电力书籍electric power generation—ch18.pdfVIP

18 BASIC STRUCTURE OF POWER MARKETING 18.1 RECONSTRUCTION OF THE ELECTRICITY BUSINESS The reconstruction has been proceeding stage-wise as below: Stage 1. Old vertically integrated electricity business had four sectors that operated in a follow-up sequence. These were generation transmission distribution customers. The main feature was a central office that covered every operation from planning to bill collections. The returns were fixed on the basis of reason- able returns on investment by an independent regulator. Stage 2. Competition was introduced in generation. Independent power producers (IPPs) were allowed to generate. There was only one central buyer, the old mo- nopoly. Stage 3. IPP’s were allowed to sell directly to large customers. It was compulsory for the monopoly to allow transmission and distribution over their networks for charges fixed by the regulator. Stage 4. Competition was opened up in distribution also. Distribution was section- alized into zones. These zones were either sold or leased to independent distribu- tors. These independents had the freedom to buy from a supplier of their choice. Open access to transmission as well as distribution was compulsory. Large cus- tomers traded independently. Electric Power Generation. By Digambar M. Tagare 351 Copyright © 2011 the Institute of Electrical and Electronics Engineers, Inc. 352 BASIC STRUCTURE OF POWER MARKETING Stage 5. Large customers were, step-wise, along with clusters of retail customers, now free to buy anywhere and use the networks for a charge, subject to opera- tional coordination. The electric supply started from generators and w