"By some definitions, nuclear energy is 'alternative.' By others, it is not. Specifying things directly, I will say that wind, solar, solar/thermal, solar/thermal/electric, biomass, hydro --- all forms of solar combined can not replace coal, oil, and natural gas.
Geothermal energy is essentially limitless, but by and large is way too deep in the ground to be practicable.
Nuclear energy is essentially limitless, and could easily replace fuels used for heating and electricity production. It could not easily replace fuels for transportation.
Now, if you boil that down to one word, is it pro or con?"
1. Is Solar Power Production Environmentally Friendly?