Forbes: The basic and essential problem with most renewable energy sources is that their output is not continuous. Solar doesnt produce at night of course (notwithstanding those clever Spaniards who realised that shining floodlights on cells was profitable given the vast premium paid for solar electricity going into the grid over buying electricity from the grid) and wind power is famously variable even at 5 minute intervals. Its going to be very, very, difficult running an industrial economy on such sources....