Loss Financial Evaluation and Total Ownership Cost of Transformers in Large-Scale Solar Plants

In the recent multifaceted transformation dawn of low-carbon power generation markets and escalated growth of the renewable energy technologies in South Africa, a comprehensive analysis of the technical and economic performance of transformers has been under-explored as a result of insufficient knowledge in this study area. The Transformer Total Ownership Cost (TTOC) is an economic evaluation pre-planned to give the transformer purchasers and owners the intended service-lifetime costs basis of their transformer's investment. The procedure for evaluating the transformer TTOC depend upon the concept of service-lifetime loss evaluation of transformers. Meticulously, this techno-economic concept considers the arithmetic sum of the presented discounted value (PDV) of a unit kilowatt loss of the transformer during its intended service-lifetime. In a competitive bidding process, the TTOC is employed as a criterion to select the most suitable option among competing offers by transformer manufactures and hence to substantiate the purchasing decision of the units capable of achieving maximum productivity at minimum expense. This work provides transformers' service-lifetime loss evaluation method which fulfills some of the operational requirements that have been introduced from the recent deployment of solar photovoltaic plants into the modern South African energy mixed electrical network. The proposed method herein takes into account the intermittent nature of the solar PV, annualized energy cost and services losses. The results yield a TTOC optimized for the operational requirements of modern solar PV plant in a South African context.