ApplicAtion of new technology SolutionS for MiniMizing Land use for overhead transmission lines – Indian Experience

Indian Power System has grown rapidly in the past two decades. The transmission lines traverse length & breadth of the country. Due to high population density, growth of habitation & infrastructure, the right of way constraints and environmental concerns have increased substantially over the years with the growth of the transmission network. Power Grid Corporation of India Ltd. (POWERGRID) as part of its efforts for sustainable development of transmission network in the country, has taken various initiatives involving new technologies/new innovative solutions aiming to minimize the environmental impact and land use of transmission lines. One of the major features of the development of transmission network has been adoption of high voltage bulk power transmission lines. With introduction of 765 kV Double Circuit transmission lines, +/- 800 kV UHVDC and 1200 kV UHVAC transmission lines in the country, which are presently under construction, there is quantum reduction in the right-of-way (ROW) requirement per MW of power transferred. As yet another initiative to minimize the land use and environmental impact of transmission lines, use of multi-circuit towers has been brought into practice. Further, since construction of multi-circuit towers with quadruple bundle conductors involve substantial resources, efforts & cost, new technology High Temperature Low Sag (HTLS) conductors are being used for reduction in bundle conductors (from quadruple/triple bundle to twin bundle). The paper highlights various examples of initiatives taken by POWERGRID in application of new technology solutions to minimize the land use and impact of transmission lines. Actual cases of adoption of 765 kV double circuit lines, +/-800 kV UHVDC lines, 1200 kV UHVAC lines, 400 kV multi-circuit lines with HTLS conductors, 400 kV double circuit tubular/pole structures with HTLS conductors etc. have been described. Salient features and results of techno-economic studies & developmental activities undertaken for realization of such initiatives have also been presented in the paper.