The first fault occurred at about 9 o'clock this morning.
300 ESB customers are without power in Offaly today.
A fault in Clara, reported at 11.30, is affecting 171 homes and businesses.
Elsewhere, 128 properties are affected by two outages in the Edenderry area.
ESB Networks is apologising for the loss of supply and crews are currently working to repair the fault.
Power is expected to be restored to 89 customers in Edenderry by lunchtime and by about 3 o'clock elsewhere.