Aquifer thermal energy storage (ATES) for district heating and cooling systems: A review

• ATES’ role as seasonal thermal energy storage for district energy networks are limited. • Modeling of ATES can be categorized into three approaches – Detailed modeling with building input data, co-simulation and modeling with reduced order models. • Real world implementation of ATES is predominantly in Northwestern Europe. • Review showcases ATES technology has potential for decarbonisation of district energy sector. Seasonal thermal energy storage plays a pivotal role in transitioning district heating and cooling (DHC) systems toward the use of renewable energy. Among the available technologies, aquifer thermal energy storage (ATES) emerges as a promising form of sensible heat storage, utilizing the subsurface as the storage medium. This study reviews the integration of ATES systems with DHC networks, drawing insights from various case studies in the literature. It identifies and summarizes real-world ATES implementations at district scale and explores different modeling approaches for coupling ATES with DHC systems. Furthermore, we identify technological, policy, and deployment challenges that hinder the current widespread adoption of ATES with district energy networks such as ATES oversizing during design phase, market uptake during implementation and thermal imbalances during operational phase. By synthesizing findings from multiple case studies, this review highlights the current state of ATES technology and its significant potential to enhance the flexibility, efficiency, and sustainability of modern low-carbon DHC systems. Furthermore, we also identify that using a holistic system approach in analysis can support decision makers in implementing ATES at a district scale.