CERC restructures UI regime to enforce grid discipline

Written by fe Bureau | Mumbai | Updated: Mar 31 2009, 05:32am hrs
The Central Electricity Regulatory Commission (CERC) has notified new regulations on unscheduled interchange (UI) for electricity grid operations and also the amendments to Indian Electricity Grid Code (IEGC). Both these regulations will come into force from April 1. The main objectives of restructuring of the UI regime is to enforce grid discipline and to rationalise the UI rates for entities who abide by the specified grid operation parameters. Simultaneously, CERC has also narrowed down operational frequency range for the Indian Electricity Grid with the objective of improving the quality of supply. The entities overdrawing from the grid below the permissible frequency of 49.2 Hz will be required to pay additional UI charge.

Sending a clear message that UI is not a route for trading electricity, CERC in a release said it has for the first time specified limits for the overdrawal from the grid within the permissible operating range. This is in accordance with the philosophy that main purposes of UI are enforcing grid discipline and providing for settlement rates for unintended UI Interchanges. This step should force the distribution utilities to go for planned procurement of electricity and thereby creating environment for investors to set up new power plants. Presently, many utilities postpone setting of power projects and rely on overdrawal from the grid for meeting consumers demand.

UI rate vector has also been restructured. Now, there is a differential between the rates applicable to UI (overdrawal and under drawl as against the schedule) within the normal permissible limits and the rates applicable to those entities who resort to excessive overdrawal and endanger the grid security. In other words, UI regime now differentiates between a normal operator and an habitual overdrawing entity.

The permissible operating range for the grid has been narrowed down by 0.4 Hz. As against the earlier operating range of 49.0 Hz to 50.5 Hz, the new operating range will now be 49.2 Hz to 50.3 Hz. Prior to introduction of availability based tariff (ABT) regime in year 2002, the frequency in some of the regions such as Southern Region used to be as low as 48.0 Hz. resulting in burning of motors and sub-optimal operation of appliances.

The frequency band was then narrowed down from 49.0 Hz to 50.5 Hz. There was now a general feedback from the stakeholders that frequency band needed to be further tightened. The new tighter frequency band would lead to better quality of supply to the consumers. For example, the water pumps would run at speed closer to design speed and deliver higher output. The Commission intends to further review the operating range in near future.