A. Lifetime, Cycling and Degradation
The most critical factor for the lifetime of a FESS is the
chosen type of bearing. If contactless and wearless magnetic bearings are applied, the lifetime can reach 107 cycles and the life span is at least 20 years . Li-ion batteries in PV systems have an operating time of approx. 5 000 cycles (10 – 15 years), and LA batteries up to 3 000 cycles (7 – 10 years) at 50% depth of discharge (DOD). Furthermore batteries show a significant degradation over time whereas FESS does not.