EX-703-B Energy Audit and Management - Jun 2025 Question Paper

Under each question, How to answer lists the points an answer should cover, outlined by CampusPrep from the syllabus. Check the details against your textbook.

1. 7 Marks
   aWhat are the environmental aspects of energy consumption? Also discuss about the environmental aspects of renewable energy sources.
   How to answer

   • Define energy consumption and its environmental impacts (air pollution, GHG, acid rain, thermal pollution).
   • Discuss impacts of conventional sources: coal, oil, gas.
   • Discuss environmental aspects of renewable sources: solar, wind, hydro, biomass, geothermal.
   • Mitigation and sustainable consumption measures.
2. 7 Marks
   bWhat do you understand by Energy Auditing? Describe the various types of energy auditing.
   How to answer

   • Define energy auditing - systematic inspection and analysis of energy flows.
   • Objectives and need of energy audit.
   • Describe types: preliminary/walk-through, targeted, detailed/comprehensive, investment-grade.
   • Brief procedure for each type.
3. 7 Marks
   aWhat are the managerial functions involved in energy management? Suppose you are an energy manager in an institutional organization. Explain the steps for energy auditing and energy management in an institutional organization.
   How to answer

   • List managerial functions: planning, organizing, staffing, directing, controlling.
   • Role of energy manager in institutional organization.
   • Steps for energy auditing: data collection, analysis, recommendations.
   • Steps for energy management: monitoring, targeting, implementation.
4. 7 Marks
   bDuring April-2023, the university has recorded a maximum demand of 800 kVA and average PF (power factor) is observed to be 0.80 lag, the minimum average PF to be maintained is 0.90 lag as per the independent utility supplier and every one % dip in PF attracts a penalty of Rs 20,000/in each month.

   1. i)Calculate the improvement in PF for May-2023 by installing 100kVAr capacitors.
   2. ii)Calculate penalty to be paid if any during May-2023.
   How to answer

   • Compute initial kW, kVAr from 800 kVA at 0.80 pf.
   • Subtract 100 kVAr compensation to get new kVAr and new pf.
   • Compare new pf with 0.90 requirement to find % dip.
   • Calculate penalty at Rs 20,000 per 1% dip per month.
5. 7 Marks
   aHow an "energy efficient motor" is different from a "standard motor" in construction aspects? What are the advantages of energy efficient motor on standard motor?
   How to answer

   • Construction differences: lamination, copper losses, fan, air-gap, design.
   • Loss reduction features in energy efficient motor.
   • Advantages: higher efficiency, lower losses, payback, reliability.
   • Comparison table standard vs energy efficient motor.
6. 7 Marks
   bA 20 kW motor has full load efficiency of 90%. Input at part loading is 440 V and 10 A. The power factor is 0.78. Find the motor loading in percentage.
   How to answer

   • Calculate 3-phase input power $P_{in}=\sqrt{3}VI\cos\phi$.
   • Estimate output power using full-load efficiency or loading relation.
   • Compute % loading = output / rated 20 kW x 100.
   • State result in percentage.
7. 7 Marks
   aWhat are the major problems due to harmonics? Describe what are the few equipment's, which contribute to harmonics in the utility. Explain how and why do this happen.
   How to answer

   • Define harmonics and THD, sources: rectifiers, VFDs, computers.
   • Major problems: overheating, neutral overloading, resonance, metering error.
   • How and why non-linear loads generate harmonics.
   • Mitigation overview.
8. 7 Marks
   bExplain the working of Thermic fluid heating system and why it is preferred to steam heating in some cases?
   How to answer

   • Working principle of thermic fluid heating system with circuit.
   • Components: heater, expansion tank, pump, user.
   • Advantages over steam: high temperature at low pressure, no corrosion.
   • Applications where preferred.
9. 7 Marks
   aTwo identical biomass fired boilers of capacity 15 TPH are operated in a chemical industry. They each have a full load efficiency of 82%. The part load efficiencies at 75% and 45% load are 78% and 66% respectively. For meeting 20 TPH requirement of steam, would you prefer to run both the boilers at 10 TPH capacity or one at full load capacity and other at 50% capacity. Estimate the % savings in the preferred case.
   How to answer

   • Calculate fuel requirement for both boilers at 10 TPH vs 15+7.5 TPH using efficiencies.
   • Compare total fuel consumption of two operating options.
   • Select preferred case with lower fuel use.
   • Estimate % savings = difference / higher x 100.
10. 7 Marks
    bDescribe the working of a steam traps and its performance assessment methods.
    How to answer

    • Define steam trap and its function to remove condensate.
    • Types: mechanical, thermostatic, thermodynamic - working.
    • Performance assessment: visual, thermal, ultrasonic methods.
    • Energy loss due to faulty traps.
11. 7 Marks
    aWhat is the significance of parallel operation in case of centrifugal pumps? Describe the factors affecting performance and energy efficiency of refrigeration plants.
    How to answer

    • Significance of parallel operation of centrifugal pumps for variable demand.
    • Operating point and efficiency with parallel pumps.
    • Factors affecting refrigeration plant performance: evaporator/condenser pressure, superheating.
    • Energy efficiency measures in refrigeration.
12. 7 Marks
    bWhat is Life Cycle Costing? Also explain the process, applications and effects of life cycle costing.
    How to answer

    • Define life cycle costing (LCC) and its need.
    • Process steps: acquisition, operation, maintenance, disposal costing.
    • Applications in equipment selection and energy projects.
    • Effects on decision making and total cost.
13. 7 Marks
    aWhat is "Payback Period" and what is the significance of Risk Analysis in evaluating it?
    How to answer

    • Define payback period - time to recover initial investment.
    • Types: simple and discounted payback.
    • Significance of risk analysis: sensitivity, uncertainty.
    • Role in project evaluation.
14. 7 Marks
    bABB company decided to replace 500 W lamp with 350 W lamp, 350 W lamp with 150 W lamp and 125 W lamp with 60 W lamps for same light output for 4500 hours of annual operation and consider Rs. 5.5 as per unit cost. Calculate energy savings, cost savings and simple payback period due to investment decision.
    How to answer

    • Compute wattage saved per lamp replacement (150W, 200W, 65W).
    • Calculate annual energy savings for 4500 hours operation.
    • Calculate cost savings at Rs 5.5 per unit.
    • Estimate simple payback period from investment vs savings.
15. 14 Marks
    Write short notes on: (any Two):

    1. a)Manners and intervals of time for conduct of energy audit as per Bureau of Energy Efficiency (BEE) regulations.
    2. b)Steam distribution systems.
    3. c)LED lighting and scope of energy conservation in lighting.
    4. d)Internal rate of return.
    How to answer

    • Select any two topics from a-d.
    • Give definition, relevant BEE provisions / technical details.
    • Explain energy conservation scope and benefits.
    • Conclude with applications.