DESIGN OF ELECTRIC NETWORK AND ELECTRIC ENERGY PRICING FROM RURAL ISOLATED PLANTS - A CASE STUDY OF YAKLA S.I.P.

Abstract

The implementation of small hydro electric projects in remote and isolated area is not always cost effective due to logistic problems and poor average plant factor. The distribution of power to different load centres, situated at dispersed locations, becomes problematic due 0 to large cost involvement in the distribution systems. If the distribution system. is not planned properly, there will be substantial increase in the cost of implementation thereby -increasing the cost of energy to a great extent. On the otherhand, if it is not designed scientifically, there will be enormous amount of losses of energy. Hence, proper care should be taken for the above factors while planning and designing the distribution network. Under the scope of the present study various aspects of designing the distribution network for 415 V, 11 kV and 33 kV systems have been discussed. Various methods and approaches for designing the distribution system have been studied and techno-economic viability of different alternatives have been compared. As not much literature about designing a distribution network for a remote area to be supplied from a small power station that run in isolation, could be made available, the study has been based on various technical specifications, construction' standards and guidelines of different ..cuing agencies. A rlo. t computerised teehnues have been developed *,.•r designing distribution network with a particular attention to selection of conductors for overhead lines and sizing of cables for L.T. applications. A few worksheet models, based on MS-Excel Software, have been prepared for the purpose of cost estimation of different types of distribution 3v,c . .i_t tcnls These ..' ' 1 ~f i~ ,. can e UsCCi +ll knU'JV i iUt various cost c^Cii r ili:rlci various combination of different structural materials used in overhead lines in order to take ' cost effective decisions. Cost of energy for a rural isolated SHP project has been calculated through different methods and after comparing these, methodologies for fixing of energy ii price have been discussed. As a case study, design of the proposed distribution network has been prepared for an isolated micro hydel project at Yakla in Sikkim after carrying out preliminary load survey for assessing the load demand. For designing this distribution system various alternatives have been compared and accordingly the suitable one is suggested. The cost estimates for the proposed scheme have been prepared on the basis of local standard schedules. Efforts have been made for detailed analysis of various design aspects and adopting the most suitable method so that implementation of SHP projects in rural isolated areas may be cost effective.