Baseline service level adjustment methodologies for energy efficiency projects on compressed air systems in the mining industry

Compressed air systems used in the mining industry mainly supply compressed air to the underground operations of the mine. Underground pneumatic instrumentation is critical to the operation and production of the mine. They ensure that the mine can sustain a high level of productivity as well as safety. The air is compressed, using multi stage industrial size compressors, and then transported to the underground operations via a complex piping network. Without the proper maintenance of a complex compressed air network the operational efficiency of the system decreases drastically over time. Some of the Energy Service Companies (ESCo) in South Africa have been able to very effectively address inefficient compressed air systems over the past few years. To properly quantify the savings achieved by any project, independent Measurement and Verification (M&V) needs to be done. The most critical step in evaluating any energy efficiency intervention would be to establish a baseline for the system under consideration. Firstly the boundary of the system will need to be clearly defined. Once the boundary of the system has been established, it will need to be decided under which to the four options listed in the IPMVP the project will be evaluated. According to the boundary and the IPMVP option of the system a project specific baseline methodology will need to be developed. As part of the baseline methodology the Service Level Adjustment (SLA) methodology will need to be established. It is with the development of the service level adjustment model where the biggest challenge presents itself with compressed air energy efficiency projects. This paper will address some of the SLA methodologies that have been used for the evaluation of a number of compressed air projects, and comment on the effectiveness and applicability of each.