Hi Ahmad,

quite an interesting and challenging question. We are dealing with microgrids at present and your question has actually many answers. My impression, based on some preliminary simplified simulation is that technologies with inverter interface may be controlled so fast that any unbalanced caused by wind/solar fluctuation can be compensated. This is for instance the case of Battery Storage, the wind itself to transfer part of blade inertia, and solar (in reduction mode only). However I can see constraints  since some aggressive operational mode can have an impact on lifetime, and economic impact since reducing RES production may require market compensation for balancing service.  

As already pointed out various possibilities are available depending on the situation. Major solution is through adoption storage device that can help you in storing exc3ss generation availability and supplying during shortage. Though nothing can be said about the economy feasibility of generation balance does exist.

Considering stochastic nature of wind and PV, their economy is stochastic as well....Hence to ensure the load and generation balance while dispatching it economically is a challenging task for ISO's.