To most people solar energy seems like the best possible renewable energy option because Sun is the most abundant form of energy available on our planet. The major problem with solar energy is the fact that solar power technologies are still very expensive, even despite the recent decline in prices. Solar energy is also an intermittent source of energy because sunlight isn't available all the time, and is therefore in need of some cheap energy storage solution.
World will eventually fully go solar, and solar energy will rule the world in years to come, if not for anything else then because fossil fuels will eventually be depleted.
The Sun should shine for approximately 5 more billion years, more than enough time to harness solar energy on much wider scale :)