An energy audit is one of the most important tools enabling businesses to manage energy effectively and optimise operating costs. In this article, we explain the step-by-step procedure for an Enterprise Energy Audit. Learn what to expect at each stage and how to prepare properly for the entire process.
Formal requirements and the legal context of an energy audit
An Enterprise Energy Audit is a comprehensive analytical procedure designed to provide a detailed review of a company’s energy consumption, covering at least 90% of its total energy demand. In Poland, the process is governed by the Energy Efficiency Act and EED Directive 2012/27/EU and is based on current, measurable data on the consumption of electricity, heat, cooling and fuels in buildings, industrial installations and transport.
In Poland, large enterprises are required to carry out an audit if they meet at least one of the following conditions*: they employ more than 250 people, or their annual turnover exceeds EUR 50 million and their balance-sheet total exceeds EUR 43 million. The audit should be repeated every 4 years and meet the requirements of PN-EN 16247. Companies that are not subject to the audit obligation may carry it out voluntarily.
Audit preparation and planning
The actual Enterprise Energy Audit process begins with a preparatory stage during which:
- the scope of work is defined and the main audit objectives and areas are identified, e.g. the entire enterprise, production lines, administrative buildings and auxiliary systems to be analysed;
- preliminary technical documentation, installation diagrams, equipment specifications, utility bills and measurement data from the previous 12–36 months are collected;
- the auditor establishes basic information about the site structure, types of technological processes and energy consumption in individual areas;
- an audit plan is prepared, including a schedule of site visits and analyses.
This stage also includes identifying meters and SCADA, BMS or ERP systems from which data can be obtained.
Data analysis and site visit
The next stage of the audit is a detailed analysis of operating and measurement data. The auditor analyses data from the previous 12-36 months on electricity, heat, gas, process steam and fuel consumption. These data are compared with production data to determine energy performance indicators (e.g. kWh/unit of product). The analysis also considers load profiles, consumption charts, peak demand and the technical parameters of equipment.
Based on the data collected, a site visit is planned, during which activities include:
- review of technical documentation for equipment and installations, as well as observation and measurement of technological and transport processes;
- checking the technical condition and operating parameters of boilers, turbines, compressors and air-conditioning systems;
- measurement and analysis of energy parameters;
- verification of control algorithms and operating schedules;
- assessment of insulation condition and heat losses;
- lighting audit (illuminance, type of luminaires, controls);
- identification of leaks and points of leakage in utility systems.
After this phase, the auditor has a complete technical and energy profile of the enterprise, making it possible to identify areas requiring intervention.
Energy consumption modelling and identification of savings opportunities
After the site visit comes the calculation phase, which includes energy consumption modelling and evaluation of installation efficiency. Energy balances, Sankey diagrams and energy loss maps are prepared. Based on the calculations, specific energy-saving measures are identified. These may include:
- modernisation of drive systems (motors, variable-speed drives),
- optimisation of compressed air systems,
- waste heat recovery from technological processes,
- energy renovation of buildings,
- lighting upgrades,
- implementation of weather-compensated controls and equipment operating schedules,
- changes to energy purchasing tariffs and contracted capacity management.
Each recommended solution is analysed in terms of investment costs, resulting savings and payback period (simple payback time). The economic viability of the measures is presented by comparing scenarios before and after implementation.
Report preparation and compliance with statutory requirements
The final stage is the preparation of a comprehensive Enterprise Energy Audit report. The report includes a description of the enterprise, the energy consumption balance, a list of recommended improvements, an analysis of energy and economic effects, and appendices containing measurement results, technical drawings and calculations. In Poland, the report must comply with the Energy Efficiency Act and include calculations confirming potential energy savings, expressed in MWh or TJ. The enterprise must retain the audit data for 5 years and notify the President of the Energy Regulatory Office (URE) that the audit has been completed within 30 days of completion. The report may also serve as a basis for applying for energy efficiency certificates (so-called White Certificates), providing an additional form of financial support for investments.
* From 2026, the regulations on company energy audits will change. Instead of company size, the criterion for a mandatory audit will be annual final energy consumption. Companies consuming more than 2778 MWh (10 TJ) per year will have to conduct an audit every 4 years, while companies consuming more than 23611 MWh (85 TJ) will additionally have to implement an ISO 50001 energy management system.
