Ullunkal HEP

Power generation

Ullunkal HEP 7 MW (2 x 3.5 MW)

Ullunkal Small Hydro Project is situated between Kakkad Power House and Maniyar Barrage on River Kakkad, a tributary of Pamba. It is located in Chittar Panchayat of Rani Taluk, Pathanamthitta Disrict in the state of Kerala.


The Ullunkal project was conceived in the early Nineties when Kerala State Electricity Board (K.S.E.B.) proposed Ullunkal and Karikkayam as two small hydro projects in cascade on Kakkad River downstream of Kakkad Project to tap the head potential of 30 m between the Kakkad Power House and downstream Maniyar Barrage. The advantage of these projects was that they would get controlled release of water from the existing upstream Sabarigiri H.E.Project(360 MW) routed through the Kakkad Power House (50 MW) and utilize the above head potential. Another advantage was that it helped avoid submergence of larger land area.

The project was initially allotted to Travancore Electro Chemical Industries Ltd. (TECIL) in 1994 from which EDCL successfully acquired it. At the time of acquisition, 80 % of the civil work was completed and major portion of the electromechanical equipment had been delivered. EDCL completed the project and commissioned it in 2009.

Project Description

It consists of a 16 metre high diversion concrete gravity weir with gates spanned across river Kakkad and a weir-toe surface power house with an installed capacity of 7 MW(2X3.5 MW) located on the left bank of the river.

The power outlet block is used for taking in water from the Dam to the power house. The power outlet block accommodates the trash racks, intake gate structures and power intake penstocks.

The water issuing from the turbines (Horizontal shaft, S Type, Full Kaplan -2 of 3.5MW each) is discharged directly to the river through a tail race.

Energy Generation

The plant is estimated to generate about 32 million units (MUs) of clean, renewable energy annually based on flow duration data compiled from 1981 to 1992.


The energy generated is evacuated at 11 kV line by a dedicated double circuit overhead line from the Ullunkal Power House to K.S.E.B’s Kakkad Power House Switch Yard.

MNES Subsidy and Carbon Credit

The project area falls in the hilly region of other states and is entitled for Rs.3.25 crores MNES Subsidy.

In Kerala, 656 CER units are generated per million unit. Correspondingly, the project with clean energy generation of 32.84 MUs qualifies for Carbon Credit benefits to the tune of about Rs. 9.48 Millions.

Capacity 7 (2×3.5) MW
 Generation  Over 30 MUs
 Commissioned  2009
 Location  Ranni Taluka, Pathnamthitta District, Kerala
Project Cost
 Power Purchase Agreement



Energy Development Company Limited

EDCL HOUSE 1A, Elgin Road

Kolkata-700 020, West Bengal, INDIA