Auxiliary power consumption reduction opportunities in thermal

power plants

By Lakshmi Narain

Auxiliary power consumption in a thermal power plant is a majorsource of energy consumption.

During the financial year 2007-08, total generation by coal plants was 488157.46 Mus with a PLF of 78.75 %.

Auxiliary power consumption was 8.17 % .

If this APC gets reduced only by 0.17 %, fresh capacity addition of about 120 MW can be achieved without any investment.

APC reduction initiatives not only reduces energy intensitybut also ensures more revenues because of increase in energy export.

APC REDUCTION OPPORTUNITIES

On line monitoring of power consumption of various auxiliaries through OLEMSMonitoring the power consumption of each equipment before and after overhaulEnergy efficient coating of the pumpsIntroduction of VFDsBetter O&M practicesConducting energy audit in a structured manner and implementation of recommendations as per action plan Introduction of latest state of the art technologies on specificsystems without waiting for R&M of the whole power plantCheck audits

On Line Energy Management System

As per CEA notification “Regulations on Installation and Operation of Meters –2006” meters for energy accounting and auditing are to be installed and monitored.

On Line Energy Management SystemTo measure, monitor, trend & compare power consumption of all major systems/ sub systems/ auxiliaries for improving Sp. Energy Consumption

Installation of energy meters on all HT drives and on LT drives > 100KW, which can be hooked up to a central server with the software for assessment of SEC

Already installed and working at Tanda, Dadri coal, Simhadri, Kawas, Faridabad of NTPC

Under procurement / installation at other stations

Monitoring the power consumption of each equipment before and after overhaul

This helps in assessing the power savings achieved due to maintenance jobs carried out during the overhaul and thus see the effectiveness of different maintenance job carried out.

Energy efficient coating of the pumps

4 -5 % improvement in pump efficiency is achievable.

Introduction of VFDs

Suitable for drives where i. load fluctuation are frequent ii. motor loading less than 60-70 % on various occasionsiii. equipments designed with margin for safety purposes

Depending the above factors, pay backs can be 2-7 yearsTechnology available for HT & LT applications, which has proven to be reliable. IGBT/IGCC already in use at Dahanu.

Better O&M practices

Conducting energy audit in a structured manner and implementation of action plan

Energy Audit System includesPreparation of Energy Audit Procedure

Preparation of Energy Audit Schedule

Conduct of Energy Audits

Preparations of Reports indicating recommendations, saving potential and action plan.

Implementation of the action plan including sustainability of energy savings.

Conducting energy audit in a structured manner and implementation of action plan

Check audit

The purpose of check audit is to assess the sustainability of the energy savings

Introduction of latest state of the art technologies on specific systems without waiting for R&M of the whole power plant