Execution phase of energy audit

The execution (audit) phase is the main working stage of an energy audit, where measurements are taken and energy-saving opportunities are found, after the pre-audit planning.

Steps in the execution phase

1. Detailed survey of each section: process, utilities (boilers, compressors, pumps, HVAC, lighting) and electrical distribution.
2. Measurements with portable instruments: power analyser (kW, kVA, pf, harmonics, load profile), clamp-on meters, lux meter, thermal imager, flue gas analyser, tachometer, flow, pressure and temperature meters.
3. Data analysis: load profiles, maximum demand, power factor, transformer and motor loading, losses.
4. Energy and material balance: quantify how much energy each area uses and how much is lost.
5. Specific energy consumption (e.g. kWh/ton) compared with benchmarks and past data.
6. Identify energy conservation opportunities (ECOs): pf correction, efficient motors, VFDs, lighting retrofits, air leak repair, insulation, heat recovery, load shifting.
7. Techno-economic evaluation: estimate savings, investment, payback period, NPV/IRR; rank as no-cost, low-cost and high-cost measures.
8. Discussion with plant staff to check that recommendations are practical and safe.

The output of this phase feeds the post-audit phase (report, implementation and monitoring).