A Guide on Battery Storage Certification for Renewable Energy Sector

India is taking rapid steps to modernize its electricity generation with a multipronged strategy. A significant part of the modernization strategy is to evolve the generation mix by increasing the capacity to produce electricity from hydroelectric and renewable energy. These electricity generation methods are cost-effective and can potentially make the grid smart, wherein it automatically adjusts electricity flows to avoid imbalances that could lead to blackouts. The adoption of grid-scale battery energy storage systems (BESS) is crucial to diversifying the generation mix and supporting the country’s modernization plans.

BESS technologies can help eliminate the need for building a newgrid (to support the ageing grid), enable deployment of a smart grid, facilitate peak demand economics, improve grid reliability and resilience, foster grid balancing and load levelling. Battery storage technologies such as Lithium-ion play a vital role in integrating intermittent renewable energy sources, such as solar and wind, into the power system. The battery storage can charge with inexpensive renewable energy when the demand is low and discharge during high demand periods (when the unit cost is high).

The cost of deploying battery storage technologies is plunging drastically across the world in the last few years due to the economies of scale in manufacturing. Simultaneously, the cost of power generation has been on the rise, making battery storage an imperative, especially for the renewable energy sector. India took its first steps to deploy battery storage in the renewable energy sector in 2019 when the Solar Energy Corporation of India Limited (SECI), under the Ministry of New and Renewable Energy, began specifying battery storage requirements in its calls for tenders.

While the momentum for leveraging BESS in India’s renewable energy sector has been created, recent fire accidents involving mostly Lithium-ion battery storage systems in the U.S., Europe, Australia and South Korea underscore the need for safety standards.

The compelling need for safety standards

The main causes of these accidentswere lack of safety and environmental controls, insufficient insulation and fire protection mechanisms, and inadequate installation codes. A safety testing, certification and inspection regime based on relevant standards and codes is essential to help ensure the safety, security and sustainability of battery storage. The system-level certification becomes vital to enable safer and reliable power plant installations. However, screening and matching individual cells in batteries can prove difficult as billions of cells are manufactured globally every year for storage applications.

Moreover, cells are assembled into batteries in the ‘as received’ condition at a lower state of charge (typically 40 per cent) to be cost-effective. Also, cell-level abuse test performance does not equal battery-level characteristics. For the safe performance of battery storage, cell, battery and module-level tests in the relevant configuration and environment are a must, considering they are exposed to temperature, vibration, shock, humidity and corrosion. In addition to the requirements mandated by SECI and efforts for establishing standards by the Bureau of Indian Sta), a conformity scheme covering the entire value chain from cell to infrastructure-level is necessary for the safe performance of battery storage systems.

Existing SECI requirements

The table outlines the exact requirements defined for the renewable energy sector by SECI.

BIS efforts to develop Indian Standards

The BIS has set up a Technical Committee, ETD 52, for developing Indian Standards. In the meantime, BIS has adopted standards for batteries such as IS 16046 (Part 2):2018/IEC 62133- 2:2017 for Secondary Cells and Batteries Containing Alkaline or Other Non-acid Electrolytes- Safety Requirements for Portable Sealed Secondary Cells and for Batteries Made from Them for Use in Portable Applications Part 2 Lithium Systems. At present, IS 17092, the electrical energy storage (EES) standard developed by BIS, and IS 17387:2020 for General Safety and Performance Requirements of Battery Management Systems are the standards dealing with the safe performance of storage systems.

However, India needs to adopt standards and codes like UL 9540A and NFPA 855 even as it creates a full-fledged regime that suits Indian conditions. With India’s ambitious plans for increasing its capacity for generating renewable power, moving away from coal-based plants and the strategic energy security considerations, battery storage has an important role to play. As the deployment increases in the country, the economies of scale would set in and help bring down the costs. Testing, certification and inspection regime can help ensure the safety of battery storage systems, creating a sustainable environment for the renewable energy sector.

- Sriparn Saurabh, Engineering Manager,  Solar Projects, UL - South Asia