Fact or fiction - cheap solar energy?

Now that the N word has put a scare among public and governments, maybe it is time to work hard on the renewables. And thinking of renewables in summer, one looks up to the sun!

The sun strikes every square meter of our planet with more than 1,360 watts of power. Half of that energy is absorbed by the atmosphere or reflected back into space. 700 watts of power, on average, reaches Earth’s surface. Summed across the half of the Earth that the sun is shining on, that is 89 petawatts of power. By comparison, all of human civilization uses around 15 terrawatts of power, or one six-thousandth as much.

In 14 and a half seconds, the sun provides as much energy to Earth as humanity uses in a day. In 112 hours – less than five days – it provides 36 zettajoules of energy –as much energy as is contained in all proven reserves of oil, coal, and natural gas on this planet.

Isn't that reason enough to harness that energy? Yet solar power is still a miniscule fraction of all power generation capacity on the planet. There is at most 30 gigawatts of solar generating capacity deployed today, or about 0.2 percent of all energy production. Well, there is the cost. But...

Increasingly, there is a thought among experts that we could be witnessing a Moore's Law in the solar energy field. We would eventually have the solar equivalent of an iPhone – incredibly cheap, mass distributed energy technology that was many times more effective than the giant and centralized technologies it was born from.

The National Renewable Energy Laboratory of the U.S. Department of Energy has watched solar photovoltaic price per Watt of solar modules (not counting installation) drop from $22 dollars in 1980 down to under $3 today. If the 7 percent decline in costs continues (and 2010 and 2011 both look likely to beat that number), then in 20 years the cost per watt of PV cells will be just over 50 cents.

Conclusion: Solar capacity is being built out at an exponential pace already. The exponential trend in solar watts per dollar has been going on for at least 31 years now. If it continues for another 8-10, which looks extremely likely, we’ll have a power source which is as cheap as coal for electricity, with virtually no carbon emissions.

Any arguments?