Identifying demand market participation opportunities available in cement plants

Abstract

South African cement manufacturers are under financial pressure. Sales have declined due to the 2008 recession and electricity costs have tripled from 2005 to 2012. Electricity cost savings are therefore more important than ever. Unfortunately retrofitting highly energyefficient equipment is not ideal. These installations are costly and take a long time to implement. Alternative strategies that can produce quick results in reducing electricity costs are needed. One such alternative is a programme called Demand Market Participation (DMP). The DMP programme was implemented by Eskom, South Africa’s national electricity utility, to reduce electricity demand during supply shortages. This programme offers potential cost savings for clients with excess production capacity. Clients such as cement plants can switch off non-essential production equipment in Eskom’s peak demand periods for a financial incentive. To maximise the benefits for both the clients and Eskom, accurate electricity forecasting is needed, as are systems enabling a quick response to load reduction requests. In this study DMP opportunities on typical cement plants were identified. A DMP strategy to assist cement plants was developed to achieve maximum cost savings without influencing production, quality and safety. An existing energy management system (EnMS) was adapted to incorporate the new DMP participation strategy. The new EnMS and DMP strategy were implemented at a South African cement plant, resulting in savings of R220 000 per month. This translates into an annual cost-saving potential of R2-million for the plant, and an R13-million cost-saving potential for the total South African cement industry.