Water and energy Balancing the business of energy and water As an organisation that constantly strives to limit increases in water consumption and contribute to sustainable water use, Eskom has indicated its commitment to improving the way in which South Africa’s water resources are managed. Eskom’s Nandha Govender provides insight into how this is being achieved. Article by Debbie Besseling. ith a track record of have to go beyond our own interests. some 15 years at Eskom, The idea, which is part of our strat- Govender joined the egy, is that in the course of doing Worganisation’s Generation Divi- our business, we have to find ways sion’s Primary Energy, Water Supply and means of reducing our water ABOUT NANDHA Department in 1998 as a mechani- footprint, and managing our current GOVENDER cal engineer. Today, he is the Acting water resources so that others will General Manager: Operations, under have access to it as well.” • Professional registration: the group’s Commercial and Tech- Eskom Holdings SOC Limited Engineering Council of SA nology: Primary Energy Division, is a large consumer of fresh water, • Other memberships: Certified where he is responsible for integrated accounting for approximately 2-3% Director- Institute of Directors; planning and operations of primary of the country’s total water con- National Society of Black Engineers energy resources such as coal, water sumption annually. Eskom power • Academic qualification: and limestone. In this role he pro- stations run constantly, supplying Bachelor of Science (Mechanical vides general management of the in excess of 95% of South Africa’s Engineering), University of Durban coal supply, water supply, logistics electrical energy and more than half Westville, 1995 operations as well as environmental of the electricity used on the African • First job: Apprentice diesel and technical services; a position continent. mechanic that he enthusiastically describes as Govender adds: “It is expected • Own personal vision: I am the having a new challenge every day that Eskom’s water usage will light and from one light many can and an opportunity to learn some- increase over the next 10 years due be lit thing new. to the return to service of older • Likes: Education in human values According to Govender, one of wet-cooled power stations and the • Dislikes: Wastage of electricity the major challenges for the organi- introduction of new power stations. and water taps left running sation is the security of water sup- However, with the introduction of • Currently reading: Intuitive Lis- ply to its power stations in the long more dry-cooled stations, diversifi- tening: How Intuition Talks Through term. “This is a major area of focus cation of the energy mix and energy You by Christiane Northrup and for us. We have existing and new and water efficiency measures, Mona Lisa Schulz. power stations that last anywhere Eskom’s relative and absolute water between 50 and 60 years and it is consumption will improve consider- very important to ensure that water ably by 2030.” re-use of mine-water; and minimis- is available to sustain these power Eskom has several overarching ing the impact of its activities on stations. Secondly, to ensure proper environmental objectives relevant groundwater resources. planning, and that water resources to addressing the water challenges, and infrastructure planning is done namely avoiding harm to the natural ACHIEVING OBJECTIVES to make sure that we deliver water to environment; reducing freshwater THROUGH INNOVATION the power stations for the life of the usage; eliminating liquid effluent power stations. We are competing discharges through effective water skom has achieved significant for limited resources. We as Eskom management processes and the Ewater saving objectives through 36 The Water Wheel January/February 2014 Water and energy the implementation of various Figure 1 - Eskom’s projects over the past two decades. water use per unit of energy over the last One major innovation has been dry 40 years. cooling. To date, 17 of the newest Eskom coal-fired power generation units (at Grootvlei, Matimba, Kendal and Majuba) have been installed with dry-cooling systems. Water consumption from these units is 15 times lower when compared to conventional wet-cooled units. In addition, a policy decision has been made to implement dry- cooling technology at all new coal- Eskom Courtesy fired power plants. Thus Medupi and Kusile will be equipped with dry- treat and use mine-water at Kriel and use at the organisation’s power sta- cooling technology. Figure 1 illus- Matla power stations from the tied tions. Stations have identified major trates the positive impact of water coal collieries. The project is cur- streams, and plans are underway to usage following the introduction rently in the feasibility phase. The install flow meters at strategic points of dry-cooled large six pack power estimated time for the operation of as part of the technical plans to be stations during the period of 1983 to the plant will be in the next three implemented over a period of three 1993. It is anticipated that this will to four years. There is a temporary years to ensure full compliance to further improve with the commis- desalination plant in place, with the directive. sioning of the world’s largest dry- plans to build a permanent plant at Eskom also sets water-use tar- cooled power stations, Medupi and Lethabo Power Station for the use gets in terms of litres of water used Kusile, which are currently under of mine-water from its tied coal per unit of electricity produced for construction. colliery. each power station every year. The The second water-saving project Sewage is also treated and re- water targets are linked to the Eskom relates to diversification of Eskom’s used. Most of Eskom’s coal-fired Sustainability Index. The targets are water mix. Through the reuse of power stations (10 of the 13 stations) benchmarked against historical as treated mine-water from its coal treat and recover sewage water for well as designed water consumption suppliers and treated sewage recov- use in their operations. The total for each type of plant. ery the power company has man- amount of sewage water reuse is All power stations have water aged to reduce its freshwater usage. approximately 5 million m3/a. use performance targets that are To reduce the intake of freshwater A further innovation is Eskom’s set and monitored on a monthly at Tutuka and Lethabo power sta- implementation of a Water Account- basis and reviewed each year. The tions, mine-water is being sourced ing Framework (WAF) directive. The target setting is based on the station from nearby tied collieries, desali- objective of the WAF is to facilitate design and technology, water use nated and used to augment the sound water and effluent manage- performance, water quality and sta- Eskom accounts for freshwater supply. The total volume ment by prescribing minimum tistical/regression analysis of each up to 3% of South of mine-water recovered to Tutuka requirements for the monitoring, power station. Eskom achieved its Africa’s total water and Lethabo is approximately accounting and reporting of water best overall water use performance consumption. 8 million m3/a. Eskom has also increased its use of desalination plants. A desalina- tion plant is already in place at Tutuka Power Station to utilise excess mine-water from its tied coal colliery. An additional project, to be completed at the end of the finan- cial year, aims to manage the result- ant brine with the construction of a brine pond. Furthermore, there is a project underway for the development of a large-scale desalinisation plant to Eskom Courtesy The Water Wheel January/February 2014 37 Water and energy whose overall objective is to reduce the 17% water resources demand gap by 2030, as well as in severely stressed catchments whose water balance is in deficit. The SWPN-SA has formed three working groups which focus on the following: • Working group on Water Effi- ciency and Leakage Reduction: Focus on water use efficiency, reducing water losses and water wastage in the Municipal Sector. Group led by Nestle (South Africa) and Sasol; • Working group on Agriculture and Supply Chain water: Focus on Agricultural Supply Chain and irrigated agriculture, led by Coca Cola (South Africa); • Working group on Effluent and Courtesy Eskom Courtesy Waste Water Management: Huge potential for increasing reuse An aerial view of of 1.34 ℓ/kWh in the 2012 financial of waste water at the coast as Matimba Power Station, WHERE DOES ESKOM year against a target of 1.35 ℓ/kWh. well as in inland systems. Focus one of Eskom’s dry- USE ITS WATER? As a strategic water user Eskom on mine-water and municipal cooling stations. is committed to being proactive in effluent treatment, led by Eskom • At the coal-fired stations, water establishing water management and Johannesburg Water. is used to generate the steam procedures and initiatives to that drives the turbines to gener- protect water resources and pro- The SWPN-SA is a water manage- ate electricity, and for cooling mote conservation and judicious ment partnership between govern- purposes use of water in support of the ment, the private sector and civil • Water is used to drive the turbines national policy. A Memorandum society. to generate electricity at its hydro of Understanding (MoU) has been power and pumped storage signed between Eskom and the schemes GREATEST MILESTONE OF Department of Water Affairs to • Most power stations treat raw CAREER promote, encourage and support water to produce potable water good water management practices for certain processes and to supply ovender relates the greatest in areas of Water Conservation the nearby communities and coal milestone of his career: “I was and Water Demand Management G collieries for domestic purposes appointed to the Governing Board (WCWDM) within the power • Sea water is used for cooling of the first catchment management generation sector.