Renewable Energy Sources and the end to fossil fuels

Climate change and carbon emissions, along with the inevitable fact that fossil fuels cannot provide the world’s energy forever has driven the search for renewable energy sources. Depending on the location and resources, hydroelectric, wind, biomass, geothermal, tidal, or solar could be used as a source of energy. Although no single renewable energy source is the key solution, a transition to renewable energy is necessary. Each form has its advantages and disadvantages, but it seems well known and agreed upon that fossil fuels cannot last forever so other options are needed. What I find most interesting is how individual countries have answered the challenge of renewable energy.

This link proves very interesting in how countries responded.http://cleantechnica.com/2013/10/05/insight-progress-fossil-fuel-transition/

The article and the above picture show how countries are facing the challenge of moving away from fossil fuels and how some have even achieved 100% of their energy coming from renewable energy sources.  I find it inspiring that some countries are independent of fossil fuels, which seems like an incredible feat knowing that these renewables have a large energy potential but storage seems difficult. I would like to have seen the percentages of other countries, like the United States, because it seems like most of the countries on this map are smaller countries. I wonder if the larger “power-house” countries could learn from the actions of these countries that have achieved success with renewable energy sources. Instead of only having a portfolio standard for change, I wonder how long it will take to implement change in more populated countries. It would also be interesting to see how long this independence from fossil fuels can last because of energy storage. My chief question is: how sustainable can renewable energy be without better forms of energy storage being implemented and commercialized?