Browsing by Author "Van Dongen, Caroline"
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- ItemValuation of pumped storage in capacity expansion planning – a South African case study(Stellenbosch : Stellenbosch University, 2022-04) Van Dongen, Caroline; Bekker, Bernard; Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering.ENGLISH ABSTRACT: On the South African grid, pump storage schemes offer a range of benefits which can assist in the integration of increased variable renewable energy generation. The Integrated Resource Plan for South Africa currently proposes adding gas turbines and batteries to the future grid for peaking capacity and increased flexibility, with no added pump storage schemes. This thesis investigates the value of the services and contributions pumped storage provides the grid, the capital costs and history of this technology in order to determine its potential future role. The research aims to address the possible misconception of limited pump storage scheme site availability by providing an overview of site feasibility studies, including estimated cost projections and utilises these values in an energy optimisation model to investigate the economic case for pump storage.
- ItemValuation of pumped storage in capacity expansion planning: a South African case study(MDPI, 2021) Van Dongen, Caroline; Bekker, Bernard; Dalton, AmarisENGLISH ABSTRACT: According to South Africa’s national energy policy, network penetration of variable renewable energy (VRE) generation will significantly increase by 2030. Increased associated network uncertainty creates the need for an additional flexible generation. As the planned VRE is mostly nonsynchronous PV and wind generators, additional ancillary services will also be required. Pumped Storage (PS), which is a well-established flexible generation technology with fast ramping capability and the ability to contribute various ancillary services, could help integrate increased VRE penetration on the South African network. However, in the latest revision of South Africa’s energy policy, PS was left out in favor of gas turbines and batteries as favored flexible generation options. This paper explores the two-part hypothesis that PS was disadvantaged in the formulation of a national energy mix due to: (a) ancillary services provided by PS not being explicitly monetized in energy modeling software; (b) the uncertainties associated with project costing assumptions. The value of PS in terms of providing ancillary services is firstly explored using the international literature. Secondly, the impact of input-cost uncertainties is demonstrated by comparing pumped storage, gas turbines, and batteries using levelized cost of energy (LCOE) curves and the Tools for Energy Model Optimization and Analysis (Temoa), North Carolina State University, USA, optimization software. Based on LCOE calculations using revised cost assumptions, it is found that PS may indeed be preferential to gas turbines or batteries, particularly at large load factors. The authors hope that this research contributes to the scientific understanding of the role that PS can play in supporting the integration of generation from renewable sources for effective grid operations.