Flywheel units can provide instant, ride-through power of 190 kilowatts for 13 seconds--more than enough time to switch to generator--and are parallelable
for additional capacity.
Dayton, Ohio, has introduced their new parallelable
TreStar P line of online double-conversion three-phase Uninterruptible Power Supplies (UPS) for critical loads.
With a 38V to 55V input range, the PKM4402NG is also n+1 parallelable
without external circuitry.