603 Solar has grown into one of New Hampshire's most consistently recognized residential solar specialists since co-founders Zachary Haithcock and Sean Carlson launched the company in 2018. Headquartered at 24 Charter Street in Exeter, the firm has helped more than 1,200 home and business owners install systems that have collectively produced over 20 million kilowatt-hours of clean energy, and its service territory now reaches across New Hampshire, southern Maine, and northern Massachusetts from a single in-state base of operations.
What stood out to our research team is how the company stacks credentials against the market it serves. 603 Solar holds NABCEP certification, has been BBB-accredited with an A-plus rating since 2019, and is a member of Clean Energy NH, the Northeast Sustainable Energy Association, and Sustainable Seacoast. The company is an EnergySage-approved supplier and has won first place in the 'Best of the 603' Magazine awards in 2023, 2024, and 2025, alongside repeated wins in the Best of the Seacoast Community Choice Awards. That kind of sustained local recognition is difficult to manufacture and reflects a track record that customers in Rochester, Portsmouth, Manchester, Concord, Dover, and Exeter have validated repeatedly.
The numbers behind 603 Solar's customer satisfaction are unusually strong for a company at this scale. The Birdeye platform aggregates 177 reviews at a perfect 5-star average, the Google profile shows a 5.0 rating across 160 reviews, and SolarReviews customers describe the team as 'extremely knowledgeable, transparent, and prompt.' Founders Haithcock and Carlson each bring nearly a decade of solar industry experience predating 603 Solar's founding, and the company performs site evaluation, system design, permitting coordination, and installation in-house rather than relying on subcontractors. They also work with multiple inverter brands, which gives homeowners flexibility on equipment.
As a New Hampshire-rooted installer that has built its reputation entirely within the state and its immediate border markets, 603 Solar brings firsthand familiarity with Eversource and Unitil interconnection workflows, New Hampshire's net-metering rules, and the specific permitting expectations of Rockingham, Strafford, and Hillsborough County jurisdictions.
With a composite score of 82.1 out of 100, 603 Solar stands as our top-ranked solar company in New Hampshire for 2026.
“603 Solar did an amazing job installing a solar array on my garage roof and backside of my business this past month. From start to finish the project went smoothly, with clear and regular...”
Phil B.
“603 was absolutely wonderful to work with for the solar install! From the estimate right on through the project, they had great communication, they did clean work, and made sure it was hassle free. I...”
Margaret H.
“603 Solar installed 20 panels on our roof last month. Everything went like clockwork, from the first meeting with Steve to the final "flip of the switch" to connect us with Eversource. The...”
Jon L.
“Quite simply the BEST contractor I've ever worked with. Communication, Service, Installation and follow-up are impeccable! Will 100% do business with them anytime I need solar work done.
We were...”
George C.
“I highly recommend 603 Solar to anyone considering investing in residential solar generation. I requested and received quotes from 4 companies and 603 Solar was the most responsive to my questions...”
gary d.
“Very professional easy to work with. Geat communication
Nice quality installation.
I would recommend them to family and friends”
Joe D.
“I had been researching different solar options for several years and decided to hire 603 Solar for the system design and installation at our house in Madison, NH. Steve came out to the house and...”
James G.
“We had Joey from 603 Solar come out in Oct to go over the details and give us a quote. Their pricing was competive in comparison with other solar installers plus I liked the fact that they were...”
ReVision Energy is one of the most established and mission-driven solar companies operating in New England, with 20 years of experience and a Brentwood, New Hampshire headquarters that anchors their operations across the state. The company is structured as an employee-owned cooperative and holds B Corporation certification, a designation that reflects a verified commitment to social and environmental performance standards that go beyond the typical solar installer's marketing claims.
The scale of ReVision Energy's operation sets them apart from most regional competitors. With more than 400 employee-owners spread across offices in Maine, New Hampshire, Massachusetts, and Vermont, they have the infrastructure to handle projects ranging from modest residential rooftop systems to large commercial and institutional installations. Their Brentwood facility includes a showroom, design offices, and a 7,000-square-foot warehouse that supports their installation teams. Solar Power World has ranked ReVision as the number one rooftop solar installer in New England for five consecutive years, a distinction that reflects both volume and consistency.
Their NABCEP-certified installation crews work across solar electric, solar heat pump, and EV charger installations, giving homeowners access to a broader energy transition toolkit than most single-service solar firms can offer. The company's 4.8-star Google rating across 194 reviews demonstrates solid customer satisfaction, with particular praise for system design quality, project management communication, and post-installation support.
The employee-ownership structure is worth noting because it tends to produce different incentive alignment than privately held or venture-backed solar companies. When the installation crew and the design team have a direct financial stake in long-term customer satisfaction and company reputation, the pressure to cut corners or oversell system capacity is meaningfully reduced. That structural advantage does not guarantee a perfect experience for every customer, but it creates a framework where quality tends to be prioritized over speed.
ReVision Energy earns a composite score of 73.1 out of 100, securing the number two ranking among New Hampshire solar installers for 2026.
“We had 23 panels, a whole house battery, and associated equipment installed in December. The entire process was quite well managed. Communication throughout was great, and the team just handles...”
J H.
“Revision just finished a sizable installation at my home. It included a 30-panel Solar Electric System, a Battery Storage System with two Tesla Powerwall 3's and a Heat Pump System with one 9,000 BTU...”
Taryn F.
“Super impressed - the installation is "clean" meaning no visible wires, positioning on roof is perfect, etc. The team was exceptionally knowledgeable, courteous, and professional. Despite heavy rain,...”
Karen B.
“We had a great experience with Revision! We appreciated the professionalism of everyone we met. We appreciated their promptness in scheduling and paperwork. We were thrilled to have solar installed...”
Dave K.
“ReVision Energy - Nice company to work with, from the salesman, the design and permit dept, the installation scheduler to the installation crew very professional team. ReVision Energy installed a...”
Emily B.
“We loved working with ReVision Energy. They installed an 18-panel solar display on the roof of our house, and it looks great. They also installed a heat pump in our living room. (The heat pump was...”
Nic P.
“The decision to go solar was easy, who to choose and trust with the project... not so easy.. We met with a few companies to get an overall understanding of what was needed and the process, and of...”
Ahmaul Y.
“ReVision Energy was highly recommended by a family friend. They were cost competitive with other solar companies, did their best to accommodate my requests and did an excellent job on the install....”
Granite State Solar has been a dedicated New Hampshire installer for 18 years, operating from their base in Bow to serve homeowners across the Granite State. In a market where national chains and out-of-state companies periodically enter and exit, the company's nearly two-decade commitment to a single state gives them an intimate familiarity with New Hampshire's permitting landscape, utility interconnection requirements, and the specific incentive programs that make solar economics work for local homeowners.
The company has earned consistent recognition within the state, including being voted Best of Business for solar for close to a decade and winning the Best of the 603 award every year the competition has been held from 2021 through 2024. These are community-driven honors rather than pay-to-play industry awards, which makes them a more reliable signal of genuine local reputation. Their 4.8-star Google rating across 223 reviews reinforces that picture, with customers regularly citing professionalism, system design quality, and a smooth installation experience from initial quote through final commissioning.
Granite State Solar focuses on both residential solar panel systems and backup power solutions, a combination that has become increasingly relevant as New Hampshire homeowners seek resilience against winter storms and occasional grid instability. Their installation teams handle the full project lifecycle in-house, from site assessment and design through permitting, installation, and utility interconnection, avoiding the subcontractor handoffs that can introduce quality control gaps.
Some customer feedback has flagged occasional delays in post-installation service visits, a pattern that is not uncommon among successful regional installers whose growth sometimes outpaces their service department staffing. For homeowners considering Granite State Solar, it is worth asking about current service response timelines during the sales process. That caveat aside, the company's track record of repeat business and community recognition speaks to a level of operational consistency that is difficult to manufacture.
Granite State Solar earns a composite score of 73.1 out of 100, placing them at number three among New Hampshire solar installers for 2026.
“We recently hired Granite State Solar to install solar panels in our home. The entire process, from proposal, to installation, to follow-up summary was excellent. Our contact, Andrew, was very...”
Pete F.
“Granite State Solar did everything they said they would in our preliminary meeting. They expedited all the permits and kept us informed every step of the way. They finished on the schedule we agreed...”
Larry Y.
“From beginning to installation completion GSS was great to deal with. I was a little leery of having panels installed, not because I didn't want them, but because I had doubts the panels would ever...”
Donna G.
“Granite State Solar has been awesome to do business with. From the first phone call they were very responsive and informative about their solar program and generators as well. They performed the...”
Greg B.
“We've been interested in solar since moving in last April, having enjoyed the benefits at our previous home. Granite State Solar sent Thomas to evaluate our property, and he provided three excellent...”
Jeff C.
“I am very happy with the install of my solar panels and battery backup system that GSS installed. From the initial consultation, to the install process, and the final post install review, they did an...”
Raphael M.
“Fantastic experience! I interviewed four companies in the summer of 2025. The goal: to install a 10 panel solar array on my garage before Jan 2026, to chase expiring tax credits. Two companies...”
Joseph A.
“After 3 years we are very pleased with the performance and simplicity of our solar array. The design is sufficient to more than meets our electricity and heating needs, with enough extra to power our...”
Property tax exemption for solar systems|Net metering at retail rate|No state solar tax credit|NH Electric Co-op solar programs|Renewable energy rebate programs
NH law limits the amount of customer owned generation used for net metering for each utility's service area. If you are interested in net metering, make sure to ...
If you are installing distributed generation (e.g., solar panels), or already have a renewable generator, you may be eligible for net metering, a billing method ...
This law (RSA 362-A:9, XIV) permits net-metered renewable energy facilities, known as hosts, to share the proceeds from surplus electricity generation with ...
The current rules apply to all solar installations under 1,000 kilowatts (kW), and the owners of those systems will receive bill credits under net metering ...
New Hampshire's Department of Energy has requested a $70 million federal grant to expand community solar programs for low-income residents, an infusion of funds ...
Learn about New Hampshire solar incentives in 2025 and how federal tax credits, net metering, and property tax exemptions can lower solar costs for homes ...
The state of New Hampshire has ~2500 hours of sunshine and 90 clear days per year. In comparison, Nevada has about 160 clear days annually and about 3600 hours ...
*Companies displaying 15 or more years in business are typically established electrical, roofing, or general contracting firms that expanded into solar installation in more recent years. The years shown may reflect the age of the parent organization or a strategic partner, not necessarily the solar division itself. This distinction is worth considering when comparing to dedicated solar installers, as purpose-built solar companies may offer more specialized expertise despite a shorter operating history.
