Yes, all solar installations are not cheaper than all coal installations.

But conversely, all coal is not cheaper than all solar!

That applies globally and in India.

The point is that solar costs are declining every year, by 10% p.a. In many sunny places it is already at parity or below (eg Arizona, Mexico, Rajasthan and Gujarat in India, Mexico). We have already seen several bids this year at US¢ 3/Kwh ($30/MWh). $20/MWh is in sight - that would be well under the cheapest coal.

This link is useful summary http://cleantechnica.com/2016/04/15/why-energy-experts-are-s...

(And none of this accounts for the massive unpriced carbon + health externality of coal plants).

Coal is staying at best flat + whatever the fuel cost.