Reactive power is energy using for nothing. When have parallel works two generators with different voltage but working together. This means have already current between them. If both generator working with same parameters there will be no difference and no or very small reactive power. Reactive power is capacitive or inductive, dependence from load. Normal el. motors make inductive power. With capacitor in line is possible to reduce inductive power. Power factor when is 1 is means no reactive power on line. When is smaller is means need to improve line normally to about 0,8. For fluorescent light inside have condenser because is again inductive power.