Solar Hot Water Standards and Certifications – Pathways to 2030
Deliverable D1
January 2025 - PDF 0.49MB
Editor: Elsabet Nielsen and Jianhua Fan

In the past, solar hot water (SHW) systems were mainly designed using traditional solar thermal collectors, specifically thermosyphon collectors. However, new technologies, for example PV to heat systems (PV2heat) and smart components, are promising to enhance the overall performance and decrease the system capital cost. This creates the need to develop new standards, add new technologies/configurations, and revise the current standards.

This report focuses on the current international series of standards for SHW systems, ISO 9459, and how to improve and revise the standards to cover all existing and new technologies for reliability, durability, and performance, focusing on thermosiphon and PV2heat solar water heaters (SWH). Further, the status of selected Quality Certification networks is included in this report.

The investigation shows that the existing international Standards for SHW systems, ISO 9459, cover thermosyphon systems, but not yet PV2heat systems.