We've made great progress with renewable energy -- but from an almost zero base we still have a long way to go. Fortunately, the path is clear. California is already over 12% with a combination of hydroelectric, wind and solar (unfortunately not much hydro this year). Getting to 50% only requires the deployment of existing technology. But can we get to 100%?

It depends on whom you ask. Our society has made these transitions before, with new energy technologies disrupting the incumbents. 200 years ago 95% of our energy came from wood; by 1900 it was 50% coal; and by 2000 it was a mix of coal, nuclear, oil and gas. The Union of Concerned Scientists have published a plan for renewable energy to provide 80% of our electricity by 2050. Why stop there? Solar enthusiasts like me want to go for 100%.

This goal is possible: there is a recent Stanford paper entitled “100% Wind, Water, Sunlight (WWS) All Sector Energy Plan for the 50 U.S. States.” This plan is surprisingly realistic when one considers the rapid rate of solar deployment coupled with storage and new energy control technologies such as demand response and dynamic energy pricing. Costs are not the problem because these these technologies are being deployed now. The real issue is political will -- and incumbent energy supplier resistance. Listen up to this weeks Solar Energy Show as we talk about the practical steps we need to take to get to a society powered 100% by renewable energy.