Thayannankudi is a very old Muthuvan tribal settlement in the Chinnar Wildlife Sanctuary along the side of River Chinnar in Idukki District, Kerala. There are 48 families and nearly 200 members in this settlement as per the management plan 2012– 2022, and there was no electricity or communication facility in the settlement. Most inhabitants of the colony are dependent on agriculture and the forest for their livelihood. Being located in the rain shadow region of the sanctuary, the availability of South–West monsoon in the sanctuary is very poor but retreating South–West monsoon and North– East Monsoon gives an advantage to their agriculture and other livelihood practices. Other than the houses and common gathering places, there are some agricultural farm houses and store houses that needed power back up. Originating from the laps of Eravikulam hill ranges, which flanks in the north–west side of the sanctuary, River Chinnar is a perennial water source for the sanctuary and this colony. Deserving the status of a protected area and owing to the huge investments required, the settlement was not allowed to use utility lines for electric supply. In order to satisfy their power demand, solar power system had been installed long back, when the technology was not that mature. Due to a lack of proper maintenance and management, the system turned out to be a failure with time. In this circumstance, an alternative way of energy generation was suggested taking advantage of the perennial Chinnar River by installing a micro hydropower system availing the government subsidy rate for the electrification in Thayannankudy tribal settlement. Micro hydropower systems are beneficial in terms of cost and simplicity from different approaches in the design, planning, and installation than those that are applied to larger hydro power.

Recent innovations in micro-hydro technology have made it an economic source of power even in some of the world’s poorest and most inaccessible places. Through this means, power can be generated, enabling standard electrical appliances to be used and the electricity to be distributed to the whole colony. The Thayannankudy tribal colony can utilize devices, such as LED bulbs, radios, television, refrigerators and food processors, agricultural machines, etc., which can be powered by micro hydro. This has added to the socioeconomic development of the forest-dependent tribes of this colony and has provided a better livelihood for them to combat the human–wildlife conflict.

Thayannankudi is situated 4 km inside the forest from Chinnar main road near the Chinnar check post under the Forest Department. There is no electric grid connection available for this settlement. There are about 50 houses (around 200 inhabitants) including a school, Anganwady, community hall, and Chathram in and around the colony. The River Chinnar flows near this village.

From this river, water is diverted and taken by a channel through the village for irrigation purposes. The existing channel for irrigation was modified and rectified for drawing water into the turbine. Along the channel it was noted that at many places down the channel towards the river, to find the necessary head to generate power, the water can be let off to the Chinnar River. At a place where the channel enters the Kudi, there is a head of approximately 7 m obtained with an underground powerhouse. At this point, an inlet tank cum filtration tank was constructed on the channel with an overflow arrangement and the water is drawn through a penstock and valves to the hydro turbine and the tailrace water is let in to the river again after irrigating the terrain.

Underground Powerhouse

A turbine shed (underground) measuring 3 m × 3 m was constructed as a powerhouse. From this point, power is evacuated through transmission lines and then distributed to individual houses by proper cable arrangement. The houses are scattered across the settlement and a few of these houses are at a long distance.

Table 1 presents the salient features of 3 kW Thayannankudi pico hydropower project in Kerala.

The power is evacuated from the generating station to the colony through a suitable three-core armoured cable and to the individual houses through distribution cables from the respective poles. Complete electrification of houses and other common amenities, including providing service wires, MCBs, switches, and plug sockets, as well as fixing of a 9 W LED bulbs for lighting and streetlights have been provided. The entire scheme was conceived and implemented by the Energy Management Centre (EMC) with financial support from the Ministry of New and Renewable Energy (MNRE) and the Forest Department.

The electrification carried out successfully is as below.

• A total of 48 house houses with 2 × 9 W LED bulbs
• The community hall with 2 × 9 W LED bulbs and 3 plug sockets
• The school with 6 × 9 W LED bulbs and 2 plug sockets
• The Anganwady with 6 × 9 W LED bulbs and 2 plug sockets
• The Chathram with 6 × 9 W LED bulbs with 2 plug sockets.

Recently, the Forest Department implemented another project making use of the tail race water of this micro hydroelectric plant. The tail race water of this plant is used to refill ‘Punarjani’ a check-dam deep inside the forest, which is a grass land of the sanctuary, almost 6 km from the powerhouse. Usually, the checkdam goes dry during severe summer months forcing the wild animals to move out of forest to human habitations in search of water, which causes man–animal conflicts. Further, the intervention could prevent the death of small species, such as star tortoise. Earlier, forest personnel used to fill up these ponds periodically, which is a costly and time-consuming affair due the location of the checkdam and the evaporative losses during the summer season. It can be said that the Thayannankudi micro hydropower scheme is a decentralized plant catering to the isolated tribal community with electric power and by drawing the tailrace water to fill up a check-dam inside the sanctuary it quenches the thirst of wild animals and it is also very unique.

Mr Anil G, Joint Director, Energy Management Centre (Under Department of Power, Government of Kerala), Sreekariyam, Thiruvananthapuram 17, Kerala, India.