These two charts, from ILSR, show the rapid progress of solar and wind power in the US. In 2013, the two combined formed 28% of new installed electricity generation capacity but in the first half of 2014 this doubled to 56%. To get to 100% we will need battery costs to fall a bit further. But already battery peak power (draws from the grid off peak, and releases it back to the grid at peak) is comparable in cost (in the US) to gas-peaking power. Battery costs are falling precipitously. Within 5 years it is very likely that all new installed power sources in the US will be renewables. And as old power stations are decommissioned, they will be replaced, not by new coal-, oil- or gas-fired power stations but by renewables.
Disclaimer. After nearly 40 years managing money for some of the largest life offices and investment managers in the world, I think I have something to offer. These days I'm retired, and I can't by law give you advice. While I do make mistakes, I try hard to do my analysis thoroughly, and to make sure my data are correct (old habits die hard!) Also, don't ask me why I called it "Volewica". It's too late, now.
BTW, clicking on most charts will produce the original-sized, i.e., bigger version.