As more residential solar installers eye the commercial market, John McDonnell, Managing Partner at WattHub, says the transition demands a completely different playbook.
Speaking at Intersolar & Energy Storage North America (IESNA) Flagship 2026, McDonnell explained that commercial solar starts fresh with every project, shaped by unique site conditions, utility structures, and customer needs—which means installers need more than panels and permits to succeed. He pointed to accurate utility rate analytics, precise customer savings calculations, and access to commercial financing as the pillars of a profitable commercial solar business, and advised residential companies considering the leap to partner with an experienced commercial solar company, or enter a mentorship-style relationship, rather than go it alone.
