Arunachal Pradesh-the Land of Raising Sun-with an area of 83,743 is the largest state in the North eastern region sharing international boundaries with Bhutan in the west, China in the North,and Myanmar in the east. The states of Assam and Nagaland flank southern and south eastern borders. Forest covers about 82% area of the State and numerous turbulent streams, roaring rivers, deep gorges, lofty mountains, snow clad peaks and rich diversity of flora and fauna characterize the landscape. The climate varies from sub-tropical in the south to temperate and alpine in the north with large areas experiencing snowfalls during winter. The heights of the mountain peaks vary, the highest peak being Kangte (7090 m above MSL) in west Kameng district. The major rivers that drain the area with their numerous tributaries are Siang, Kameng, Subansiri, Kamla, Lohit, Dibang, Noa-Dehing and Tirap. River Tenga is one of the tributaries of river Kameng.

The North Eastern Region is blessed with the highest Hydro Power potential in the country. The Central Water Commission (Power Wing) as far back as 1957, based on top studies had mad preliminary estimates of the Hydro Power potential of the wings of the North Eastern Region. Based on these top studies, it had been established that there was possibility of Hydro Power potential of the order of 37,400 MW. This potential as estimated was roughly of the order of 32,400 MW from the North bank tributaries and 5000 MW from the South Bank tributaries of river Brahmaputra and other rivers.

The total Hydro Power Potential that has been utilised in the North Eastern Region so far is insignificant and is of the order of 150 MW total installed capacity. This is only about less than ½ of the total available resources. The Kopili Stage – I, Loktak, Lower Barapani and IVth Stage Umiam-Umtru Hydel Projects which are under execution are of the order of 15 MW, 105 MW, 100 MW and 60 MW respectively, out of which benefit from Loktak and Kopili executed in the Central Sector, are expected in 1983/1985 and the Lower Barapani and IVth Stage of Umiam-Umtru Hydel Projects being executed in Assam and Meghalaya State Electricity Boards will yield benefit around 1986-88.

It would thus be seen that inspite of such huge power potential available in the North Eastern Region, this inexhaustible source of Hydel Power which could accelerate the pace of development is yet to be tapped to the fullest extent. There is thus an immediate need to develop this huge power potential not only for the benefit of the North Eastern Region, but also for the rest of the country. Hydel resource which is the cheapest and reliable source of power in the country has to be the first choice and warrant development to the maximum extent wherever possible.

Based on the initial studies, the total generation possible from the Hydro Projects already under investigation and to be investigated would be of the order of 37,400 MW in the North Easter Region. Apart from the Dihang Hydro Electric Scheme of 20,000 MW in Arunachal Pradesh, for which special arrangements should be necessary for manufacture and transportation of very heavy generating units, transformers, etc., it would be possible to have over 5300 MW of Hydro Power in the coming 10 to 15 years for the benefit of the Region and the country.

Besides the above hydro power potential of 37400 MW available in the North Eastern Region, there exists substantial thermal power potential in this region. Presently, the schemes that have been intensified are the Garo Hills Thermal Project in Meghalaya, the Borgolai Thermal Project in Assam and Borjan in Nagaland, all utilizing pit head coal.

Apart from the present installed capacity of 315 MW from Coal, Gas and oil fires stations further generating capacity of 1500 MW exists in the North Eastern Region.

The total investment that would be necessary to add the generating capacity mentioned above both in hydro and thermal schemes in estimated at Rs. 30000 crores and Rs. 1500 crores respectively which will be spread over a period of 25 years from now. With the ever increasing demand of power in the region and the rest of the country, the North Eastern Region can definitely play a very vital role in meeting the power requirements.

The per capita power consumption of Arunachal Pradesh is below 100 kWh as compared to the  national average of 373 kWh. The State plans to harness its enormous natural resources like  forests and hydro power and exploit its mineral wealth to  usher  in an era of economic  development  and  raise the per  capita electricity consumption to 500 kWh by the end of Eleventh Five year Plan period i.e. 2012. The State’s generating capacity was only 32.03 MW  hydro and 28.63 MW diesel till now which has increased substantially with the completion of 405 MW Ranganadi hydro power project 600 MW Kameng H.E. project  is under construction  and  these projects will provide electricity not  only to  Arunachal Pradesh and other states in the north-eastern region but also to other power starved regions of the country.

The  power  scenario  has  therefore  to  be  viewed  in  the  national  perspective.

According to 50000 MW Hydropower Initiative of the Ministry of Power the energy requirement of the country in 2002-03 was 5,45,674 GWh of which only 4,97,589 GWh were available, leaving a shortfall of 8.8%. While the peaking requirement was 81,492 MW, a peak of only 71,547 MW could be met leaving a shortage of 12.2%.

Against the present installed generating capacity of 1,07,973 MW the share of hydro, with  26,910 MW capacity, is only 25%. Thermal (coal, gas and diesel) accounts for the maximum  share of 70% with 76,607 MW. Nuclear capacity is about  3%  with  2720  MW and  wind  1,736  MW  i.e.  2%.

This  is  graphically depicted below :

Most of the regions of the country are suffering from power shortages leading to irregular and  unreliable supply. The problem becomes acute during peak hours. Based on the projections  made in the 16th  Electric Power Survey, an additional generating capacity of over 100,000 MW needs to be added to ensure “Power on Demand” by 2012. This, in effect, means doubling the existing capacity which has been created in the last half a century in the next ten years. Not  only has the capacity to be added but also the present hydro-thermal imbalance of 25:75 has to be corrected  and  brought to 40:60 to meet the peak load requirements, achieve frequency and voltage  stability and provide system operating  flexibility under changing seasonal and diurnal load pattern. For achieving a 40:60 hydro thermal ratio in an installed capacity of around 200,000  MW the total requirement of hydro  capacity will be 80,000 MW which means that  53,000  MW additional hydro capacities has to be created in the next 10 years.

(Source : 50000 MW Hydro-electric Initiative – May 2003)