I got this table from http://www.aweablog.org/output-records-and-nerc-report-show-increasing-r....
It summarizes on one table all the grid reliability services provided by a wind power plant and compare it to conventional power plants. It covers LVRT, frequency support, reactive power and voltage control, active power control, frequency response and others. The technology exists, what is lacking are policies and compensation mechanisms for wind plants to provide these valuable grid reliability services.
| Reliability service | Wind | Conventional generation |
| Ride-through | – Excellent voltage and frequency ride-through, meeting FERC Order 661A requirements– Power electronics electrically separate wind turbine generators from grid disturbances, providing them with much greater ability to remain online through disturbances | – Many cannot match wind’s capabilities or meet Order 661A ride-through requirements |
| Reactive and voltage control | – Wind turbine power electronics provide reactive and voltage controlequivalent to that of conventional generators– Power electronics can provide reactive power and voltage control even when the wind plant is not producing power | -Conventional generation provides this service. |
| Active power control | – Can provide extremely fast response in seconds, far faster than conventional generation– Like other generators, wind will provide this response when it is economic to do so- Xcel Energy sometimes uses its wind plants to provide some or all of its frequency-responsive automatic generation control
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– Like wind, many baseload generators do not provide active power control for economic reasons, though they technically can |
| Frequency response | –Adding wind can help system frequency response by causing conventional generation to be dispatched down-Wind can provide frequency response, but it is typically more costly for it to do so than for other resources as it requires curtailing wind generation in advance | – Changes in conventional generator operating procedures have greatly reduced frequency response– Only 70-75 percent of generators have governors that are capable of sustaining frequency response for more than one minute, and about half of conventional generators have controls that may withdraw sustained frequency response for economic reasons– “Only 30 percent of the units on-line provide primary frequency response. Two-thirds of the units that did respond exhibit withdrawal of primary frequency response.” So, “Only 10 percent of units on-line sustain primary frequency response.” |
| Inertial response | –Can provide with no lost production by using power electronics and the inertia of the wind turbine rotor; this capability is commercially available but not widely deployed because there is no payment for any resource to provide this service | -Conventional generation provides this service. |
| Increases need for operating reserves, integration cost | – Very small impact on total reserve need and integration cost | -Contingency reserve needs and costs are quite large |