Efficiency improvements to the hydro power plants in the Laxapana complex

Abstract

The main objective of this research is to present effective efficiency improvements to the hydropower plants in the Laxapana Complex. At present, electricity consumption in Sri Lanka is being increased at a rate of about seven present. Hence, improving the efficiency in an existing hydropower complex will lead to an increase in the electricity generation capacity of the National Grid using the same waters of the existing schemes. In this research, observed key areas are techno-economically analyzed with the view of efficiency improvement. All the areas introduced are important when they are viewed as total energy improvement projects. However, In order to implement a project, it should be viable. Hence, in this report, certain areas are discussed, and only viable modifications are presented as efficiency improvement projects. In this study, efficiency improvement to the Old Laxapana power station through a new generator design, capacity improvement to the Laxapana pond in order to minimize annual water spilling, new generator installation to the Samanala Power Station and leakage analysis of the New Laxapana tunnel have been proposed. For the analysis, past data and the findings of certain researches have been used. The study of the Old Laxapana Power Station was carried out focusing on the Old Laxapana Stage-II generators. From the cost-benefit analysis, a simple payback period of four years was observed. Next, from the cost-benefit analysis of the capacity improvement of the Laxapana pond, a payback period of 14.3 years found, and it was accepted considering the lifetime of the dam proposed. After that, a seven-year simple payback period was observed by proposing a 13.6 MW-generator for the Samanala Power Station as capacity improvement. Finally, the tunnel leakage analysis for the New Laxapana power station was carried out, obtaining 6.5-year simple payback period, and, hence, it was recommended to implement the repair during the rehabilitation.