The company, in a major shift, has decided to take the national approach, replacing the existing regional self sufficiency concept, depart from generation-linked projects and create transmission highways from potential resources to major load centres for conservation of right of way and achieve economy (cost per mw) in the long term.

PowerGrid sources told The Financial Express that the company in its corporate presentation submitted to the union Ministry of Power has stressed the need for the formation of a national grid in view of the "uneven distribution of exploitable energy resources in the country." The formation of a national grid is also necessary for the optimal development of available energy resources.

PowerGrid, which has been entrusted with the task of forming a national grid by the union Ministry of Power, has planned a number of schemes for the phased development of a national grid, "considering the wide variation in operational parameters of the regional grids, to start with, high voltage direct current (HVDC) interconnections for northern, western, southern and regions. It has already made operational HVDC back-to-back links between northern region and western region (500 mw) at Vindhyachal, western region and southern region (1,000 mw) at Chandrapur, eastern region and southern region (500 mw) at Guzuwaka. A similar link between eastern and northern region (500 mw) at Sasaram would be ready by 2002.

"These links would complete the basic framework of national grid. Cumulative inter-regional transfer capacity has been enhanced to 4,500 mw," PowerGrid sources said and added that subsequently, the grid would be strengthened through hybrid systems consisting of high-capacity HVDC and extra-high voltage lines.

Additional inter-regional links would be completed by 2004. The company has considered mega-size thermal projects in Orissa (Talcher-II, Hirma) and hydro-projects in the north-east. The proposed beneficiaries with these projects would be states of southern and northern regions.

In order to evacuate power from these generation projects, additional inter-connection between various regions has been planned as a mid-term phase. The major schemes are east-west AC inter-connection (Rourkela-Raipur), east-south 2000 mw HVDC Bipole (Talcheer-Kolar), east-north high-capacity 400 kV link (Purea-Gorakhpur) and east-north high capacity (HVDC or 765 kV) links with Hirma. "With these inter-connections, the total inter regional power exchange capability would be increased to about 14,000 mw," PowerGrid sources said.

In the last phase, a strong synchronous national grid has been envisaged to evacuate power from major generation resources, including hydro projects in the north-east and large sized thermal plants in Bihar, Orissa and Madhya Pradesh.

"The scheme for ultimate national grid would involve development of high-capacity transmission corridor in chicken-neck area and the establishment of a ring of 765 kV interconnecting eastern, western and northern regions. Cumulative inter-regional transmission capacity of the proposed ultimate national grid would increase to about 30,000 mw," these sources said.

As far as formation of a Saarc grid is concerned, PowerGrid has said that these countries have very low per capita energy consumption in spite of the fact that most of them are endowed with abundant natural resources. As per the estimate, the hydro potential of Bhutan is 21,000 mw, Nepal-83,000 mw and Pakistan-36,000 mw. Similarly, Bangladesh has gas potential to the tune of 40,000 bcf.

According to PowerGrid sources, harnessing of these resources, so far, have been done in a limited way. The development was hindered mainly due to relatively low level of domestic demand, which does not justify the development of large-sized projects. However, under the proposed Saarc grid project, composite transmission system has been envisaged for hydro projects in Nepal.