Electrical Energy Management & Auditing

Electrical energy is one of the major inputs for the economic development of any country. Since the major sources of energy are depleting at a rate faster than the rate at which they are replenished it becomes imperative that the usage of energy is managed efficiently for sustainable development of the country.
Further since modern technology is so dependent on energy it is necessary that all precautions are maintained towards the safe usage of energy also. Unsafe practices could lead to both loss of life and property.
The most important tool for efficient and safe use of energy is “information”, information on energy inputs, information on energy use, information on actual loaded capacity of equipment doing work etc. This brings us to the old adage “fore-warned is fore-armed”. A systematic and scientific approach to the collection of information and presentation of the same is called auditing. This has taken the following shapes in due course of time depending on the depth to which the final audit is required:
  • Detailed Energy Audit
  • Electrical Safety Audit
  • Power Quality Audit
  • Electrical Thermography
Subsequent to the collection of information a report is prepared bringing out the interpretations and recommendations to reduce the energy consumption of the facility. The Auditing program is a grand success only when the recommendations suggested and identified in the report shall be implemented on a time bound schedule and shall be closely monitored post implementation.

Detailed Energy Audit

The preliminary step for decision making in the area of efficient energy management is an Energy Audit. Energy Audit attempts to identify all the energy streams in a facility and map the energy usage. It attempts to balance the energy inputs to the use thus identifying or eliminating wastage in the process. The Energy Audit has been defined as “the verification, monitoring and analysis of the use of energy including submission of technical report containing recommendations for improving energy efficiency with cost benefit analysis and an action plan to reduce energy consumption”.
Thus the Detailed Energy Audit will bring out the efficiencies of all electrical energy consuming equipment based on the energy consumption. The Audit will bring out the inefficiencies in the power quality of the facility like harmonics, low power factor etc. It will bring out Energy Conservation measures (ECM) to efficiently use natural energy sources like solar energy for heating and lighting, geothermal energy for cooling etcexisting energy consuming equipment. Finally it will bring out the necessary tools to be used for monitoring efficient use of energy post implementation of energy saving measures.

For this purpose the information to be collected during the detailed energy audit includes:
  • Energy consumption by type of energy, by department, by major energy consuming equipment.
  • Energy cost and tariff data.
  • Process and material flow diagrams.
  • Generation and distribution of site services. (e.g. compressed air, steam)
  • Sources of energy supply.
  • Potential for fuel substitution, process modification etc.
  • Energy management programs and energy training programs.
  • Existing baseline information.

Scope of Energy Audit

The scope of the present audit was to carry out a detailed and comprehensive study of the electrical energy consumption and usage of Energy conservation methods were to be identified. Investment proposals required for implementation of the recommendations were to be brought out in the report along with the economic payback calculations.
For this purpose the following areas were studied in detail.

A. Electrical Distribution system

  • 1) Single line Diagram
  • 2) Cable loading
  • 3) Normal and emergency loads
  • 4) Electricity distribution in various areas and floors
  • 5) Study of reactive power management
  • 6) Options for power factor improvement
  • 7) Harmonics Study
  • 8) Current unbalance study
  • 9) Voltage unbalance study
  • 10) Exploring Energy Conservation Options

B. Lighting System

  • 1) Review of present Lighting systems
  • 2) Review of lighting Inventories
  • 3) Estimation of Lighting loads
  • 4) Comparison with acceptable standards
  • 5) Study of present lighting control system
  • 6) Exploring Energy Conservation Options

C. Review of other Heavy Electrical Equipment

  • 1) Other Miscellaneous Loads
  • 2) Exploring Energy Conservation Options

D. Energy Monitoring and Accounting System

  • 1) Present system of metering
  • 2) Present system of recording and data Logging
  • 3) Present system of periodic performance analysis
  • 4) Recommendations of effective energy monitoring

Energy Audit Limitations

  • Information obtained from the staff of the client is assumed to be true and accurate for the purposes.
  • The audits are based on Site inspection, detailed measurements & investigations only.
  • Measurements are done at the main control points assuming that all the points in the control circuit down the line are on.
  • Information obtained from other parties has been assumed true and accurate for the purposes.
  • No allowance is made to liaise with any other external consultants or agencies for further information.
  • No inspection within ceilings or other concealed spaces can be undertaken.
  • Reasonable assumptions with respect to name plate details of equipment have to be made in the absence of name plate and original design data.
  • The audit does not address any issues with local Building laws and bye-laws.
  • The inspection involves visual observations also since in many cases it is not possible to dismantle equipment for measurements.