Renewable generation is growing rapidly in South Australia. Renewable power to date has been uneconomic without subsidies. By 2025, wind, solar and battery costs will fall by 15%, 25% and 50% respectively. Consequently, if current cost trends continue, 2025 could very well see renewable energy and batteries overtake rival generating alternatives in dominating South Australia's power system with implications for gas demand. The region could become a leading case study on managing a power system in transition for other mature markets to follow.