There has to be certain basic minimum power available for vital installations and cities. This can be done by islanding that area, such as in Mumbai. We should also have small power plants; of 10, 20 or 50 MW combined heat and power units depending on the size of the city, which produce about 20 percent of its requirement. This should work as a peaking plant [which runs only when demand is high] every day and also double up as the emergency supplier.