Madhoo, HMdhluli, Sipho DMakopo, Raisibe SChapman, D2026-03-102026-03-102025-09http://hdl.handle.net/10204/14736South Africa's energy landscape is currently strained due to an aging power generation fleet and financial constraints, leading to frequent load shedding. This study explores how integrating Demand Response (DR) and Battery Energy Storage Systems (BESS) can enhance grid resilience and economic efficiency. Using the PLEXOS techno-economic tool, the research models South Africa's 2027 power system to determine the optimal use of BESS and assess the impact of varying levels of DR and BESS capacity. The findings reveal that BESS revenue is maximized when 50% of its capacity is allocated to ancillary services and 50% to energy arbitrage, indicating a need for a balanced operational strategy. A flexible revenue-generating range exists between 30% and 65% allocation to ancillary services. Three scenarios were modelled: Low, Moderate, and High penetration of DR and BESS. The results show that increasing DR and BESS integration significantly improves energy reliability. Specifically, it leads to an 80% reduction in unserved energy and its associated costs and a 42% decrease in the use of costly Open-Cycle Gas Turbines (OCGT). These findings underscore the tangible economic benefits and operational flexibility gained from strategic investments in DR and BESS, positioning them as key enablers for a resilient and cost-effective energy future for South Africa.FulltextenDemand responsePlexos modellingFlexibility servicesEnergy marketsOpen cycle gas turbineBattery energy storage systemsConference PresentationN/A