What does an on-site inspection look like during an audit?

An on-site inspection is a scheduled visit by an engineering or audit team to an industrial facility. Its purpose is to directly understand how the facility operates – the course of technological processes, the layout of energy installations, and the characteristics of media consumption. This stage allows auditors to go from document analysis to real-world understanding of how the plant operates – and thus, by analyzing and understanding the company’s energy management, enables identification of areas with the greatest savings potential.

In the case of company energy audits (mandatory for large companies under the Energy Efficiency Act) and Walk Through audits (quick energy reviews), the on-site inspection is the foundation for further analysis. It also helps define the scope of necessary measurements, collect input data for energy efficiency improvement models, verify modernization potential, and plan further audit, conceptual, or investment activities.

An on-site inspection usually consists of two or three stages. Although each facility may require an individual approach, some elements remain constant regardless of the industry or scale of the plant. Immediately after receiving the assignment, a list of basic data is sent to the company, necessary to understand the energy structure of the enterprise and to prepare the opening meeting.

Opening meeting

The first step in the collaboration is usually a meeting between the audit team and the plant’s representatives – typically those responsible for business strategy, environmental strategy, maintenance, energy use, automation, or technical infrastructure. The meeting aims to mutually introduce both teams and discuss:

• the company’s strategy and audit goals,
• the plant’s characteristics and technological processes,
• main energy consumers,
• types of media used (electricity, gas, steam, compressed air, etc.),
• existing energy monitoring systems,
• plant development plans (e.g. modernization, expansion, new production lines).

This conversation enables building a basic energy flow diagram, understanding how energy is used in key technological processes, defining the scope of further actions, planning the walk through the facility, and identifying areas that require special attention.

Walk through the facility

The second part of the inspection is a walk through the facility – often starting from energy sources/raw material supplies, through utility distribution networks, to production, packaging, storage, and distribution. The engineering team walks through boiler rooms, compressor stations, main transformer stations, cooling and gas machine rooms, pipelines and collectors, production processes, key heat and cold extraction points, energy recovery installations, ventilation systems, and lighting. The analysis includes, among others:

• main and auxiliary technological processes in terms of energy intensity,
• sources and points of energy loss,
• operation and technical condition of energy equipment,
• control logic and optimization potential of the installations,
• waste energy utilization (if applicable),
• availability of measurement data and energy monitoring.

This type of walkthrough allows theoretical assumptions to be verified and the analysis adapted to the real operating conditions of the facility.

Closing meeting

An optional but very helpful part of the inspection is a brief closing meeting. It takes place after the walkthrough and allows preliminary observations to be discussed, any doubts clarified, and next steps defined – e.g. the scope of required measurements, additional documents needed to verify findings, or a plan for further contact.

A successful on-site inspection requires the presence of people who know the facility and its operations well. On the company side, the following typically participate in meetings and walkthroughs:

• maintenance department representatives,
• persons responsible for energy media consumption,
• process engineers,
• energy efficiency specialists (if present in the company structure),
• technical department managers.

This way, the audit team gains access to practical knowledge, can quickly clarify any doubts, and obtain technical information necessary for further analysis.

The on-site inspection allows the identification of energy losses – whether due to leaks, lack of insulation, or technological losses occurring during the process. Auditors also examine potential sources of waste energy and ways to utilize them. The technical condition and operation of equipment are important – not only main units, but also auxiliary ones such as pumps, fans, compressors, boilers, chillers, generators, or transformer stations.

Engineers also analyze how energy media are managed – how they are distributed across the facility, how their consumption is monitored, and whether measurement data are available to verify the energy intensity of specific production lines. The audit team assesses whether energy monitoring systems enable anomaly detection and consumption optimization, or whether they rely solely on general aggregate meter readings. Operating conditions are equally important – including how systems operate in different modes (full load, night shifts, weekends, downtimes), equipment rotation, and daily energy management practices by technical personnel.

In the case of a Walk Through audit, the on-site inspection has a more general character – its purpose is to identify a long list of potential tasks, from low-cost improvements (so-called quick wins) to large-scale investment solutions. Based on this list, the most suitable direction is chosen, matching the plant’s strategy and needs. The choice of actions is often influenced by financial capabilities or implementation feasibility – e.g. due to available technological downtimes or delivery schedules. Such alignment with company goals often sheds new light on many investment ideas that can be implemented efficiently but may not be obvious at first.

The on-site inspection is an important part of an energy audit. It allows auditors to understand how energy is actually used in the plant and where the largest losses occur. It’s also a key moment for laying the foundation for further cooperation – based on technical knowledge and direct contact with the plant’s team. Through conversation during the inspection, both sides can clarify expectations and address any concerns. It’s also a great opportunity to get to know the expectations of the team operating the processes daily – these people often spot the first signs of potential energy efficiency improvements. The auditor’s role is to analyze that potential and describe the actions not only through calculations and charts but also by indicating whether such a project is economically viable for the company.