“From my college days I remember learning that DC was not good at long distance transmission. Yet, Britain and Ireland are transmitting DC across the Channel.”
a couple of things about that claim make zero sense:
1. DC power was a dead-end back in the first days of the fight between DC and AC power because DC power plants essentially had to be built on every block due to distance limitations of transmitting DC power ... the power that lit the Chicago World’s Fair was AC power delivered from Niagara Falls ...
2. AC-to-DC conversion and then DC-to-AC conversion would be necessary for DC power to be injected into and then extracted form said DC link ... that would require MASSIVE motor-generators on each end of said DC link to do this. why not just transmit AC to start with?
- a couple of things about that claim make zero sense:
1. DC power was a dead-end back in the first days of the fight between DC and AC power because DC power plants essentially had to be built on every block due to distance limitations of transmitting DC power ... the power that lit the Chicago World’s Fair was AC power delivered from Niagara Falls ...
2. AC-to-DC conversion and then DC-to-AC conversion would be necessary for DC power to be injected into and then extracted form said DC link ... that would require MASSIVE motor-generators on each end of said DC link to do this. why not just transmit AC to start with?-
Converting high power AC to DC and back from DC to AC is used with solid state Insular Gate Bipolar Transistors (IGBT) or Thyristor switching elements not motors and generators.
Also, the bulk, long-haul power transmission is cheaper by HVDC vs HVAC including the cost of converters. You will see more long-haul bulk power by HVDC in the future.
On the other side HVDC transmission will not provide rotating inertia to the grid.