Why is it in the news?

• As India aims for half of its electric power capacity to come from renewable sources by 2030, the need for a resilient and stable power grid is critical.
• Unlike traditional energy sources that provide consistent output, renewables like wind and solar are variable and dependent on weather conditions, posing challenges for grid stability.

An Analysis

• Renewable energy generation fluctuates, requiring the grid to be flexible to match power generation with demand. Currently, renewables make up about 10% of India’s energy portfolio, but this share will increase significantly as capacity grows.
• Without battery storage, electricity must be generated in real-time to meet demand, which can lead to significant supply imbalances if not managed properly. For example, a 3% error in scheduled dispatches from a 500 GW renewable capacity could result in a 15 GW supply shortfall.
• To address these challenges, ancillary services are necessary for balancing supply and demand. These services can be categorized into three types:

1) Primary Services: Respond to fluctuations in less than a second and can be provided by hydroelectricity and battery storage.

2) Secondary Services: Address changes within 10-15 minutes, typically using gas-based capacities.

3) Tertiary Services: React in 20-30 minutes, relying on thermal power plants, including coal-fired ones.

Case Study: The Covid-19 Lockdown

• An illustrative example of grid management occurred on April 5, 2020, during the Covid-19 lockdown when Prime Minister Modi urged citizens to turn off lights for nine minutes.
• This sudden load reduction of about 15 GW required quick adjustments, which were managed by reducing power generation from thermal, gas, and hydropower sources in advance.
• Hydropower’s rapid responsiveness was crucial, allowing for a quick ramp-up of generation to meet the surge in demand, unlike gas and thermal sources which require more time.

Necessity of Battery Energy Storage Systems (BESS)

• As the share of renewables increases, the deployment of Battery Energy Storage Systems (BESS) becomes essential. BESS can respond to grid contingencies within seconds, providing crucial services such as frequency control, voltage regulation, and peak shaving.
• Recently, a pilot project in New Delhi demonstrated BESS’s capabilities, providing reliable power to low-income consumers.
• The Central Electricity Regulatory Commission has identified the need for 4 GW of storage capacities to ensure grid flexibility.
• By 2031-32, India anticipates a total storage requirement of 73.93 GW, predominantly from BESS, highlighting its importance in supporting a renewables-heavy electricity grid.