The big problem is that every technology has a downside. Solar requires large areas of land; hydro requires us to block off rivers; coal pollutes; oil... also pollutes; nuclear is the biggest target of NIMBY-ism I can think of; geothermal is expensive and hard to do properly.
We can't magically fix our energy problems. There is only so much energy capacity in the world. We can only build so many solar panels, so many hydro plants, so man coal or oil plants, so many windmills. The better solution to fixing our energy problems is for us to look into increasing efficiency of existing technologies, using them where necessary, and reducing our energy consumption in general. If our consumption continues to grow, we will eventually be unable to generate enough to power all our stuff.
Seriously, does grandma, who only watches youtube videos of the kids and e-mails her bridge club, need a PC that draws 700W? Does Uncle Bob really need a 63" LCD display when his whole apartment is 10 feet wide? Do we really need to *drive* to the grocery store for a gallon of milk when it's actually quicker to get there by bike?
We can save a *lot* of energy -- and money -- by thinking about our choices.