4 Comparison between wind and solar intermittency

Some general statements regarding the difference between wind and solar [13] that are of relevance to the intermittency issue:

  • PV has no apparent inherent inertia. Wind delivers power through fixed-speed induction or synchronous generators which have an inherent inertia, reducing the rate of change of frequency (ROCOF) after a disturbance.
  • Solar generation is thought to be easier to integrate into the system than wind generation because of its lesser impact on increased net load variability, compared to variability of load alone. This is due to the stronger correlation of solar generation output with load demand compared to wind generation.
  • Solar generation often has higher value to the system than wind, because of its availability during higher load demand-compared with wind, solar PV often tends to displace more expensive generation.

These points are further explored below.