--- title: "Energy audit definition and process" subject: "Industrial Power Distribution and Illumination" chapter: 10 key: "semester_6/industrial_power_distribution_and_illumination:define-energy-audit-process" source: https://www.bctengineer.com/q/semester_6/industrial_power_distribution_and_illumination/define-energy-audit-process site: BCT Engineering --- # Energy audit definition and process Industrial Power Distribution and Illumination · Chapter 10: Electrical Energy Audit in Industry - Asked in: 2080 Chaitra, 2+6 marks - Video: [Energy Audit - Need for Energy Audit - Types of Energy Audit](https://www.youtube.com/watch?v=OsJ-j1LHTHk) — Energy Insight Hub (EIH) - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_6/industrial_power_distribution_and_illumination/define-energy-audit-process - Whole chapter: https://www.bctengineer.com/md/semester_6/industrial_power_distribution_and_illumination/chapter-10 ## Question Define Energy Audit. Explain the process of carrying out energy audits in an industry. ## Answer #### Energy audit **Energy audit** is the verification, monitoring and analysis of energy use in a plant, including submission of a technical report with recommendations for improving energy efficiency, together with cost-benefit analysis and an action plan to reduce energy consumption. #### Process of carrying out an energy audit **Phase I – Pre-audit (planning)** 1. Meet top management; decide scope, objectives, budget and time. 2. Form the audit team (electrical, mechanical, process staff). 3. Collect historical data: electricity and fuel bills (1–3 years), production data, single-line diagram, list of equipment with ratings. 4. **Walk-through survey** to understand the process and identify major energy users and obvious wastes. 5. Plan measurements and arrange instruments. **Phase II – Audit (execution)** 6. **Detailed measurements:** power analyser (kW, kVA, pf, harmonics), clamp meters, lux meter, thermal camera, flue gas analyser, flow/pressure/temperature meters, ultrasonic leak detector. 7. **Energy and material balance:** find how much energy each section and equipment uses and the losses. 8. Compute **specific energy consumption** (kWh per unit product) and compare with benchmarks. 9. **Identify energy conservation opportunities (ECOs):** pf correction, efficient motors, VFDs, LED lighting, leak repair, waste heat recovery, load management. 10. **Techno-economic analysis** of each ECO: annual savings, investment, simple payback = investment/annual saving, NPV or IRR. **Phase III – Post-audit (implementation & follow-up)** 11. Prepare the audit report: summary, present consumption, ECOs ranked as no-cost / low-cost / high-investment, action plan. 12. Present to management, implement selected measures. 13. **Monitor and verify savings** (M&V) and repeat the audit periodically. ```text Pre-audit ──► Walk-through ──► Measurement │ │ ▼ ▼ Report ◄── Cost-benefit ◄── Energy balance & ECOs │ └──► Implementation ──► Monitoring & verification ``` ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. Which best defines energy audit? A. Verification, monitoring and analysis of energy use with a technical report on recommendations, cost-benefit analysis and action plan B. Measuring only the electricity bill C. Replacing old motors D. Installing a DG set Answer: A. An audit includes analysis plus a report with ECOs and an action plan. (Key point: Definition) 2. What is the correct order of the three audit phases? A. Post-audit, audit, pre-audit B. Audit, pre-audit, post-audit C. Pre-audit, audit, post-audit D. Audit, post-audit, pre-audit Answer: C. Planning (pre-audit) comes first, then measurement (audit), then report and follow-up (post-audit). (Key point: Audit phases) 3. What is specific energy consumption used for? A. Calculating payback B. Comparing energy use per unit of product (kWh per unit) with benchmarks C. Measuring the power factor D. Setting the tariff Answer: B. SEC shows how efficiently energy is turned into product, compared with benchmarks. (Key point: Specific energy consumption) 4. What happens in the post-audit phase? A. Walk-through survey B. Detailed measurement C. Data collection of bills D. Report with ranked ECOs, implementation, and monitoring and verification of savings Answer: D. The post-audit phase delivers the report, implements measures and verifies savings. 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