In March 2026, the National Institute of Solar Energy (NISE), India, successfully obtained accreditation from the National Accreditation Board for Testing and Calibration Laboratories (NABL) for the calibration of pyranometers (according to ISO 9847:2023) and solar photovoltaic (PV) reference modules (according to the IEC 60904 series).
This achievement marks an important step in strengthening India’s national quality infrastructure for the photovoltaic sector and represents a major milestone for NISE in its ambition to become one of the world’s leading reference institutes in the field of solar energy.
The accreditation is also the result of more than a decade of cooperation between the Physikalisch-Technische Bundesanstalt (PTB), Germany’s national metrology institute, and NISE, within the framework of Indo-German development cooperation, funded by the Federal Ministry for Economic Cooperation and Development (BMZ).
This collaboration began over 12 years ago with an assessment of the quality infrastructure needed to support India’s rapidly growing PV sector. At the time, the solar industry in India was expanding quickly, but systematic quality assurance had not yet become a central priority for many stakeholders.
Through joint studies on PV plant performance, stakeholder dialogues, and awareness-raising activities, the cooperation helped highlight the importance of accurate measurements and quality assurance for the long-term performance of solar installations. Today, quality assurance is widely recognised as a key pillar of India’s PV sector.
A crucial element of the collaboration was the technical support provided by leading German institutions, including the Fraunhofer Institute for Solar Energy Systems and the Lindenberg Metrological Observatory, an institute of the Deutscher Wetterdienst (Germany’s national meteorological service). Over the course of several years, experts from these organisations trained and advised NISE specialists, which helped to build the technical capabilities required for internationally recognised calibration services.
The new accreditation brings important benefits for the solar sector in India. Calibrated PV modules serve as essential references for testing laboratories and solar manufacturers, allowing them to verify the performance of their products against modules with precisely known electrical characteristics during development, production, and testing. Having these calibrations available within the country is particularly valuable, as calibrations performed overseas take a lot of time, and reference modules are difficult to transport internationally due to the risk of changes in their characteristics or physical damage.
At the same time, the internationally recognised accreditation of pyranometer calibration ensures accurate measurements of solar irradiance — the amount of sunlight reaching the Earth’s surface. Reliable irradiance data is crucial for planning new solar power plants, evaluating site potential, and monitoring the performance of operating PV installations.
By confirming the validity and reliability of the new calibration services, the accreditation directly supports the continued development of a high-quality and high-performance solar sector in India.
