Re:Power Prices Go Negative in Germany
by jacquesm on Tuesday December 26, 2017 @07:36PM
(#16011992)
Oversupply will only cause the grid frequency typically to go up fractions of a Hz and if the power variations are slow enough the grid can easily match the change. Real problems turn up when the system has to shed or absorb load very rapidly.
But usually that's not the case. The grid is first and foremost a power delivery mechanism, not a precision timebase and besides some efficiency issues (resonant cores tend to work best at the frequency they are designed for, such as all transformers in the grid) frequency variation is expected and can be dealt with within limit without further countermeasures.
Far worse than frequency variation would be phase errors leading to massive consumption of power within the grid and imbalance in voltage between phases because it will cause generators or industrial equipment to either break or go into fault states.
Think of the grid as a massive flywheel and frequency variations are slowing down or speeding up that flywheel.
So even if the grid can't store energy directly it can absorb pulses quite well and there are devices that grid operators use that use superconducting coils at very low temperature to stabilize the grid even further. Siemens and a number of US based companies have had these in production for quite a few years, typically you'll find them right next to large windfarms.
But usually that's not the case. The grid is first and foremost a power delivery mechanism, not a precision timebase and besides some efficiency issues (resonant cores tend to work best at the frequency they are designed for, such as all transformers in the grid) frequency variation is expected and can be dealt with within limit without further countermeasures.
Far worse than frequency variation would be phase errors leading to massive consumption of power within the grid and imbalance in voltage between phases because it will cause generators or industrial equipment to either break or go into fault states.
Think of the grid as a massive flywheel and frequency variations are slowing down or speeding up that flywheel.
So even if the grid can't store energy directly it can absorb pulses quite well and there are devices that grid operators use that use superconducting coils at very low temperature to stabilize the grid even further. Siemens and a number of US based companies have had these in production for quite a few years, typically you'll find them right next to large windfarms.