Pumped Storage Projects

Source-This post on Pumped Storage Projects has been created based on the article “The relevance of pumped storage projects” published in “The Hindu” on 2 August 2024.

UPSC Syllabus-GS Paper-3- Infrastructure: Energy, Ports, Roads, Airports, Railways etc

Context-The Union Budget 2024-25 introduced a policy to boost pumped storage projects to help integrate renewable energy into the power grid. India currently has 3.3GW of pumped storage, with key sites at Nagarjunasagar, Kadana, Kadamparai, Panchet, and Bhira.

What are types of Pumped Storage Projects?

Pump storage comes in two types: on-river and off-river.

A) On-river projects are hydroelectric plants supplied by rivers.

B) Off-river projects use two reservoirs at different levels. Water is pumped up from the lower to the upper reservoir when there is surplus power and flows down to generate power when needed.

What is the importance of pumped storage projects?

1) Solution for Renewable Power Variability -To tackle the variability and intermittency of renewable power from sources like solar and wind, pumped storage using water has emerged as a globally preferred solution. This method functions like a large natural battery, storing and releasing energy by moving water between reservoirs.

2) Renewable Energy Goal -India plans to reach 500GW of non-fossil fuel energy by 2030. To achieve its renewable energy targets, India must greatly increase its pumped storage capacity.

3) Renewable Power and Stabilizing Supply– They are important for India’s policy of maximizing renewable power use and minimizing curtailment. By storing excess power and releasing it when needed, they provide the flexibility required to stabilize the power supply.

Read More- Investing in pumped-storage hydropower (PSH) helps India’s transition to clean energy

How does pumped storage at Kadamparai operate?

1) Plant Operations and Storage – The Kadamparai plant in Tamil Nadu has four 100 MW units and uses two reservoirs. Water flows from the upper reservoir to the lower one to generate power, and when there’s excess power, it’s used to pump water back up for storage. The upper reservoir contains about 1 TMC feet of water, with minor leaks replenished by rainfall.

2) Solar Energy Use for Pumping-During peak solar times, usually at noon, excess power is used to pump water. Each unit needs 20% more power to pump water than it generates, but this extra power comes from solar energy, so no fuel is used.

3) Capacity -The plant takes about 90 minutes to switch from pumping water to generating power and another 30 minutes to start production.  It can produce 400 MW for 3-4 hours during peak evening hours and may operate at a lower capacity late at night.

Question for practice

What types of pumped storage projects exist? Why is pumped water projects important? How does the pumped storage system at Kadamparai function?