The solar game is all about the numbers. Before you buy panels for your roof, you do the maths - how much? How long to pay off? Can power prices really keep increasing?
On a broader scale, power utilities are also furiously doing the maths on the solar equation. Will there be mass uptake? Is this really a solar boom, or a flash in the pan? Just how low will panel prices drop?
The first lot of questions are straightforward. The second are harder to predict, but early indications are that any forecasts will be so undercooked as to be comically so.
The estimate made in 2000 that by 2010 global solar installations would reach no more than one gigawatt proved to be incorrect by a factor of 17.