Swanson’s Law and the Stunning Drop in the Cost of Solar Cells

Fracking, as I have written, may allow natural gas to be a bridge fuel solar. And the above chart shows the price declines in photovoltaic cells, kind of an action shot of Swanson’s Law, the clean energy version of Moore’s Law. As explained by The Economist:

Moore’s law suggests that the size of transistors (and also their cost) halves every 18 months or so. Swanson’s law, named after Richard Swanson, the founder of SunPower, a big American solar-cell manufacturer, suggests that the cost of the photovoltaic cells needed to generate solar power falls by 20% with each doubling of global manufacturing capacity. The upshot (see chart) is that the modules used to make solar-power plants now cost less than a dollar per watt of capacity. Power station construction costs can add $4 to that, but these, too, are falling as builders work out how to do the job better. And running a solar power station is cheap because the fuel is free.

Energy storage — for the sun does not always shine — remains a hurdle, but they’re working on it.