New Delhi

In the ecologically fragile Andaman and Nicobar islands, it has been a constant challenge for the authorities to meet the ever- growing need for power and yet minimise polluting diesel generators, usually used in such areas.

Enter NLC (formerly Neyveli Lignite Corp) India’s solar power project with Battery Energy Storage System (BESS) that is a use case for eco-sensitive zones including Ladakh, where the government aims to create its first carbon neutral territory.

The lignite-miner’s 20-MW solar PV power project with 8 MWh BESS in South Andaman, executed by Larsen & Toubro (L&T) that has been up and running since late 2020 has not only helped save around 8,000 kilolitres of diesel annually, but also cut costs of generating power and tariffs for the consumers.

The average cost of electricity supplied through diesel generators in the islands is ₹26 per unit and fuel consumption is around 269 per millilitres per kilowatt hour (kwh), or unit. The annual guaranteed energy export from the project is 26.8 million units with a capacity utilisation factor (CUF) of 15.88 per cent and a tariff of ₹6.99 per unit, which not only brings down the cost of producing power but also leads to lower use of diesel leading to lower emissions.

NLC India’s 20-MW solar PV power project with 8 MWh BESS in South Andaman

NLC India’s 20-MW solar PV power project with 8 MWh BESS in South Andaman

Of course, it was not easy to do the project. Usually, you need contiguous land to set up solar panels as they follow the land contours. But there was only highly sloppy terrain available at Port Blair so the module mounting structure has been designed to match the ground profile as well as the high rainfall in the region. No major earth cutting or filling was done during project execution. Also power evacuation from one of the sites (Attam Pahad) is through underground cables which are laid 1.2 meters beneath the soil layer of the backwaters.

Grid scale storage

In a first for the sector in India, the grid scale storage project spread over 101 acres can be integrated with solar Photovoltaic (PV) cells for smoothening solar power variability due to cloud cover. Besides, it can be used to charge the BESS during daytime for supply of power during non-solar hours thereby curbing the use of diesel for power generation.

The government is also working on similar projects in Andaman and Nicobar. This includes a 15-MWhr BESS to be established by Japan International Cooperation Agency (JICA) under a grant-in-aid scheme and another 20 MWhr BESS as per the RE plan approved by the Ministry of New & Renewable Energy.

This assumes importance as Prime Minister Narendra Modi, during a poll rally in Junagadh (Gujarat), expressed a desire to develop some of the 1,300 islands in India - some as big as Singapore – for tourism.

The project is highly replicable, especially in Ladakh. As a Coal Ministry official explains, “Ladakh has the best solar potential in India. Whereas, the power demand there is less. BESS can be employed to store excess energy and use the same for smoothing power output and maintain grid stability. The challenge of distributed grid connected solar PV projects can be mitigated through this design and the reliance on other sources for balancing can be avoided.”