Energy Audit

Energy Audit is an evaluation of the energy performance of a process, plant or a facility through analysis of the energy flows with an objective to reduce the overall energy consumption of the plant.

Drivers for Energy Audits:

  • Regulatory compliance requirements
  • Management review of performance
  • Technical due diligence of assets
  • Energy Cost Reduction

ACTSYS has NEA (Singapore National Environmental Agency) certified Energy Efficiency Opportunity Assessors (EEOA) for the various energy systems in Process Plants

ISO 50002 outlines the requirements and  steps involved in a standard Energy Audit

ACTSYS’ data analysis methodology, which involves first-principles based thermodynamic simulations, enables it to provide an accurate diagnosis of energy performance gaps in the plant against best performance levels / targets.

Best performance levels / targets can be established by:

  • Historical best performance data of the process units over a period of 12- 24 months
  • Tuned off-design models of equipment based on design / commissioning data to represent new-and-clean equipment performance
  • Optimised operational parameters obtained from simulation models and test runs

A 3-step approach to identifying opportunities
for Energy Performance Improvement

Identification of energy improvement opportunities is a 3-step process – starting off with the ‘low hanging fruits’ – Operational Adjustments and Corrective Maintenance.


This is followed by retrofit improvement opportunities which is more involved as it requires basic engineering and vendor quotations for cost estimation of capital expenditure. BAT Best Available Technology in areas such as high efficiency heat exchangers, low level heat driven absorption chillers, structured packing for distillation columns, high efficiency compressor impellers, vapour recompression heat pumps, etc will be investigated for such retrofit improvement opportunities.

Typical areas in a Process Plant requiring Operational Adjustments or Corrective Maintenance


Deliverables will be a detailed energy audit report that includes:

  • Quantification of Energy Efficiency Performance of all significant energy users within the agreed Energy Audit boundary
  • Quantified energy-cost savings for the identified energy efficiency improvement opportunities – these will include achievable savings through operational adjustments, corrective maintenance and improvement retrofits
  • Techno-commercial feasibility analysis with ±30% – 50% cost estimates of the proposed retrofit options