One of my colleague yesterday (8/2) asked me what exactly an energy auditor do in energy audit project. It took a minute for me to answer that question because I did not involve directly into that project (I defined myself as expediter in this project, not as engineer. But since I am chemical engineer, I quite understand what we do in energy audit project). About that question, I said an energy auditor does calculation of energy consumption per product, determine if the plant consumes too much energy or not, and give some recommendations to conserve energy. Is that an easy job? I don’t think so. It is not easy, but it’s simple.
Energy audit in one plant and other plants can be different because each plant has different production process and the consequence, the equipments will be different. For example, in oil and gas gathering station, energy audit involve measurement of pump efficiency, compressor efficiency, pump electric motor efficiency, performance of genset, etc. I guess energy audit in cement industry, steel industry, or fertilizer industry would be very much different and more complicated. That’s why it is not easy.
The first step in energy audit is to understand the process in the plant and the equipments. It would be hard for someone to determine how much energy can be conserve if they don’t understand the whole process in the plant. This is very challenging step especially for young chemical engineer like me. But I believe the more I involve in the project, the more I understand many types of plant.
The second step in energy audit activity is to calculate how much energy required to produce a product. In this step, an energy audit needs to measure how much energy consumed by the equipments in the plant and how much produced. In this step, we will get energy consumption index (BTU energy/barrel oil, for example). We also can compare ECI with similar plant and make judgement if the process is efficient enough or not.
The third step is to determine the chance to conserve energy. Determining the energy conservation ideas perhaps is the most important activity in energy audit. An energy auditor should give the idea of how much energy can be conserved (in realistic way) and convert it into how much money we can save. The chance to conserve energy can be very simple, such as to regulate air flow in compressor so that the fuel will be burnt perfectly. It can be very costly, for example to install inverter in pump so that the energy consumption will follow pump load. Of course, there is a priority to follow.