And some designs provide power round the clock, not just when the sun is shining, by storing energy in the form of molten salt.

ECONOMIST: A new type of power plant harnesses the sun��and taxpayers

To use that excess electricity (obviously, only excess when the wind is blowing just right, or the Sun shining) to electrolyse water by passing it through a fuel cell and then store the resultant hydrogen.

FORBES: Apple Wrongfoots Greenpeace over Renewable Power for the iCloud

Who does that, who pours people drinks at eleven in the morning when everyone is just sitting there baking in the sun?

NEWYORKER: Brother on Sunday

Just when the snow is gone and the sun is warming things up, the black flies appear.

NPR: Waging a One-Woman War Against Black Flies

With most major economies in East Asia suffering their deepest recessions since World War II, brave is the forecaster willing to say just when the sun will come out -- and how strongly it will shine.

CNN: THE LONG, HARD CLIMB BACK UP