Two types of current -
Direct current flows only in one direction.
DC electricity can be produced by a number of devices.
Solar photo voltaic cells
For gird DC must be converted to AC by inverter
DC electricity has following disadvantages
Higher line loss
Higher capital cost
Alternating current -AC
In an alternating current the electrons periodically reverse direction of flow through the material in one direction and then reverse their path and flowback in the other direction.This happens over and over again at a rapid rate.
Current changes direction 120 times per second.
AC produced by generators.
Inverter can convert AC to DC
Grid generally use AC power
AC is easily converted from high to low voltage
High voltage used for long distance transport
Power reduced to lower voltage for customer equipment