29 August 2013 – Pragma, supported by Aurecon Energy Services, conducted a technical review of four key transmission substations for NamPower in May and June 2013. Project manager and partner consultant at Pragma, Karl Nepgen, says, "The intervention was to assess the condition of various operational and asset management areas, by evaluating the quality and effectiveness of the current maintenance and operating practices."
The four transmission substations reviewed included Auas (outside Windhoek), Kokerboom (vicinity of Keetmanshoop), Omburu (near Omaruru), and Kuiseb (on the edge of the Namib, inland from Walvis Bay). According to Nepgen, "The review findings were based on the consideration of a combination of aspects, including the risk of complete equipment failure or network outage, the risk to quality of supply (e.g. failure of a power transformer causes power interruptions for a long period), the risk to personnel and environment, urgent maintenance required to reduce risk and to ensure extended life of the equipment, and lastly, the expected remaining life of the equipment."
The review was performed by a combination of information scrutiny (off-site) and physical (on-site) assessments. Says Nepgen, "At each site, the physical walk-through and inspections were done under the accompaniment of the local network operations district staff member, who related his day-to-day operations experiences and answered questions from the consultants."
The consultants then viewed all major equipment areas, and recorded observations on structured score sheets, for subsequent capturing in electronic format. "In addition, high-resolution digital photographs were taken from ground level only, to both record evidence of observations and to reveal detailed information not visible at eye level, e.g. nameplates and sight glass condition."
Each site visit was concluded by feedback high-level summary of findings to the network operations staff, and highlighting of specific issues (if any) for short-term action. "In general, the substations reviewed were found to be in very good condition and well maintained. Achieving such a positive outcome is partly due to very beneficial climatic conditions at the inland sites, but also largely due to a highly experienced, very hands-on technical workforce in the transmission business unit."
As a benchmarking measure, Dio du Toit, technical director, Aurecon Energy Services, recounts that he has been involved in audits, which included the condition assessment audits of 20 municipalities in South Africa, as well as some major transmission substations of Eskom like Sol, Beta, Hydra and Koeberg. Says Du Toit: "If a comparison could be made between the South African situation on the one hand, with the condition of NamPower network on the other hand, NamPower compares very favourably."
The technical review was preceded by an asset management maturity assessment of the transmission asset maintenance division, performed by Pragma towards the end of 2012. The technical review project complemented the first project, and the findings correlated well.