603 Solar

603 Solar designs and installs residential and commercial solar out of Exeter, and its New Hampshire electrician licence 0594C is verified active in the state registry under the company's own name. Its Google profile is 5 stars from 170 ratings, and the Better Business Bureau accredits it at A+. The reviews are unusually consistent about what the company sells: an explanation first. Customers describe long site visits, production estimates laid out in plain numbers, and advice against upgrades that would not pay back. In a February 2026 review, a customer with a difficult roofline said the advisor steered them to the largest workable array — 16 panels — and was transparent about the trade-offs. In a 2026 review, another customer was walked through owning versus leasing with no pressure, and a 2023 customer described an 8 kW system of twenty 400-watt panels designed after a detailed proposal. Installation is fast once it starts. An October 2025 customer had 20 panels fitted in a single day, earlier than scheduled, through to the utility switch-on; a May 2026 customer described crews working through drizzle across multiple roof lines and materials to hold the schedule, leaving no debris behind. The electrical work is done by a subcontractor, Grateful Electric, which customers name and praise as often as they do 603's own staff. Production results show up too, which is rare in solar reviews. A July 2025 customer reported a first full monthly bill from Unitil that came back as a $43.24 credit and expected roughly $2,200 a year in savings; an April 2026 customer whose panels had been running over two years said the first year beat the projected production. A May 2026 customer whose original installer went out of business had 603 Solar service the orphaned system and get it running again. Two cautions are worth carrying into the conversation, both from a solar forum rather than a customer. In a July 2024 Reddit thread, a commenter called the company reputable with accurate estimates but flagged that it subcontracts all the installation work and has not been in business long. The written record here begins in 2021, and the mention of subcontracting matches what customers describe — a division of labor they seem happy with, but one to confirm in writing. For a residential array where you want the design reasoning explained and someone to handle permitting and the utility interconnection, this is a deep, uniformly positive record. Ask who holds the workmanship warranty — 603 or the electrical subcontractor — and how service calls are handled after the system is live.