KOCHI: Struggling to meet the surging power demand during peak hours, the completion of two hydel projects - the 60 MW Pallivasal Extension and the 40 MW Thottiyar project- will bring relief to the KSEB. Though a small step, the completion of the projects, which were abandoned at one stage due to the withdrawal of the Chinese agency, comes as a morale booster to the state power entity. Both projects will be commissioned by Chief Minister Pinarayi Vijayan on October 19.
The Pallivasal Extension and Thottiyar project were launched in 2007 and the machinery, including the main inlet valve, turbine and generator, were imported in 2009. However, the Chinese company withdrew from the project citing various reasons, including dollar conversion issue. Left in the dark, the KSEB abandoned the project in 2012 and the machinery was dumped in temporary sheds. However, in 2019, the KSEB constituted a team of experts, who studied the drawings of the machines and started installing them. Celebrating the successful functional spinning of the generators, the KSEB says it is the biggest achievement as the team has mastered the technical knowhow for the turbines and generators.
“It is a major achievement for the KSEB as the projects were completed without support from the Original Equipment Manufacturer (OEM). The turbine and generator were purchased from a Chinese firm in 2009, but the contract was foreclosed due to some disputes. At one stage the project was abandoned but the board decided to complete the projects in 2019. An expert team was constituted and they installed the machinery based on the drawings. It was a daunting task but it helped to improve our technical knowledge,” KSEB executive engineer K M Shyla told TNIE.
The KSEB has not completed any hydel project in the past 14 years and the last one was the 100 MW Kuttiadi Additional Extension project. Though the power consumption has grown multifold, the board has not been able to take up any new project due to top protests by green activists and restrictions imposed by the Ministry of Forest, Environment and Climate Change (MoEF&CC).
Pallivasal Extension
The Pallivasal Extension scheme has two generators with a capacity to generate 30 MW of power each. The water is brought to the generation station from Ramaswamy Iyer Head Works in Munnar. The barrage was built for the old Pallivasal project. Once the new project is commissioned the old penstock pipeline will be disconnected. The tunnel is 3.5 km long and the penstock pipeline has a length of 1.4 km and is 1.4 m wide.
Though the original deadline to commission the project was in 2014, it was delayed due to multiple reasons. “The construction of the tunnel was the biggest challenge in civil works as the stretch was unstable. There was a landslide in the area in 2018 and the track of the penstock was destroyed,” said executive engineer (civil) K Biju.
The electrical and mechanical works were restarted in 2021. The station can generate 153.9 million units of power a year. “The water pressure at the main inlet valve is 57.5 kg/cm2. The pelton wheel turbine has 20 buckets and 1,500 litres of water is released through four nozzles to make the turbine spin. The turbine is connected to the generator through a shaft. The generator produces 11 KV power which is stepped up to 220 KV through a transformer and connected to the Idukki - Udumalpet line. The modern control system has been installed by Asea Brown Boveri (ABB) and there is a facility to transfer the status and control system to the state load despatch Centre at Kalamassery,” said assistant engineer (electrical) Haridas Vijayan, who is in charge of the installation.
Thottiyar project
The Thottiyar project is located around 1 km away from the Lower Periyar project on the Cheruthoni - Neriamangalam route. Water is brought to the generation station from a weir constructed across Deviyar near Valara Kuthu. The project has a 200 m tunnel and 1,200 m penstock line. The project has one 30 MW generator and a 10 MW generator. The vertical pelton turbines and generators were imported from China.
The project, which was abandoned in 2012, was restarted in 2019. After the Chinese company withdrew from the project, the KSEB invited tender to complete the project but there were no takers. Finally, the board constituted an expert team who installed the machinery based on the drawings. The water pressure at the intake valve is 45 kg/cm2. The project can generate 99 million units of power a year. The power generated is upgraded to 220 KV using a transformer and connected to the 220 KV power line from the Lower Periyar station.
The control system has been provided by ABB. The 10 MW unit was synchronised and connected to the grid on July 15 and has been operating successfully for the past one month. The biggest drawback of the project is the lack of a reservoir. The run-of-the-river project depends on the flow of the river and it will be difficult to operate during summer. There are plans to run the unit using pumped storage during the summer season. The expert team that installed the unit without support from the manufacturer includes assistant executive engineer Benny Paul, and assistant engineers Dinu Varghese, Anoop Eldhose and N Subhash.
Pallivasal Extension
Installed capacity 60 MW
2X30MW
Annual generation: 153.9 MU
Reservoir: Ramaswamy Iyer Head works, Munnar
Tunnel length: 3.5 km
Penstock pipeline: 1.4 km
Penstock diameter: 2 m
Penstock thickness: 44 mm
Inlet valve, turbine and generator imported from China
Control system: Asea Brown Boveri
Water pressure at inlet: 57.5 kg/cm2
Pelton wheel turbine has 20 buckets
Four nozzles to release 1,500 litres of water per second
Discharge of each turbine 6,000 litres per second
Started: 2007 .Completed: 2024
Project cost I600 cr
Old Pallivasal Project
Capacity 37.5 MW
Foundation stone laid by Sri Chithira Thirunal Rama Varma, the erstwhile Maharaja of Travancore, on March 1, 1935.
Commissioning: March 19, 1940, by Diwan C P Ramaswamy Iyer
Stage 1: 3 X 5 MW
Stage 2: 3 X 7.5 MW
Old penstock pipeline to be decommissioned after opening of Pallivasal extension. New Penstock pipeline completed
Length: 1.6 km
Thottiyar project
Installed capacity 40 MW
1 X 30 MW 1 X 10 MW
Annual generation: 99 Million Units
Weir: Across Deviyar near Valara Kuthu
Length of Weir: 222 m
Height of Weir: 7.5 m
Canal length: 60 m
Tunnel length: 200 m
Length of Penstock pipeline: 1,252 m
Started: 2007
Completed: 2024