The 9 MWh and 6 MWh Kokam systems are designed to provide annual fuel savings of US$15 million to KEPCO. This figure is three times greater than the systems’ cost over their lifetime. Additional savings through a reduction in power plant "wear and tear" have also been targeted as has a reduction of KEPCO’s greenhouse emissions.
By supplying frequency regulation functionality, KEPCO can reduce the fossil fuel-fired "spinning reserves" required to support the grid, as variable grid demand and supply causes grid-frequency fluctuations.
"Frequency regulation…. needs systems that deliver high power, fast recharge rates and long cycle lives," said Ike Hong, VP of Kokam’s Power Solutions division. "Our energy storage systems provide KEPCO with the performance it needs to precisely and cost-effectively regulate frequency on the South Korean grid."
The new 15 MWh of battery capacity will be added to an existing 5 MWh lithium titanate oxide system deployed in August of last year. All three systems are a part of a larger on grid battery project; that targets 500 MW of battery capacity by 2017.
Kokam claims that the high energy density of its battery chemistry allows for 2.4 MWh of storage to be added in a single 40-foot container. The container employs a "direct cooling" design, and Kokam says its heat dissipation rate is 1.6 times better than standard NMC technology.
Kokam says its NMC batteries can last for up to 10,000 cycles and can charge and discharge at maximum power rates of 4C, 8C and 15C.
While deployed for frequency regulation in this instance, Kokam says its large scale storage units can also be used for solar and wind production smoothing, transmission and distribution investment deferral, demand response and peak load shaving.
IHS Technologies forecasts have Korea as set to be the third largest energy storage market globally in 2016, with 280 MW of storage capacity to be added in the country over 2015 and 2016.