Citation please.
“Fossil fuel subsidies reached $90 billion in the OECD and over $500 billion globally in 2011.[1] Renewable energy subsidies reached $88 billion in 2011.[2] ”
from http://en.wikipedia.org/wiki/Energy_subsidies
(This is without even considering that fossil fuel usage imposes external costs such as pollution, that the fossil fuel user does not pay. Some have argued that this amounts to an effective subsidy of the order of a trillion dollars per year).
Apart from what g_pepper has correctly pointed out regarding size/power of hydro plants…
With the right terrain, this is pretty trivial, all you need is a relatively small dam wall closing off a small ravine between mountains… here is a nice example:
http://www.iwb.ch/media/de/picdb/2012/366/nant_de_drance_stausee_vieux.jpg
http://www.iwb.ch/media/de/picdb/2012/367/nant_de_drance_stauseen_vieu.jpg