You would need to convert the electricity to a http://en.wikipedia.org/wiki/Grid_energy_storage" and then convert it back when you needed it.
For short intervals (say, giant battery arrays for windfarms for days when there is less / no wind), and on small scales (say, a home http://www.beaconpower.com/index.htm" to allow for off-peak electricity buying, or in event of a prolonged power outage, or an Uninterruptible Power Supply for your computer) this has been done.
What has not been done is to do this "buffering" on a massive scale for a long duration (say, all of India, during the four months of summer). Something of this magnitude would need to be massive, or in every home, or both. It all comes down to economics: how expensive is it to store this energy (including conversion and storage efficiencies), as opposed to building more capacity, and is there enough money to do either?