Typical project timeline for commercial solar
A commercial solar project timeline varies by project complexity but commonly spans 3 to 12 months from contract signing to commissioning. Simpler rooftop projects can move faster, while larger ground-mounted sites or projects needing significant permitting, structural work, or utility upgrades may take longer.
Common phases and durations:
- Preliminary design and site assessment: 2–6 weeks
- Engineering, permitting, and interconnection application: 6–16 weeks (can be longer)
- Procurement and equipment lead times: 4–12 weeks depending on components
- Installation and commissioning: 2–8 weeks for typical commercial projects
Factors affecting schedule
- Local permitting and utility interconnection timelines
- Roof repairs, structural upgrades, or electrical panel upgrades
- Equipment lead times, especially for inverters and transformers
- Seasonal weather and access constraints
Early coordination with permitting authorities and the utility, proactive scheduling of roof or electrical work, and working with experienced installers help compress timelines and reduce unexpected delays.