A report released by NREL on March 26, 2013 concludes that 80% of U.S. Electrical generation could come from renewables in 2050 based upon the use of technologies that are available today.
This report does mention that it is only “technically feasible” and that many issues remain to be resolved. My response would be that it is also “technically feasible” to launch a huge mirror into space and direct additional solar energy towards an earthbound receiving station. It is also “technically possible” to produce energy using nuclear fusion today, albeit for only about 0.5 seconds.
There is a big difference between something being technically feasible and believing that it will actually happen within the next 100 years or so. With all due respect to the scientists at NREL I don’t think that it is too difficult to demonstrate that it IS NOT possible to generate 80% of North American electricity demand from renewable sources using currently existing technology. New energy storage technologies will have to be developed and a very different and more holistic approach to many different components of our use of energy will be required in order to achieve this goal.
I have provided a more detailed analysis in my latest posting at The Black Swan Blog
By the way – happy Earth Day – I am a believer!