Knowledge Nugget: What makes Sitapur Solar Project first of its kind in India?

2. “This is the first-of-its-kind project undertaken by the Ministry of Defence (MoD), involving the development of a large-scale solar power generation facility with integrated BESS support on defence land,” the statement from the Ministry noted.

3. The Ministry stated that besides strengthening long-term energy security for the defence forces, the project is expected to substantially reduce expenditure incurred on procurement of conventional grid power for defence establishments, resulting in significant savings to the government exchequer over the life cycle of the project.

4. “The project will be implemented in close coordination with Integrated HQ of MoD (Army) and Directorate General Defence Estates (DGDE),” it said, adding that the project represents a convergence of national security, energy security, technological innovation and environmental sustainability.

5. The solar power project in Sitapur is expected to emerge as one of the country’s most significant renewable energy projects established on defence land and a benchmark for future solar-plus-storage projects in the defence sector, it added.

Energy Storage Technologies

As the approved establishment of a 250 MW solar power project in Sitapur includes a battery energy storage system, let’s know what it is and other energy storage technologies.

1. Energy storage refers to systems that can store excess renewable electricity during periods of high generation and discharge it when demand rises but power generation remains low.

2. At its core, energy storage systems convert electricity from renewable sources such as solar and wind, when it is available, into forms that can be stored. Later, it converts these back into electricity when need arises.

3. A range of energy storage technologies are being deployed globally. Among them, pumped hydro storage (PHS) and battery energy storage systems (BESS) are currently the most widely used.

(i) PHS uses surplus electricity to pump water from a lower reservoir to a higher one. When electricity demand peaks, it releases the stored water downhill through turbines to generate power.

(ii) BESS technology stores electricity chemically and discharges it when needed. Lithium-ion batteries, particularly lithium iron phosphate (LFP) batteries, are currently the dominant technology for grid-scale storage because of their falling costs, high efficiency and long operational life.

4. Beyond PHS and BESS, several other energy storage technologies exist globally at smaller scales. Such as:

(i) Concentrating solar-thermal storage systems: This technology uses mirrors that capture and focus sunlight onto a receiver. As the receiver gets heated, materials such as molten salt are circulated inside the receiver to store the heat. The stored heat can later be used to produce steam. This steam is converted into mechanical energy in a turbine, which powers a generator to produce electricity.

(ii) Compressed-air energy storage systems use excess electricity to compress air and store it in underground caverns or tanks. When power demand rises, the compressed air is released to drive turbines and generate electricity.

(iii) Flywheel energy storage systems store electricity as rotational energy by spinning a rotor at extremely high speeds. Because they can inject power into the grid almost instantly, they are particularly useful for maintaining grid stability and managing short-term fluctuations.

(iv) Gravity energy storage systems use electricity to lift heavy weights to higher elevations. When electricity is needed, the weights are lowered, converting gravitational energy back into electricity through generators.

BEYOND THE NUGGET: India’s new domestic solar cell mandate

1. According to a Union government mandate, only locally manufactured solar cells can be used in domestic, commercial and industrial solar projects from June 1.

2. Cells — components that convert sunlight into electricity — are the building blocks of solar modules, the panels used to generate power.

3. This domestic cell sourcing mandate is aimed at reducing India’s dependence on imports and strengthening the domestic solar manufacturing ecosystem.

Post Read Question

(Sources: Rajnath approves ‘first of its kind’ solar project in Uttar Pradesh’s Sitapur, UPSC Weekly Concepts Snapshot: Energy storage technologies, Bond Yield and ENSO, From June 1, solar projects must use only locally made cells: Why this raises concerns)

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