From pv magazine 04/2020
PI Berlin was contracted by the German Corporation for International Cooperation (GIZ) in 2019 to investigate rooftop PV system performance in India. The purpose was to identify the causes of underperformance in 40 preselected rooftop PV plants across the country, quantify them in terms of contribution to generation losses, and propose cost-optimal solutions to address the quality issues.
The results of the evaluation show that the low performance of the inspected PV plants is caused by a mix of disregarded design constraints, installation failures, and product defects. Specifically, the main detected issues are potential induced degradation (PID), heavy soiling, shading, and module damage during transport and installation.
According to the observations and measurements conducted during the site assessments, these key findings have contributed individually to losses at the system level between 6% and 30%. The results of this study (“Moving from kW to kWh”) were published online on a purpose-built website. The suggested measures to rehabilitate the plants to their expected performance levels would require additional investment (capex) and ongoing operational costs (opex) that would dramatically reduce the expected investment returns. These drastic financial consequences are a direct result of cutting corners with respect to quality considerations at the beginning of the projects. One of the goals of the study was to identify potential benefits for O&M contractors and developers in existing and future projects based on the findings. In this sense, PI Berlin suggests five revamping and repowering measures which, depending on the state of each PV plant, may lead to a performance boost between 5% and 50%. PI Berlin proposed 10 affordable prevention mechanisms for new projects that include technical and commercial recommendations to ensure their long-term viability.
The quality deficiencies discovered at the Indian sites can only be addressed with a comprehensive quality control program, defining quality criteria and assurance mechanisms developed for all of the major phases of a PV project. Ideally, this approach would be adopted across the PV sector to ensure that all new power plants built in India would be assured long-term viability.
- The PI Berlin study is part of the Project Indo-German Solar Energy Partnership – Photovoltaic Rooftop Systems (IGSP-PVRT) and is financed by the German Federal Ministry for Economic Cooperation and Development. It is implemented by GIZ in partnership with the Ministry of New and Renewable Energy (MNRE).
- The project, “Strengthening quality infrastructure for the solar industry” is implemented by Physikalisch-Technische Bundesanstalt in cooperation with the National Institute of Solar Energy (NISE) and financed by the German Federal Ministry for Economic Cooperation and Development (BMZ).
- Solar Energy Corporation of India ltd (SECI) is under the administrative control of the Ministry of New and Renewable Energy (MNRE), set up on Sept. 20, 2011, to facilitate the implementation of the Jawaharlal Nehru National Solar Mission and the achievement of its targets.
- Indian Renewable Energy Development Agency Limited (IREDA) is a government of India enterprise under the administrative control of the MNRE. IREDA is a public limited government company established as a non-banking financial institution in 1987. It is engaged in promoting, developing, and extending financial assistance for setting up projects relating to new and renewable sources.
In this regard and acting on behalf of the National Metrology Institute of Germany Physikalisch-Technische Bundesanstalt (PTB), PI Berlin conducted two actions. Firstly, it launched a review of the latest versions of both the rooftop and utility-scale tenders released by SECI, with the goal of reinforcing the quality requirements and significantly reducing the number of quality issues encountered during the construction and operation phase. These tenders are key as they determine right from the beginning the future quality of the PV projects with regard to design, construction, and O&M.
Secondly, and building on the reinforcement of the SECI tenders, a “Construction Monitoring Tool” was created for IREDA and other Indian financing institutions to support the evaluation of solar PV assets during the construction stage. This instrument is particularly important because it provides a final risk assessment, based on a rating classification, through a scoring and weighting system. Using this tool, banks and financing institutions will be able to better adjust their financing conditions, based on the assigned rating and risks.
Considering the benefits that quality assurance brings in terms of prevention of unintended financial consequences, opex savings and an increase of bankability, is the investment in proper quality assurance really too expensive? An initial investment in quality control contributes to properly assess the real opex during operation and avoid an inflated capex at the expense of opex, in order to obtain better financing conditions. Transparency in the financial modeling is only possible with solid intelligence gained during product selection and manufacturing control. With increasing demand, the momentum gained in the Indian PV market requires laying the foundations for a future that ensures investor confidence, reliable energy generation and, especially, the reputation of the Indian PV market worldwide.
About the author
Asier Ukar is a senior consultant at PI Berlin and the managing director of its Spanish subsidiary, PI Berlin S.L. He has 13 years of experience in the deployment of rooftop and multi-megawatt, grid-connected PV systems, with a physical presence in Europe, Asia, Latin America and Africa. He has been active in the Indian market since 2010. He has also been involved in the design, supervision and refinancing of approximately 3.5 GW of installed capacity throughout the world since 2007. Ukar holds a diploma in mechanical engineering from the Technical University Karlsruhe.
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