As I pointed out this whole business of smart grid is no easy thing because of variability involved in practically every thing.I believe not more than 10-15% of enewable energy can be integrated peacefully and without much cries and this business of Time of the day demand tariff for domestics, at least has to be given good by.Otherwise we may land with some thing that becomes unmanageable.As I predicted and I feel those exponents of Renewables who some how want to go to 50% of total energy use, should also think of green fields and farmer community and independence that comes from not being dependent on Utility . Solar Energy is best for such exponents because it is totally independent and free except one needs the equipment. I believe this is what we plan for Delhi/ Bombay. Even in cities people can go for solar and relieve load on the Distribution network and then expand the load at ease. Sooner or later the technology will come for storage or they can remain connected to the grid as a standby. As it is, in the night there is less load except in Summer.So variability has to met by variable policies and not by engineering! I have already estimated that no more than 500 MW can be injected or used in Delhi city as solar power. To think for a. bigger figure - necessary to go to neighbouring villages etc and preferably build standalone systems . Of the 20,000 MW solar power that is projected to be build - I believe much of it could be stand alone systems in 20,000 Villages not yet electrified.