Pro

Generator Supercenter of New Hampshire

4.93(
30
)
Approved Pro
Customers say: Quick response
Recommended by 96% of Angi customers
Recommended by 96% of HomeAdvisor customers
81 local quotes requested

Generator Supercenter of New Hampshire is committed to excellence in every aspect of our business. We uphold a standard of integrity bound by fairness, honesty, and personal responsibility. Our distinction is the quality of service we bring to our customers. Accurate knowledge of our trade combined with ability is what makes us true professionals. Above all, we are watchful of our customers' interests and make their concerns the basis of our business. As a father and son-owned business, we’re committed to the best service. When you call us, our estimates are free, so you can meet with a member of our team to learn about your options with no strings attached!

"I want to thank the staff at the Stratham NH location. As a new customer, we got off to a bad start with a scheduling misunderstanding. After my earlier review, I want to acknowledge that they reached out to me to turn a negative experience into a positive one. It's nice to know that this company cares about their customers. I am very happy with the service they performed on my recent Generac generator. The customer service department and the technician were very professional and courteous. I would recommend this company for your generator needs."

Roger C on August 2024

Generator Supercenter of New Hampshire is committed to excellence in every aspect of our business. We uphold a standard of integrity bound by fairness, honesty, and personal responsibility. Our distinction is the quality of service we bring to our customers. Accurate knowledge of our trade combined with ability is what makes us true professionals. Above all, we are watchful of our customers' interests and make their concerns the basis of our business. As a father and son-owned business, we’re committed to the best service. When you call us, our estimates are free, so you can meet with a member of our team to learn about your options with no strings attached!

"I want to thank the staff at the Stratham NH location. As a new customer, we got off to a bad start with a scheduling misunderstanding. After my earlier review, I want to acknowledge that they reached out to me to turn a negative experience into a positive one. It's nice to know that this company cares about their customers. I am very happy with the service they performed on my recent Generac generator. The customer service department and the technician were very professional and courteous. I would recommend this company for your generator needs."

Roger C on August 2024


Granite State Solar creates resilient energy systems for homes and businesses throughout New Hampshire. We meet your energy needs with custom generator, battery backup and solar panel installations.

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Generator Install questions, answered by experts

No, you shouldn’t use an extension cord to plug a generator directly into your home without using a transfer switch. That’s because systems like pumps and HVAC fans need a steady power source that might not be available directly from your generator alone. If you bypass the circuit breaker box, you risk damaging your electrical system, creating a risk of electrical fire or electrical shock to you or any workers repairing lines on your local electrical grid.

Energy output depends on turbine size, average wind speed at your site, and system efficiency. A 5 kW turbine in a good wind location can generate 8,000 to 12,000 kilowatt-hours per year, which may cover a large portion of an average home’s needs. Accurate output estimates require a professional wind assessment and a review of your household’s energy usage patterns.

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. 

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.

You may need a permit for a portable generator if you’ll be installing a transfer switch for your primary residence or similar work. Otherwise, a permit for other uses may not be necessary. Check your local building codes or ask a local generator installer for more information about your local regulations.

The Portsmouth, NH 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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