Custom Solar

Custom Solar was founded in 2008 by Willie Mein, a professional engineer who saw an opportunity to bring technical expertise and honest service to Colorado homeowners looking to go solar. What started as a local Boulder solar installer has grown into one of the Front Range’s most respected renewable energy contractors, built almost entirely on word-of-mouth referrals from satisfied customers. Mein, who holds professional engineering licenses in both California and Colorado and previously earned NABCEP certifications in both solar PV and solar thermal installation, leads a team that approaches every project with an engineer’s precision and a neighbor’s integrity. Based in Boulder since day one, Custom Solar serves homeowners and commercial clients throughout Colorado’s Front Range, from Denver to surrounding communities. The company specializes in solar panel installation, battery backup systems, and complete solar energy solutions, handling every step in-house—from engineering and design to permitting, installation, and ongoing maintenance. This integrated approach means clients work with one accountable team from start to finish, not a revolving door of subcontractors. Custom Solar’s licensed professional engineers and NABCEP-certified installers design systems in accordance with industry best practices, and the company’s deep familiarity with local permitting, codes, and Colorado incentives streamlines the process for Boulder homeowners. Over the years, Custom Solar has completed notable projects including a 1.3 MW solar carport at Boulder’s Avalon Ballroom—one of the largest in Boulder County—and a 101-kilowatt system for a recreation center in Alamosa. The company also serves as a SunPower Authorized Dealer and is recognized for its sustainability consultation services. Owner Willie Mein is a board member of the Colorado Solar and Storage Association, reflecting the company’s commitment to advancing solar energy across the state. With a BBB A+ rating and a 4.6-star Google rating from customer reviews, Custom Solar has built its reputation on quality installations, transparent pricing, and customer service that extends well beyond the final inspection. The company’s growth has been organic and steady, adding team members only as the workload demands, ensuring that every installation receives the attention to detail that defines the Custom Solar approach. For Colorado homeowners navigating the solar decision, Custom Solar offers something increasingly rare: local accountability, engineering expertise, and a track record built over nearly two decades of serving the communities where they live and work.