Hybrid Energy Storage Systems (HESSs), combining multiple storage technologies such as lithium-ion batteries (LIB) with supercapacitors, hydrogen, flywheels, thermal energy, pumped hydro, and vanadium redox flow batteries, offer comprehensive solutions that enhance grid stability, reliability, and efficiency. 

Addressing Renewable Energy Challenges with HESS

Renewable energy variability creates timing mismatches between electricity generation and consumption, placing significant stress on conventional power grids. Energy storage systems play a vital role in addressing these challenges by providing crucial grid services. They support frequency regulation through rapid response capabilities of inverter-based systems, which balance supply and demand effectively.  

For voltage stability, storage inverters inject or absorb reactive power to maintain consistent voltage levels. Additionally, energy storage facilitates system restoration by delivering initial power quickly after outages and supports spinning reserve functions to enhance generator efficiency during standby periods.  

Beyond these, storage systems also contribute to energy management by enabling peak shaving to reduce demand spikes, energy arbitrage to capitalise on price fluctuations, and transmission deferral to postpone costly grid infrastructure upgrades. 

Why Hybrid Storage?

Large scale energy storage can be cost effective based on the geography or resources available, but may lack key characteristics such as response time or ramp up. A hybrid energy system can optimise performance by pooling complementary technologies :

• LIB-Supercapacitor:  Supercapacitors buffer quick, high-power transients, preserving battery life and improving system responsiveness. 

• LIB-Hydrogen Storage: Combines batteries’ fast response with hydrogen’s long-duration energy capacity, suitable for microgrids and grid-scale applications. 

• LIB-Flywheel: Flywheels handle high-cycle, short-duration power spikes, reducing battery degradation and system costs. 

• LIB-Thermal Energy Storage: Merges fast lithium-ion response with long-duration, scalable thermal storage for industrial uses. 

• LIB-Pumped Hydro:  Integrates pumped hydro’s long lifespan and bulk energy storage with LIB’s rapid response and operational flexibility. 

• Compressed Air-Thermal Storage: Enhances CAES efficiency using thermal storage to recover compression heat. 

• LIB-Vanadium Redox Flow Batteries: Combines lithium-ion’s power density with VRFB’s long cycle life and intrinsic safety in flow battery designs. 

Practical Applications and Case Studies 

In Indonesia, Surbana Jurong (SJ) and SMEC are collaborating on a project that integrates LIB with flywheel energy storage to address the high-power demands of industrial operations while optimising overall costs. SJ has also partnered with Higher Dimension Materials to develop a long-duration thermal energy storage (TES) and LIB hybrid system designed specifically for industrial parks.  

At the Balambano hydroelectric project, lithium-ion batteries are replacing diesel generators to enable faster black-start capabilities along with a significant reduction in emissions. Additionally, SJ and VFlowTech are working together to advance underground hybrid systems that combine LIB and vanadium redox flow batteries (VRFB), maximising land use efficiency and enhancing energy storage capacity for urban environments. 

By integrating hybrid energy storage technologies, we can overcome renewable energy intermittency challenges, enhance grid stability, and achieve ambitious decarbonisation goals while optimising lifecycle costs and system performance. To read more on this topic download our pdf now.