this is from someone elses post here:
AC advantages
� Is easy to transform
� Can be transmitted at high voltage, low current and transformed to low voltage, higher current
� Energy losses in transmission can be minimised by high voltage transmission
� Motors and generators have fewer moving parts so more reliable and easier to maintain
� Three phase motors (huh?) powerful for industry use
AC disadvantages
� Back emf due to eddy currents lowers power
� Emitted electromagnetic radiation interferes with other electronic equipment
� Requires thick insulation to minimise interference from other cables
DC advantages
� Does not need as much insulation as it has no electromagnetic radiation output
� No back emf
� No high frequency radiation to cause interference in other equipment or signals
� Transmission has no energy loss due to induction in adjacent lines and metal structures
DC disadvantages
� Can�t be transformed!
� More difficult to supply to houses by line distribution
� Equipment not as reliable due to sparking and wear across split ring commutator
� Sparking causes interference