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5. Sustainability framework
5.7. Sustainability framework
Data is acquired from three different sources, namely, the clients’ Eskom accounts, the mines SCADA system and data that must be manually added to the database by the mine. It is important to ensure the integrity of the data, which is complicated by the reliance on the client’s data management provider. Working in collaboration with this provider allows consistent data availability and uploading and retrieval of the latest data.
Using this information, potential project sites for energy savings can be highlighted by monitoring key operational indicators. The sustainability framework starts by identifying the large energy-consuming sites of a mining company using a holistic approach to the company’s electricity consumption. An overview dashboard of these processes is shown in Figure 62.
Figure 62: Energy usage per mine
HG Brand 2013 144 With each mine’s individual electricity consumption and the total consumption known, a budget is assigned to the electricity usage. The baseline electricity consumption is compared to the present year’s electricity consumption. A budget is assigned for compliance to the ISO 50001 standard and can be seen in Figure 63.
Figure 63: Electricity consumption budget
The electricity cost saving achieved by these projects can be quantified by the ESCO. These project savings can be seen in Figure 64.
Figure 64: Project electricity costs savings
Knowing the savings achieved by each individual project allows the carbon dioxide-reduction potential to be quantified. The carbon credit potential can be seen in Figure 65. In conjunction, there is also the risk of carbon tax that can be levied on Eskom for carbon
HG Brand 2013 145 dioxide production. This will inevitably be transferred to the client and creates a financial risk to high electricity-consuming clients. This risk is quantified in Figure 66.
Figure 65: Carbon credits from two electricity-reduction projects
Figure 66: Carbon tax risk quantification
This sustainability framework allows the monitoring of current project performance on a monthly and weekly basis. The monthly monitoring of these projects can be seen in Figure 67.
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Figure 67: Monthly project monitoring
In Figure 67 it can be seen that each project is monitored individually. Grey blocks indicate months where no data was received or the project was still in the implementation phase.
Green blocks indicate months where data was received and the project target was achieved.
Red blocks indicate months where data was received but the project did not achieve its electricity-savings target. The weekly project monitoring can be seen in Figure 68.
Figure 68: Weekly project monitoring
In Figure 68 the red, green and grey blocks again represent the same conditions as in Figure 67. However this is done on a daily basis. The orange blocks represent days that something hampered the project performance which was out of the ESCO’s control. These are known as condonable days. In Figure 69 it is shown how project performance is monitored in the long term.
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Figure 69: Cumulative target tracking
This allows the cumulative performance of a project to be compared to what the total savings should have been. This is very important as some projects have seasonal effects. An example of such a project is the CA project. In the winter the atmospheric temperatures are lower, which allows for larger savings on the BAC water supply.
Each project’s performance can be monitored individually. This helps SANEDI with the project performance analyses. Project monitoring aids the ESCO with project performance tracking and also allows maintenance to be done on the projects. It will eventually also help quantify the carbon tax that must be paid to Eskom.
In Figure 70 the load shift performance achieved by a pumping project can be seen. In Figure 71 the energy-efficiency performance of a WSO project is shown, compared to the energy- efficiency performance of a CA project, in Figure 72, and the same of an OAN project, in Figure 73.
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Figure 70: Pumping project savings monitoring
Figure 71: WSO project savings monitoring
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Figure 72 CA project savings monitoring
Figure 73: OAN project savings monitoring
HG Brand 2013 150 In each figure, the blue line represents the baseline for each project. Factors like increased production do however alter what the current baseline should be. For this reason, the original project baseline is scaled to match the changing conditions. This scaled baseline is shown in turquoise. The actual electricity-consumption profile is then shown in green. It can clearly be seen that the WSO and CA projects are energy-efficiency projects. The pumping project is a load shift project and this OAN project example is of a peak clip project.
To comply with the ISO 50001 standard, documentation for each step of the plan-do-check- act phases must be generated. This sustainability framework aids the mine in generating these documents and shows the progress of each phase. Standard answers are required from the user, which allows the automatic generation of reports. The documentation required for each step is shown in Figure 74, Figure 75, Figure 76 and Figure 77.
Figure 74: Documentation for the plan phase
Figure 75: Documentation for the do phase
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Figure 76: Documentation for the check phase.
Figure 77: Documentation for the act phase
It can be seen that the sustainability framework aids the mine in achieving ISO accreditation.
It also allows the identification of project potential and monitors the required project performance. Examples of the reports that are generated by the framework are shown in Appendix D.