Summary:

• The activities involved in DPR preparation involve specifying the technical requirements of select schemes, analyzing merits of selected schemes, assessing benefits, developing cost estimates, estimating payback period and return on investment and elaborating the implementation plan.
• Factors to be remain in mind although preparing DPRs are that planning studies might cover a distribution circle/or an urban area, planning and design of distribution system should meet load growth, improvement in reliability/security and quality of power supply, safety of operation, evolving a scientific automation and load management system, better customer service, energy accounting/energy audit, estimation of T&D losses/ segregation of losses, network documentation, technical power loss reduction (short term), commercial power loss reduction, improvement of voltage profile, mapping of the system, data collection and validation of data, voltage variation/regulation study, analysis of the existing system, technical losses in the system, load forecast, upgrading the network/expansion of network, technology options involving integration of modernization of system, evaluation of several alternatives for least cost optimal system, firming up of scope of works and their prioritization, preparation of cost estimates, phasing of works and their cost and financial analysis.
• Intensive field study is needed for DPR preparation. The scheme should describe the area covered under the circle. The existing organisational setup of the circle in respect of administration, planning, construction, operation and maintenance etc, might be given.
• Detailed data about the existing power system should be collected about category-wise number of consumers and connected load, peak demand, annual energy consumption, geographical map, source(s) of power supply, sub-transmission system, distribution system, operational parameters, electrical network details, Equipment Parameter Data, Load Data, System Load Factor and Loss Load Factor (LF and LLF).
• The data compiled for existing system has to be validated for correctness and consistency especially, in respect of load and network data. Every element of investment must be accounted for against the project in consideration. Basic equipment cost, excise duty, custom duty, sales-tax, freight and transit insurance, cost for civil engineering works, engineering, erection,project management, supervision, etc., contingency and interest during construction (IDC) should be included for the scheme selected.
• Payback period (PBP) is one of the measures for assessing the techno- economic viability of any project. The desired PBP formula is

 PBP = Total fixed capital expenses/(Net benefits / yr)