From: A critical review of the integration of renewable energy sources with various technologies
 | Technologies of Flexibility | Technologies of Grid |  |  | ||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Changes to large VRE-generators | New or modified conventional, large generators | Centralised stocking | Centralised response to demand | VRE predictive technology | Strengthening/expansion of the transmission grid | Systems transmission of HVDC | Power flow controller | Power reaction controller | Power providers inertia or short-circuit | Central monitoring & control of the feed-in | ||
Limited VRE generator dispatch-ability | √ | √ | √ | √ | √ | X | X | X | X | X | X | Balance |
Insufficient appropriateness of short-term generation | X | √ | √ | X | X | X | X | X | X | X | X | |
Inadequate firmness of VRE engines | √ | √ | √ | √ | √ | X | X | X | X | X | X | |
Insufficient VRE generator forecast | √ | √ | √ | √ | √ | X | X | X | X | X | X | |
Insufficient adequacy for long term generation | √ | √ | √ | √ | √ | X | X | X | X | X | X | |
Rising excursions at local voltage | X | X | X | X | X | X | X | X | X | X | X | Quality |
Unreliable shutdown at blackout | X | X | X | X | X | X | X | X | X | X | X | |
Stepping up harmonic distortions | X | X | X | X | X | X | X | X | X | X | X | |
Increasing flicker | X | X | X | X | X | X | X | X | X | X | X | |
Increasing interactions between controls | √ | X | √ | X | X | X | √ | X | √ | √ | X | Stability |
Diminishing reserves of frequency control | √ | √ | √ | X | X | X | X | X | X | √ | X | |
Insufficient synchronization of the voltage trip limits | √ | X | √ | X | X | √ | X | X | X | √ | X | |
Insufficient coordination of frequency travel limits | √ | √ | √ | √ | X | X | X | X | X | √ | √ | |
Decreasing the level of inertia | √ | X | √ | X | X | X | X | X | √ | √ | X | |
Diminishing short-circuit power | √ | √ | √ | √ | X | X | X | X | X | X | X | |
Insufficient supply of reactive capacity | √ | X | X | X | X | X | X | √ | X | X | X | |
Greater transmission distances | X | X | X | X | X | X | X | X | √ | X | √ | Flow |
Missing capacity on the transmission grid | X | X | X | X | X | X | X | X | X | X | √ | |
Narrow limits of the trip voltage | X | X | X | X | √ | √ | X | X | X | X | √ | |
VRE generation lacking visibility | X | X | X | X | X | X | X | X | X | X | X | |
VRE generation lacks controllability | X | X | X | X | X | X | X | X | X | X | X | |
Increasing currents on short-circuits | X | X | X | X | X | X | X | X | X | X | √ | |
Insufficient nature of the defines | X | X | X | X | √ | √ | X | X | X | X | X | |
Flow patterns from lower grid rates are highly erratic | √ | X | X | X | X |  | X | X | X | X | X | |
Missing room on the distribution grid | X | X | √ | √ |  | √ | √ | √ | X | X | X | |
Increasing excursions to the regional voltage | X | X | X | X | X | √ | √ | X | X | X | X |