The stationary energy storage industry has begun to explore grid-scale hybrid solutions known as hybrid energy storage systems (HESSs). Navigant Research defines a HESS as a stationary ESS that integrates two or more energy storage technologies with complementary operating characteristics. The aim is to deliver power capacity, energy duration, and cycle life in a single system that is not achievable by any one energy storage technology. The advantages to deploying HESSs over typical stationary ESSs include lower cost, increased system efficiency, increased system lifetime due to optimized operation, and the ability to do more and last longer with less overall storage capacity. HESSs have the potential to change the energy storage landscape and give customers better options to service their needs. Much of the continued growth of the industry will occur alongside the maturation of pure-play battery energy storage technology. The future of the HESS industry in any market will be largely decided by customer and grid operator needs, evolving market structures that value flexible resources favorably, and the local utilities’ views on new technology. According to Navigant Research, global installed HESS power capacity is expected to grow from 78.6 MW in 2017 to 2.1 GW in 2026. This Navigant Research report analyzes the global market for utility-scale and customer-sited HESSs. The study examines the market drivers and barriers and technological trends affecting the deployment of HESSs around the world. Global forecasts for power capacity, energy capacity, and revenue, segmented by region, technology, and market segment, extend through 2026. The report focuses on current and future technologies in the HESS market, including battery-battery, battery-capacitor, and other hybrid systems.