Kokam has successfully deployed two Lithium Nickel Manganese Cobalt (NMC) Oxide Energy Storage Systems (ESSs)—a 24-megawatt (MW) system / 9-megawatt hour (MWh) and a 16 MW / 6 MWh system—for frequency regulation on the South Korean electricity grid. The 24 MW system is the largest capacity Lithium NMC ESS used for frequency regulation in the world.
Operational since January 2016, the two new systems, along with a Kokam 16MW / 5MWh Lithium Titanate Oxide (LTO) ESS system deployed in August 2015, provide South Korea’s largest utility, Korea Electric Power Corporation, with 56 MW of energy storage capacity for frequency regulation. These three systems are part of the world’s largest ESS frequency regulation project, which is scheduled to have deployed 500 MW of battery-based energy storage when it is completed in 2017.
In addition to improving grid reliability, the Kokam ESSs will enable KEPCO to improve its operation efficiency by reducing its need for spinning power generation reserves. This will allow KEPCO to shift energy generation to lower cost, more efficient power plants and decrease wear and tear on all its power plants.
For example, the three Kokam ESSs will deliver an estimated annual savings of US$13 million in fuel costs, providing fuel cost savings three times larger than the ESSs’ purchase price over the systems’ lifetimes. In addition, by reducing the amount of fossil fuels burnt for frequency regulation, the Kokam ESSs will help reduce KEPCO’s greenhouse gas emissions.
The new 24 MW and 16 MW Lithium NMC ESSs utilize Kokam’s innovative Ultra High Power NMC battery technology. Designed for high-power energy storage applications, such as frequency regulation, wind or large solar power system ramp rate control, Uninterrupted Power Supply (UPS) and voltage support, Kokam’s Ultra High Power NMC battery technology delivers:
Higher energy density: This higher density enables 2.4 MWh of energy storage to be installed in a 40-foot container, compared to 1~1.5MWh of energy storage for standard NMC batteries.
High power cycle life: Ultra High Power NMC batteries can last up to 10,000 cycles, compared to 3,000 - 5,000 cycles for standard NMC technologies, increasing an energy storage system's expected life.
Better charge, discharge and max power rates: Ultra High Power NMC battery technology has charge, discharge and max power rates of 4C, 8C and 15C, compared to 2C, 3C and 4C for competitors. This enables Ultra High Power NMC systems to receive and dispatch more power when needed.
Improved heat dissipation: With a heat dissipation rate that is 1.6 times better than standard NMC technologies, Ultra High Power NMC batteries can be used at a higher rate for longer periods of time with no degradation in battery life or performance.
The systems also use Kokam’s KCE 40-foot container, which features a direct cooling design, in which the container’s Heating Ventilation and Air Conditioning (HVAC) system only regulates temperatures inside the system’s racks rather than the entire container. This results in 70% less air conditioning auxiliary load than standard containers.