"Admits" seems a bit harsh, like he was doing his best to hide something from the world.<p>By all accounts, it looks like he had written out a reasonable explanation as to why he predicted solar would not become cost effective. At the end of the day, if something doesn't make financial sense, it won't last long without subsidies from the government.<p>The assumptions behind his predictions changed and therefore so did the conclusion. Seems pretty reasonable.<p>Like he says, solar power's intermittency is still an issue in non-sunny places, but in areas with lots of sunlight, the landscape of power generation is changing for the better.