SRCC certification is the primary quality benchmark for solar thermal products in the North American market: the Solar Rating & Certification Corporation independently tests and certifies solar water heating equipment against strict performance, durability and safety standards. Two programs do most of the work — OG-100 for individual solar collectors and OG-300 for complete solar water heating systems.
What is the SRCC and why does it matter?
Established in 1980 and now operating as part of the International Code Council (ICC), the SRCC develops standards and testing procedures for solar water heaters, collectors and systems, and publishes verified performance data that consumers and professionals can act on. Certification is frequently a requirement for government incentive programs and regulatory approvals, and many jurisdictions and utilities require SRCC-certified systems before granting permits or rebates.
OG-100 vs OG-300: which program covers what?
| Program | What it certifies | Testing basis | Who relies on it | |---------|-------------------|---------------|------------------| | OG-100 | Individual solar collectors | ICC 901/SRCC 100 (based on ISO 9806) | Manufacturers and specifiers comparing collector performance | | OG-300 | Complete solar water heating systems | System-level performance and safety evaluation | Installers, code officials and incentive programs |
How does the certification process work?
It starts with a comprehensive application: detailed product specifications, design documentation and material descriptions. Independent laboratories authorized by the SRCC then test sample units for thermal performance, structural integrity, durability under varied environmental conditions, and safety — including freeze and pressure resistance. Crucially, the SRCC verifies that the manufacturer's performance claims match the actual test results.
Before certification is granted, manufacturers must also supply clear user manuals, installation instructions and warranties. Certified products then carry a unique SRCC label — and certification continues with periodic audits and random product sampling to confirm sustained performance.
How do you read an SRCC rating?
Each SRCC label carries the model number, certified thermal performance, climate zone suitability and output values under different conditions. The headline figures for comparison are the OG-100 standard daily production ratings, given in kWh (thermal) or thousands of Btu per panel per day for standard climate and temperature categories, which let you compare models directly on energy contribution potential.
Two practical tips. First, check climate-specific data: collector efficiency varies with sunlight availability and ambient temperature, so a rating that suits one region may mislead in a colder one — select systems rated for the local climate. Second, verify that a product's rating meets the minimum certification requirements of whatever incentive or rebate program applies, since many programs specify thresholds. Professionals can also filter the SRCC database by rating, certification, manufacturer and technical specification to streamline procurement and system design.
How does SRCC compare with European certification?
For European markets, the counterpart mark is Solar Keymark — and the two schemes share a technical backbone, since both build on ISO 9806 collector testing. For a manufacturer serving global markets, that overlap is good news: the same disciplined testing culture supports both certificates, whether the product is a flat-plate collector or a PVT hybrid. What changes is the program structure — SRCC's OG-100/OG-300 split and its links to US incentives and building codes have no exact European equivalent, so market-by-market compliance planning still matters.
Understanding SRCC ratings and certifications lets homeowners and professionals select solar thermal solutions that are reliable, certified and optimized for real-world performance — and lets manufacturers meet global standards with confidence.
