Give every bidder the same project record and scope checklist
A comparable commercial quote starts with comparable information. Provide the address, building use, roof objective, existing array records, and operating constraints. A service partner can identify what still needs inspection, but missing system data should be visible in the scope rather than hidden as an assumption.
Ask vendors to describe the full path from an operating system to an accepted, operating system. The lowest removal line item can omit storage, roof handoff, replacement components, return-to-service paperwork, or a second mobilization if the roof schedule moves.
| Work category | Items to define in the proposal |
|---|---|
| Survey and preparation | Existing faults, inventory, available drawings, monitoring access, required design review |
| Shutdown and removal | Electrical scope, module and racking removal, access equipment, work zones, isolation sequence |
| Transport and storage | Handling responsibility, secure location, weather protection, duration, custody and extra charges |
| Roof coordination | Roof-ready handoff, attachment treatment, waterproofing responsibility, warranty conditions |
| Reinstallation | Approved mounting design, replacement components, wiring, layout changes, testing |
| Closeout | Permits, inspections, utility records, monitoring verification, acceptance criteria, final documents |
- Define how change orders are priced if modules, wiring, racking, roof conditions, or attachments cannot be reused. Name the party authorized to approve additional spending before work starts.
Coordinate roof warranty obligations, attachments, and equipment custody
Obtain roof manufacturer requirements before choosing the final attachment and waterproofing approach. NREL’s operation-and-maintenance guide discusses overburden waivers, roof-warranty coordination, pre-work roof review, final roof inspection, and the need to keep solar work compatible with the roof system. Its planning principles are useful, but the responsible roofer, manufacturer, and contractors decide the actual details.
Define the roof-ready handoff in writing. The roofer and solar contractor should agree on the evidence that allows reinstallation to begin, who resolves an attachment or waterproofing concern, and how a changed roof assembly affects the original array configuration.
Before removal, create an inventory with equipment models, serial numbers where available, module counts, photographs, and intended storage location. Repeat the record at storage receipt and reinstallation. The owner should know who has custody of each component and what happens if a part is damaged or cannot be reused.
Model production downtime before choosing a construction schedule
Estimate downtime from expected production during the actual work period and the value of that energy under the property’s utility and contractual arrangements. Historical monitoring for comparable dates is a starting point; weather, seasonal variation, demand charges, exported energy, PPA terms, and tenant allocation can change the result.
FPL explains that most business meters record the highest 30-minute level of demand in each billing period. A simple lost-kilowatt-hour calculation therefore does not substitute for a tariff, interval-data, or contract analysis on a demand-billed property.
Hypothetical arithmetic only; not a customer result, energy-price quote, production forecast, or savings guarantee.
| Assumed outage period | Lost production | Calculated energy value |
|---|---|---|
| 20 days | 14,400 kWh | $2,016 |
| 30 days | 21,600 kWh | $3,024 |
| Additional 10-day delay | 7,200 kWh | $1,008 |
- Assumptions: 720 kWh per day, $0.14 per kWh, and energy that would have offset purchases at that value. Lost energy equals expected daily production multiplied by days offline.
Confirm phasing, safety controls, permits, and utility requirements
Whether one roof section can stay online while another is reroofed depends on the electrical design and approved work plan. Ask for a written phasing explanation that identifies which equipment remains active, how workers are protected, what production is assumed, and how many mobilizations or roof handoffs are required.
OSHA identifies electrical and fall hazards in solar work. Contractors—not this guide—must establish site controls, lifting methods, work boundaries, shutdown procedures, fall protection, and emergency response for the property.
For FPL-served sites, FPL’s current guidelines publish gross-AC tiers based on DC array capacity multiplied by 0.85: Tier 1 up to 10 kW, Tier 2 above 10 through 100 kW, and Tier 3 above 100 through 2,000 kW. The same guidance lists different requirements for higher tiers and requires confirmation before installation or normal operation. Other utilities and municipal providers have their own requirements.
- Identify the serving utility and applicable city or county permitting authority by the property address.
- Ask the responsible contractor whether unchanged reinstallation, substituted equipment, expansion, or changed electrical configuration has a different approval path.
- Include permit, inspection, interconnection, meter, disconnect, insurance, and return-to-service dependencies in the project schedule when applicable.
Define what the owner receives before accepting the project
Agree on acceptance criteria before signing the scope. The completed package should let the owner identify what returned to service, what changed, which approvals were completed, and where to find future-service records.
Review performance under suitable conditions after the system resumes operation. Ask the contractor to explain how expected and observed production are compared, while accounting for weather and seasonal variation. Keep the roof and solar records together for future service, refinancing, sale, or another reroof.
- Final equipment inventory, replacements, photographs, and updated drawings or layout records where changes occurred.
- Electrical test results appropriate to the installed equipment and completed inspection or utility records that apply to the project.
- Monitoring confirmation, authorized-owner access, a dated production baseline, and identified punch-list items.
- Roof acceptance documentation, applicable warranty records, and named service contacts for the owner’s file.