An operational analysis of Kadamparai Pumped Storage Hydro Plant located in Tamil Nadu Sanyasi Naidu J, Sr. Engineer, SRLDC (POSOCO)

Topics Why “Pumped Storage” Hydro Plant SRLDC Why “Pumped Storage” Hydro Plant Introduction: Pumped Hydro Plant “Kadamparai PSP” - A Glance Analysis of operational pattern of Kadamparai PSP Conclusion

Why “Pumped” Hydro Plant SRLDC Indian Govt. has an ambitious plan of installing 175 GW RE by 2022 RE poses challenges to grid operation Need - Quick start & rapid control gen’ Integrating highly variable RE increase the need for energy storage, flexible and controllable generation Need - most reliable, cost-effective, CO2-free & flexible storing methods Low-carbon resources – less flexibility to match demand variation Conventional generation – less than tech min’ limits – More emissions

Introduction: Pumped Hydro Plant SRLDC Current pumped storage round-trip or cycle energy efficiencies exceed 80% It is the most commonly used and most commercially viable large scale electricity storage technology. It currently accounts for 96% of the total storage capacity globally Item in MW Hydro Installed Capacity in India 44600 Designed and capable of operation as pumped storage 4785 Pumped storage capacity is presently under operation in SR, WR & ER 2450 + 706

“Kadamparai PSP” - A Glance SRLDC Commissioned between 1987 and 1989 Though it is 3rd constructed PSP, But 1st to operate as both Generator & Pump Underground PH with four (4) Reversible Francis Turbine units each having a generating capacity of 100 MW. Designed to operate between 49.5 Hz and 50.5 Hz

“Kadamparai PSP” - A Glance SRLDC It generates 100 MW during Gen’ cycle & consumes 110 MW during pumping cycle. Minimum capacity required for generation is 4 MU, and pumping is 0.96 MU. Parameters Kadamparai Dam (Upper Reservoir) Upper Aliyar Dam (Lower Reservoir) Reservoir Capacity 26.85MU 25.91MU FRL (Full Reservoir Level) 1149 meters 762 meters MDDL (Minimum Draw Down Level) 1112 meters 722 meters Dead storage (in Million Cubic Feet) 170 MCFT 23 MCFT Gross Storage (in Million Cubic Feet) 1080 MCFT 938 MCFT Mode Condition Response Time Generator Stand still to on-line 5 min On-line to full load Few seconds Motor Stand still to synchronous condenser 9 min Synchronous condenser to pump 1 min

Analysis of operational pattern of Kadamparai PSP SRLDC Gen’ Mode during Peak Hrs., and Pump mode during night off-peak Hrs. To reduce TN state deviation, to balance TN wind and to meet TN peak requirements. Statistical Analysis: Starts & Stops in a day Gen’ & Pump MW Duration Curve Avg’ monthly Pump/ Gen’ in MU's Capacity Utilization Factor Kadamparai Gen/Pump operation vs TN Dev’ / Wind Gen’ Monthly operation 3D pattern of Kadamparai

Kadamparai Gen’/Pump operation vs TN Dev’ / Wind Gen’ SRLDC Gen’ & Pump Mode within a span of few hours on the same day. Gen’ mode with the sudden decrease in wind generation to reduce over-drawl from grid. Pump mode to counter the sudden increase in wind generation and reduce under- drawl from grid.

No of Starts & Stops, Duration Curve SRLDC On an average around 2 to 7 start/stop operations for each generating unit per day 25% of the time for generation and 22% of time for pumping mode 1 2

Generation details – MU’s & CUF SRLDC Average monthly pump/generation MU of the plant is around 45 MUs Average monthly Capacity Utilisation Factor of the plant is around 30% 1 2

Kadamparai Operation: Gen’ and Pump SRLDC Feb-18 Jun-18 Tamil Nadu Morning and Evening Peak & off-Peak support During high wind period to handle the imbalance created due to intermittent wind generation

Kadamparai Operation: Gen’ and Pump SRLDC Jul-18 Aug-18 During high wind period (June-Aug) to handle the imbalance created due to intermittent wind generation

Conclusion SRLDC TN-SLDC utilising it during peak & off-peak Hrs. to control RE fluctuations. Managing it’s portfolio and getting economic benefits Utilises low cost power @ off-peak Hrs.; Generating @ peak Hrs. (avoiding purchase of high cost power to meet peak demand). Pumped storage scheme utilisation can further be improved Utilising the scheme around 20 to 25% of the time; and CUF is around 30% To operate in a national perspective – Need ‘Regulatory treatment & Market design’ Should fully capture benefits of PSP and reward such assets for the full range of services

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