Since smoothing intermittent wind and solar power fed into the grid is an area of interest and innovation, here’s some news.  The first link is a press release about this new product.  The second provides more detail about the Solar Tie inverter system (and contains a link to a brochure).

Similar to wind farms, solar power plants must meet requirements for reactive compensation in a growing number of countries. Employing the same technology as AMSC’s proven D-VAR system, which is connecting more than 70 wind farms worldwide to the grid, the SolarTie system provides instantaneous detection, accurate response and immediate results, ensuring efficient energy production and precise grid management. For example, if a disturbance occurs (voltage sag or swell, passing clouds or other event) the SGI will command the PV plant’s SolarTie inverters to provide the needed reactive support to control the voltage at the POI. AMSC’s SolarTie system provides sub-cycle (less than 16 milliseconds) detection and response to grid disturbances. 

http://phx.corporate-ir.net/phoenix.zhtml?c=86422&p=irol-newsArticle_Print&ID=1481362&highlight=

http://www.amsc.com/products/solartie/index.html

-Steve

Dr. Stephen R. Humphrey, Director,
School of Natural Resources and Environment,
Box 116455, 103 Black Hall, University of Florida
Gainesville, FL  32611-6455  USA
Tel. 352-392-9230, Fax 352-392-9748
http://snre.ufl.edu