Grid imbalance between generation and load is monitored and balanced by tracking changes in AC line frequency, commonly referred to as ‘frequency response’. The rotating mass of generators (spinning wire coil within a magnetic field) provide a flywheel inertia buffer to sudden changes in load demand. As load demand suddenly increases beyond this buffer capacity and the flywheel starts to slow, line frequency decreases. If load demand suddenly decreases, frequency will increase but is typically dealt with by reducing generator output. Rapid response to a decreasing frequency event is critical in preven0ng a cascading loss of service.
Dedicated peaker generators and renewable generation resources such as wind, wave, and solar are not dependable sources to mitigate sudden peak load demand. Peakers take time to come online and renewables can exacerbate the overload condi0on by going off-line at an inopportune point in time.
LICAP ultracapacitor systems provide additional inertia buffering against sudden load changes within milliseconds. This fast response stabilizes the deviant change in frequency and bridges the time gap in bringing additional generator capacity on-line.