Commercial Solar Project Procurement Guide

Production basis

• Compare all proposals using the same site coordinates, weather dataset, array orientation and loss assumptions.
• Separate modeled first-year energy from guarantees and from actual weather variability.
• Document degradation, availability, clipping, soiling and curtailment assumptions.

System scope

• Modules, inverters, racking, electrical balance of system, monitoring, interconnection and commissioning.
• Structural and roof interfaces, fire/access requirements and shutdown equipment where applicable.
• Warranty ownership, service response and replacement assumptions.

Commercial model

• Separate energy value, incentives, tax treatment and financing rather than hiding them inside one payback figure.
• Use scenario ranges for future electricity prices and production, and verify project-specific eligibility with qualified advisers.

Professional references

These references establish the standards, technical framework or authoritative engineering context used for this page. Vendor commercial terms are not used as engineering evidence.

• NREL PVWatts Calculator — NREL reference tool for screening grid-connected photovoltaic energy production.
• BIPM SI Brochure, 9th edition, updated 2026 — Primary international reference for SI units and unit expression.
• NIST Special Publication 811, Guide for the Use of the International System of Units — U.S. NIST guidance for SI use and unit conversions.

Commercial independence

PROFENG may display a separately disclosed approved partner after the engineering content. Partner status never changes formulas, conversion factors, procurement criteria, technical references or calculation results. Pending and unapproved programs remain hidden.