Energy Conservation, Audit and Management
This domain tests whether you can find where energy is being wasted, measure it, and justify a fix with numbers - the daily work of an energy manager.
Audit types and instruments
A walk-through (preliminary) audit identifies obvious waste and quick wins in a day or two. A detailed audit instruments the plant, builds a mass-and-energy balance (Sankey diagram), benchmarks specific energy consumption (kWh per tonne, per unit output) and produces a bankable report. Typical instruments: power analyser, clamp meter, lux meter, infrared thermometer/thermal imager, anemometer, flue gas analyser and ultrasonic flow meter.
Where savings actually come from
- Motors and drives: right-sizing, VFDs on variable-load fans and pumps (affinity laws make this the biggest single source of savings).
- Power factor correction: capacitors reduce kVA demand and avoid utility penalties.
- Lighting: LED replacement, daylight and occupancy control.
- Thermal: insulation, condensate recovery, excess-air control in boilers, waste-heat recovery.
Worked example: capacitor sizing
A 100 kW load runs at 0.80 power factor. kVA = 100 ÷ 0.8 = 125, and reactive power = √(125² − 100²) = 75 kVAR. To raise PF to 0.95, new kVAR = 100 × tan(cos⁻¹ 0.95) = 100 × 0.329 = 32.9 kVAR. Capacitor required = 75 − 32.9 = 42.1 kVAR, so select the next standard 50 kVAR bank and check for over-compensation at light load.
Policy tools you should name
BEE star labelling, the PAT scheme for designated consumers, ECBC for buildings, energy audits by accredited energy auditors under the Energy Conservation Act 2001, and ISO 50001 energy management systems.
Traps
Treating energy conservation (switching off, cutting demand) as identical to energy efficiency (same service, less input); ignoring the utility's kVAh tariff while calculating capacitor savings; forgetting that load factor and PF penalties both appear on the bill; and proposing savings without a measurement baseline.