Complex sentence: Since January 2016 in South Korea three battery storage power plants in operation: a 24 MW system with 9 MWh and a system 16 MW with 6 MWh.
Split into simpler sentences: Since January 2016 in South Korea three battery storage power plants are in operation. There are two new systems, a 24 MW system with 9 MWh and a 16 MW system with 6 MWh.