Energy Audit Lab (EX-705) - Unit 1 Short Notes

UNIT 1: FOUNDATIONS OF ENERGY AUDITING & LABORATORY ORIENTATION

1.1 Introduction to Energy and the Need for Auditing

1.1.1 Definition and Forms of Energy

• Energy: Capacity to do work. Measured in Joules (J).

• Key Forms:

  • Kinetic: Energy of motion ($$\displaystyle E_k = \frac{1}{2}mv^2 $$).

  • Potential: Stored energy due to position (gravitational: $$\displaystyle E_p = mgh $$).

  • Thermal (Heat): Internal energy from molecular motion.

  • Electrical: Energy from electric charge movement.

  • Chemical: Stored in molecular bonds (fuels, batteries).

  • Nuclear: From fission/fusion of atomic nuclei.

1.1.2 World & National Energy Scenario

• Global Trend: Rising consumption driven by industry, transport, and buildings. Fossil fuels (coal, oil, gas) dominate, causing emissions.

• India's Mix: Coal is primary for power. Growing renewables (solar, wind). High import dependence on oil & gas.

• Key Sectors: Industry (steel, cement), Transport, Residential/Commercial (HVAC, lighting).

1.1.3 Energy Crisis, Sustainability & Climate Change

• Crisis: Finite fossil fuels, price volatility, supply security issues.

• Sustainability: Meeting present needs without compromising future generations. Energy efficiency is a cornerstone.

• Climate Change: CO₂ emissions from energy use are the primary driver. Auditing reduces emissions.

1.1.4 Energy Efficiency vs. Conservation

1.1.5 Role of Energy Audit

• Industrial: Identify waste in motors, boilers, compressed air, process heating.

• Commercial: Optimize HVAC, lighting, office equipment in malls, offices.

• Residential: Improve insulation, appliance efficiency, lighting in homes.

1.2 Fundamentals of Energy Audit

1.2.1 Definition, Objectives & Scope

• Definition: Systematic examination of energy use, identification of energy flows, and quantification of savings opportunities.

• Objectives:

  1. Establish baseline energy consumption.

  2. Identify energy wastage & inefficiencies.

  3. Quantify potential savings (energy & cost).

  4. Recommend improvement measures (ECMs).

• Scope: Defines boundaries (e.g., entire plant, specific department, building systems).

1.2.2 Types of Energy Audits

1.2.3 Standard Audit Methodology & Phases

1. Pre-Audit: Planning, team formation, data request (bills, diagrams), site visit scheduling.

2. Audit: On-site measurements, data collection, system walk-through, interviews.

3. Post-Audit: Data analysis, report preparation, presentation of findings & recommendations.

1.2.4 Key Performance Indicators (KPIs)

• SEC (Specific Energy Consumption): Energy per unit of production/output.

$$ \text{SEC} = \frac{\text{Total Energy Input (kWh)}}{\text{Total Output (e.g., tonnes, units)}} \quad \boxed{\text{kWh/unit}} $$

• EI (Energy Intensity): Energy per unit area (for buildings).

$$ \text{EI} = \frac{\text{Annual Energy Use (kWh)}}{\text{Built-up Area (m²)}} \quad \boxed{\text{kWh/m²·yr}} $$

• EII (Energy Intensity Index): Normalized index comparing current to baseline (100 = baseline).

• Load Factor: $$\displaystyle \text{Load Factor} = \frac{\text{Average Load}}{\text{Peak Load}} $$ (0 to 1). Higher is better.

• Demand Factor: $$\displaystyle \text{Demand Factor} = \frac{\text{Maximum Demand}}{\text{Connected Load}} $$ (0 to 1).

1.2.5 Energy Management Standards: ISO 50001 Overview

• Purpose: Framework for systematic energy management, continual improvement.

• Core Principle: Plan-Do-Check-Act (PDCA) cycle.

• Key Requirements: Energy policy, energy review, baseline, energy targets, action plans, monitoring, internal audit, management review.

1.3 Energy Audit Team and Planning

1.3.1 Roles & Responsibilities

• Team Leader/Chief Auditor: Overall management, client liaison, report approval.

• Process/System Auditors: Experts in specific areas (electrical, thermal, HVAC).

• Measurement Technicians: Skilled in instrument operation and data collection.

• Data Analyst: Processes data, performs calculations, creates charts.

1.3.2 Audit Planning

• Define Boundaries: Physical (building, plant) and system boundaries.

• Set Goals: e.g., "Identify 15% savings potential in HVAC."

• Data Requirements: List of needed documents (P&ID, SLD, bills, maintenance logs).

1.3.3 Review of Historical Data

• Utility Bills (1-3 yrs): Analyze trends, seasonality, tariff structure, peak demand charges.

• Production Data: Correlate energy use with output for SEC calculation.

• Maintenance Records: Identify inefficient or faulty equipment history.

1.3.4 Understanding PFDs & SLDs

• PFD (Process Flow Diagram): Shows major equipment & material/energy flows in a process.

• SLD (Single Line Diagram): Electrical representation of power distribution system (source, transformers, feeders, major loads). Critical for electrical audits.

1.4 Laboratory Safety and Protocols

1.4.1 General Rules & Emergency

• Rules: No food/drink, wear PPE, know emergency exits, eyewash/shower locations.

• Emergency: Procedure for fire, electric shock, chemical spill. Know alarm sound & assembly point.

1.4.2 Safety in Electrical Measurements

• PPE: Insulated gloves, safety glasses, flame-resistant clothing.

• CAT Ratings: Critical! Use meters rated for the environment (CAT III for distribution panels, CAT IV for service entrance).

• Safe Handling: Inspect leads, use one hand rule, de-energize if possible (LOTO), never work alone on live circuits.

1.4.3 Safety in Thermal Measurements

• Hot Surfaces: Use heat-resistant gloves, allow equipment to cool before contact.

• Infrared Camera: Avoid direct sun on target, be aware of reflective surfaces, never point at sun or laser sources.

1.4.4 Lockout-Tagout (LOTO) Basics

• Purpose: Ensure equipment is de-energized and cannot be started during measurement.

• Steps: Isolate energy source, lock in "off" position, tag with name/date, verify zero energy state.

1.4.5 Data Integrity & Ethical Conduct

• Accuracy: Calibrated instruments, proper technique, no data fabrication.

• Ethics: Confidentiality of client data, honest reporting of findings (both positive & negative).

1.5 Basic Energy Calculations and Analysis

1.5.1 Units of Energy & Power

1.5.2 Conversion Between Units

• $$\displaystyle 1 \text{ kWh} = 3.6 \times 10^6 \text{ J} $$

• $$\displaystyle 1 \text{ BTU} = 1055 \text{ J} \approx 0.000293 \text{ kWh} $$

• $$\displaystyle 1 \text{ kcal} = 4184 \text{ J} $$

• $$\displaystyle 1 \text{ HP} = 0.746 \text{ kW} $$

1.5.3 Calculation from Meter Readings

$$ \text{Energy (kWh)} = \text{Meter Reading}_{\text{end}} - \text{Meter Reading}_{\text{start}} $$

1.5.4 Load, Demand & Diversity Factors

• Load Factor: $$\displaystyle \frac{\text{Avg. Load}}{\text{Peak Load}} $$. Indicates utilization.

• Demand Factor: $$\displaystyle \frac{\text{Max. Demand}}{\text{Connected Load}} $$. Indicates peak usage vs. total installed.

• Diversity Factor: $$\displaystyle \frac{\text{Sum of individual max. demands}}{\text{System max. demand}} $$. >1, indicates non-coincident peaks.

1.5.5 Simple Cost Calculation

$$ \text{Energy Cost} = \text{Energy Consumption (kWh)} \times \text{Tariff (₹/kWh)} \quad \boxed{} $$

1.6 Introduction to Energy Audit Tools & Instruments

1.6.1 Electrical Measurement Tools

1.6.2 Thermal Measurement Tools

1.6.3 Other Instrumentation

• Lux Meter: Measures illuminance (lux/foot-candle). For lighting audits.

• Sound Level Meter: Measures noise levels (dB). For HVAC/industrial noise surveys.

• Manometer: Measures pressure difference (Pa, in H₂O). For filter pressure drop, duct static pressure.

• Flow Meter: Measures fluid flow rate (steam, water, air). Types: ultrasonic, turbine, differential pressure.

1.6.4 Instrument Selection & Calibration

• Selection: Match instrument range & accuracy to task (e.g., clamp meter range > expected current).

• Calibration: Instruments must have valid calibration certificates. Accuracy degrades over time.

1.7 Data Collection and Documentation

1.7.1 Checklist Preparation

• Develop system-specific checklists (e.g., Lighting: lamp type, wattage, control, hours of use; Motors: HP, load, age, VFD presence).

1.7.2 Measurement Point Identification & Tagging

• Identify points on SLD/PFD (e.g., "MCC-1 Feeder-3").

• Tag physically (sticker) and in notes for clear reference.

1.7.3 Recording Data

• Field Sheets: Pre-formatted tables for systematic entry (Location, Parameter, Value, Unit, Time, Instrument ID).

• Logbooks/Digital Notes: Record observations, anomalies, operator comments.

1.7.4 Photographic Documentation

• Best Practices: Include scale/ruler in photo, note direction, capture context (equipment ID plate, overall system). Use before/after shots for proposed ECMs.

1.8 Introduction to Major Energy-Consuming Systems

1.8.1 Electrical Systems

• Motors: Major load. Efficiency classes (IE1, IE2, IE3, IE4). Losses: stator, rotor, core, friction.

• Drives (VFDs): Adjust motor speed → significant savings in variable load apps (pumps, fans).

• Transformers: Core (no-load) & copper (load) losses. Select high-efficiency (e.g., DOE 2016) units.

• Lighting: Lamp efficacy (lm/W), ballast losses. Shift to LEDs.

1.8.2 Thermal Systems

• Boilers/Furnaces: Efficiency = (Steam/Heat output) / (Fuel input). Losses: flue gas, incomplete combustion, radiation.

• Heat Exchangers: Fouling reduces effectiveness. Clean regularly.

• Steam Traps: Faulty traps waste steam. Survey with IR or ultrasonic.

• Insulation: Poor insulation causes heat loss. Check for damage, gaps, correct thickness.

1.8.3 HVAC Systems

• Chillers: Major energy user. Efficiency (COP/kW/ton). Check condenser/evaporator approach temps.

• AHUs/FCUs: Fan power, cooling/heating coils, filters.

• Cooling Towers: Approach temperature (cold water temp - wet bulb) indicates performance.

• Pumps: Similar to motors; affinity laws for variable speed.

1.8.4 Process-Specific Equipment

• Furnaces/Kilns: High-temperature processes. Focus on insulation, combustion, heat recovery.

• Compressed Air Systems: Very inefficient. Leaks are #1 waste. Check pressure, dryers, end-use.

1.9 Laboratory Session Structure & Report Formatting

1.9.1 Pre-Lab Briefing

• Objective: What will we measure/learn?

• Theory: Key principles (e.g., how a clamp meter works).

• Safety: Specific hazards & PPE for this experiment.

• Tools: List instruments to be used.

1.9.2 In-Lab Procedure

• Step-by-step: 1. Identify equipment, 2. Set instrument, 3. Take measurement, 4. Record data, 5. Repeat.

• Follow LOTO if required.

1.9.3 Post-Lab Data Processing

• Tabulation: Organize raw data in tables.

• Calculation: Apply formulas (e.g., kWh from kW & hours, SEC).

• Graph Plotting: Basic plots (e.g., load profile, energy vs. production).

1.9.4 Structure of a Lab Report

1. Title

2. Objective

3. Theory (Brief principles)

4. Apparatus (List of tools/instruments with models/range)

5. Procedure (Steps followed)

6. Observations (Raw data tables, photos)

7. Calculations (Show all steps, formulas, sample calc)

8. Results (Final tabulated values, graphs)

9. Discussion (Interpret results, errors, compare with standards/theory)

10. Conclusion (Summary of findings, whether objective met)

11. References (Textbooks, manuals, standards)

[!TIP] Exam Focus: Be prepared to define SEC, EI, audit types. Convert units (kWh to BTU). Identify correct instrument for a given measurement task (e.g., "Which tool for finding a steam trap leak?"). Explain safety steps before using a clamp meter on a live panel. Interpret a simple load factor value. Outline the PDCA cycle of ISO 50001.