How Commercial Rooftop Solar Works

A commercial rooftop solar installation converts available roof space into a power plant that offsets your purchased electricity from the grid. For most commercial facilities, a properly sized rooftop array can offset 15-80% of total annual electricity consumption, depending on roof area, local solar irradiance, and facility load profile.

The process begins with an energy audit and roof assessment. Our EPC partners analyze your utility bills, roof structure, orientation, and shading conditions to design a system optimized for your specific location and rate structure. Unlike residential solar, commercial installations require full structural engineering analysis, often with stamped drawings from a licensed PE, as well as HVAC and electrical coordination with your facility team.

What's Included in Our Commercial Rooftop Service

  • Energy Audit and Production Modeling: PVsyst or equivalent simulation of annual production, matched to your specific utility rate structure and monthly load profile
  • Structural Engineering: Roof load analysis, racking system design, and stamped PE drawings for permit submission
  • Permit Management: Building, electrical, and fire permits managed by our EPC partner across every jurisdiction we serve
  • Utility Interconnection: Full application and coordination with your utility, from Level 1 simple connect to Level 2 and Level 3 studies for larger systems
  • Equipment Procurement: FEOC-compliant panels, inverters, and racking sourced for domestic content ITC adder eligibility where possible
  • Installation and Commissioning: Professional installation by certified solar installers, followed by utility inspection and Permission to Operate
  • 25-Year Warranty Package: Panel production warranty, inverter warranty, and workmanship warranty through the installing EPC

Rooftop Solar by Property Type

Commercial rooftop solar economics vary significantly by property type. Manufacturing facilities and distribution warehouses typically offer the strongest ROI because of their combination of large flat roof areas, high daytime electricity consumption, and significant federal tax liability to leverage. These factors align perfectly with our zero cap-ex ESP financing model.

Office buildings, retail properties, multifamily apartment complexes, hotels, and institutional buildings all represent strong rooftop solar candidates as well. The key variables are roof area available (minimum ~5,000 sq ft for a meaningful system), annual electricity spend (minimum ~$50,000/year for strong ESP model economics), and federal tax liability (for the zero upfront financing path).

Frequently Asked Questions

How much roof space is needed for commercial solar?
A rough rule of thumb is 100 sq ft of roof space per kW of solar capacity. A 100 kW system requires approximately 10,000 sq ft of usable roof area. However, actual system size depends on roof orientation, tilt, shading, and local solar irradiance. Our EPC partners use satellite imagery and roof assessment tools to determine actual usable area before designing a system.
What types of commercial roofs are compatible with solar?
TPO, EPDM, modified bitumen, metal standing seam, and concrete/tile roofs are all compatible with commercial solar. Flat TPO and EPDM roofs are the most common and typically use ballasted or mechanically attached racking systems. Metal standing seam roofs use non-penetrating clamp systems. Our EPC partners assess roof age and condition as part of the site evaluation, and recommend roof repairs or replacement timing if needed before solar installation.
How long does a commercial rooftop solar project take from start to finish?
Typical commercial rooftop projects take 5-9 months from signed contract to Permission to Operate. The timeline includes system design (4-6 weeks), permitting (30-90 days depending on jurisdiction), utility interconnection approval (60-150 days depending on system size), and physical installation (2-6 weeks). Our EPC partners manage all timelines and communicate regularly with your team throughout.
Does rooftop solar void our commercial roof warranty?
It depends on your roof warranty terms and installation method. Many commercial roof warranties can be maintained with proper installation by a certified roofer working alongside the solar EPC. Some roofing manufacturers have approved solar racking systems that maintain warranty coverage. Our EPC partners coordinate with your roofing contractor and warranty holder as part of the installation planning process.