M. Kleingeld

A performance-centred maintenance strategy for industrial DSM projects

Underperformance of industrial DSM projects is often caused by a lack of proper maintenance practices. This results in wasted electricity cost-savings opportunities and an increased demand for electricity on the national grid. A solution to the problem of underperforming industrial DSM projects is to apply a performance-centered maintenance (PCM) strategy. The various aspects of the PCM strategy are presented in this paper. It is based on the plan-do-check-act (PDCA) cycle for continuous improvement, which also forms part of the ISO 50001 energy management standard. Results show that the application of the PCM strategy could result in a performance increase of up to 70% when applied to underperforming industrial DSM projects. This proves the value of the PCM strategy to maximise and sustain the performance of industrial DSM projects.

Modernising underground compressed air DSM projects to reduce operating costs

Compressed air is an energy intensive utility that is frequently used in the deep level mining industry. Most compressed air networks are designed to ensure ample compressed air supply to consumers. This has created the foundation for existing compressed air energy saving projects on deep level mines. Over the past decade, electricity costs in South Africa increased drastically. As a result, the need to further improve and optimise existing Demand Side Management (DSM) projects with modern technology and expertise has become more feasible. This study therefore provides and evaluates a solution to reduce the electricity consumption and operating costs of a compressed air system on a deep level mine. This was achieved by modernising and improving an existing underground compressed air DSM project. It was found that the improvements realised significant additional electrical energy savings. This resulted in ample cost savings to justify the implementation of the improvements.

Analysing the effect of DSM projects at South African cement factories

In any developing country an increasingly higher demand for electricity supply exists. South Africa experienced load shedding during 2007/2008 and again in 2014 due to a supply shortfall. Demand Side Management (DSM) is a short-term solution to stabilise the national grid by managing the electricity demand on the consumers side. DSM aims to reduce the electricity consumption with immediate results in the short-term.

Photovoltaic cells - the hot new investment?

A combination of factors, including recent decreases in the cost of photovoltaic cells and batteries as well as the governments Renewable Energy Independent Power Producer Procurement Program, have recently made investment in Solar Photovoltaic energy facilities more appealing.

Failure Prediction of Mine De-watering Pumps

Abstract The de-watering reticulation system of a deep level mine requires a network of pumps to pump water from underground to the surface. These de-watering pumps are exposed to extreme operating conditions, which can result in unacceptably short service lives. It is thus important for mining personnel to use the available tools to improve system operations and maintenance procedures. Current maintenance strategies involve reactive and preventive models, which can lead to failure creep. In order to implement proactive strategies, forecasting models are required. One of such models can be Weibull models, which has proven to be successful for many product failure mechanisms. The Weibull models have been used extensively in the reliability-engineering environment, but have not yet been implemented on a de-watering pump operating in extreme conditions on a deep level mine. A new practical method for predicting pump failure using various Weibull distribution functions was thus developed. The methodology was validated on four pumps, and it was found that the failures of new pumps were successfully predicted based on the Weibull analysis of previously failed pumps. It was also found that a quadratic relationship exists between the characteristic life of a de-watering pump and the operating depth underground. This is significant because all of the factors affecting the service life of a de-watering pump are quantified regarding only the operating depth and the characteristic life.

Improving mine compressed air network efficiency through demand and supply control

The platinum price has decreased nearly 42% since 2010, forcing platinum mines to reduce expenses in order to remain profitable. Electricity consumption is a large capital expenditure for the mining sector and efforts should thus be made to reduce energy consumption while maintaining production. Compressed air networks were identified as a large energy consuming section in the mining industry. Inefficiencies in these networks were thus investigated, with focus given to the compressors, the pipelines transferring compressed air and the compressed air consumers. A strategy was then developed in order to ensure that the compressed air consumers will not receive insufficient pressure or flow. This strategy also includes a reduction in energy consumption of the compressed air network. Finally this strategy was tested on a mine and savings were calculated. These savings include daily energy savings of 18.9 MWh which result in annual cost savings of R15.7 million.

Improving DSM project implementation and sustainability through ISO standards

Energy service companies (ESCos) have been assisting Eskom, South Africas leading electricity utility, in implementing and managing energy projects around the country. However, the need for a sustainable energy management system (EnMS) within the Demand Side Management (DSM) projects does exist. An EnMS was designed to achieve the maximum possible energy savings performance on these projects. Three relevant International Organization for Standardization (ISO) standards were integrated into the development and implementation of this system. It provides a framework for project engineers and industrial clients to apply before, during and after project implementation. The Plan-Do-Check-Act (PDCA) cycle was applied throughout this article and follows the basic steps recommended by the relevant ISO standards. This cycle emphasises the concept of continual improvement. This article illustrates that the continual improvement of an ISO based EnMS will result in a sustainable increase in electricity savings. An overall increase in project quality can thus be defined and measured according to the electricity consumptions and electricity cost savings. The proposed EnMS was thus implemented and studied on five mines. The electricity cost savings from the selected projects resulted to nearly Rl8-million during project implementation. The EnMS therefore indicates that a continually controlled framework can improve the quality of DSM project implementation and sustainability. With the flexibility of changing the system according to impulsive constraints and client demands, the system can be used with various DSM projects.

A holistic approach to presenting DSM project results

A slight variance in dataset quality or baseline model accuracy can affect the level of confidence at which DSM project results are calculated. General measurement and verification (M&V) guidelines mitigate this inherent variance by reporting a conservative result. However, it remains important to quantify the magnitude of variance to ensure that the conservative approach does not adversely affect any of the stakeholders involved. A critical analysis of published literature relating to the M&V of DSM projects highlights a strong tendency towards presenting project impact at a high level of accuracy. Published results are generally presented without interpretation and therefore do not objectively convey the true nature of system performance. The analysis also identified a lack of long-term evaluation techniques which can be applied to continuously monitor project performance. This prompts the development of a holistic approach to presenting DSM project results. This paper utilises graphical presentation to clearly convey project performance characteristics. The methodologies presented in the paper are applied to several industrial DSM case studies in order to verify the practical application in real life scenarios. The results highlight previously unknown characteristics which can significantly influence how stakeholders perceive project success. The results are further validated by comparing case study results to results obtained from independent 3rd parties.