30 to 40 years ahead of what the IEA forecast in its 2014 Solar Technology Roadmap.
50 to 100 years ahead of what the IEA forecast in its 2010 World Energy Outlook. (Depending on how one extrapolates IEA’s forecasts from 2010. Indeed, it’s also possible to interpret the IEA’s 2010 forecasts as to say that solar electricity is now cheaper than the IEA thought it would ever be, back in 2010.)
In short solar prices have dropped faster and lower than almost anyone has expected.
From the article: