Negative electricity prices in electricity markets: causes, impacts, and response strategies

• Identify and analyze the key driving factors behind negative price occurrences and their interrelationships within different national market contexts; • Evaluate the specific impacts of negative electricity prices on the behavior of market participants, system operating costs, and overall power system reliability; • Systematically review, compare, and evaluate the mitigation strategies implemented in the studied markets, encompassing adjustments to market mechanisms, deployment of relevant technologies, and modifications to policy frameworks; • Offer targeted and actionable policy recommendations and decision support for electricity market designers and policymakers. Against the backdrop of the accelerating global clean energy transition and the rapid increase in renewable energy source (RES) penetration, temporal imbalances between supply and demand in power systems are becoming increasingly prominent. Consequently, the phenomenon of negative electricity prices has evolved from sporadic occurrences into an increasingly prevalent market signal. This paper focuses on case studies of negative electricity prices in major international electricity markets (the Netherlands, Germany, Australia) and selected provincial markets in China (Shandong, Zhejiang). It systematically analyzes their underlying causal mechanisms, assesses their multidimensional impacts, and comparatively examines the mitigation strategies adopted across these diverse markets. The study reveals that the core driver of negative prices is the concentrated high generation feed-in from RES during low-load periods. This is concurrently influenced by multiple factors, including insufficient system flexibility, inter-zonal transmission congestion, and constraints imposed by specific market rules such as subsidies and bidding strategies. Major international electricity markets are widely exploring mitigation measures such as optimizing market clearing mechanisms, incentivizing energy storage and demand-side response, and adjusting subsidy policies. In contrast, the occurrence of negative prices in China’s electricity markets, while sharing common drivers, also exhibits complex correlations with domestic factors, notably medium- and long-term contracts and market power dynamics. Consequently, formulating and implementing differentiated and systematic mitigation strategies, drawing upon international experience while being tailored to China’s specific national context, is crucial for the long-term sustainable development of its electricity markets.