Proving the Business Case for the Internet of Things

Kokam energy storage brings stability to South Korean grid

Steve Rogerson
March 15, 2016


What is claimed to be the world’s largest lithium nickel manganese cobalt (NMC) energy storage system is regulating frequency and improving grid reliability for Korea Electric Power.
Installed this year, the 24 and 16MW energy storage systems use South Korea based Kokam's ultra high power lithium-ion NMC technology to deliver high-power output, fast recharging and long-cycle life.
The two lithium NMC oxide energy storage systems (ESSs) are 24MW, 9MWh and a 16MW, 6MWh units for frequency regulation on the South Korean electricity grid. The 24MW system is claimed to be the largest capacity lithium NMC ESS used for frequency regulation in the world.
Operational since January 2016, the two systems, along with a Kokam 16MW, 5MWh lithium titanate oxide (LTO) ESS deployed in August 2015, provide South Korea's largest utility, Korea Electric Power (Kepco), with 56MW 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 500MW of battery-based energy storage when it is completed in 2017.
In addition to improving grid reliability, the ESSs will let Kepco 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$13m 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 ESSs will help reduce greenhouse gas emissions.
"Kokam specialises in the development of advanced battery technologies for the world's most demanding energy storage system applications, including frequency regulation, which needs systems that deliver high power, fast recharge rates and long cycle lives," said Ike Hong, vice president of Kokam's power division. "Our energy storage systems provide Kepco with the performance it needs to precisely and cost-effectively regulate frequency on the South Korean grid, helping it ensure the stability of this grid, improve its operational efficiency and lower its greenhouse gas emissions."
Hwang Woohyun, Kepco's senior vice president, added: "In the USA and Europe, Kokam has already garnered recognition for its exceptional lithium ion battery technology. Against stiff competition during the Kepco frequency regulation project procurement process, Kokam proved its competitiveness after a comprehensive economical and technical analysis. Kokam's 56MW of energy storage systems are making a major contribution to the stabilisation of our grid, and we hope to continue to cooperate with Kokam to develop energy storage projects that improve grid reliability, lower our operational costs and reduce our environmental impact."
The ESSs use Kokam's 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 and voltage support. The technology is said to deliver:

  • Higher energy density: This higher density enables 2.4MWh of energy storage to be installed in a 12m container, compared with 1 to 1.5MWh of energy storage for standard NMC batteries.
  • High power cycle life: The NMC batteries can last up to 10,000 cycles, compared with 3000 to 5000 cycles for standard NMC technologies, increasing an energy storage system's expected life.
  • Better charge, discharge and maximum power rates: The technology has charge, discharge and maximum power rates of 4, 8 and 15C, compared with 2, 3 and 4C for competitors. This enables 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, the 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 12m container, which has a direct cooling design, in which the container's HVAC system only regulates temperatures inside the system's racks rather than the entire container. This results in 70 per cent less air conditioning auxiliary load than standard containers.
"With some of the most innovative battery and other energy storage technologies on the market, 26 years of lithium-ion battery system manufacturing experience and 95MW of energy storage system capacity in operation around the world, Kokam has positioned itself as a leader in the rapidly growing energy storage system market," said Hong. "For applications such as frequency regulation, renewable energy smoothing, transmission and distribution investment deferral, demand response and peak load shaving, Kokam provides customers with advanced battery and other energy storage systems technologies that deliver superior performance at a competitive price."