Hello,
The cost estimate from the Scientific American "Grand Solar Plan" (which was to provide 69% of all our electrical needs) was just 420 billion. Not too much really.
That is for ~30,000 square miles of mostly photovoltaic panels, with some solar heat collection (which I prefer), high voltage DC transmission (very efficient apparently -- only 10% loss from coast to coast!) and it included underground compressed air storage to cache excess power, which then provides power when the solar systems are not producing enough. Also, a large company recently released some details about a system that used molten salt to hold high heat (1100F) for a long time, so overnight generation from solar heat plants is doable, if not for longer.
Here's the article (though they have pulled the nice images that were in it at the beginning):
A Solar Grand Plan: Scientific American
They were shooting for 2050 -- quite a bit longer than what Al Gore is proposing.
If we were to combine this "grand solar plan" with what Lester R. Brown proposes in
Plan B 3.0 -- which is to build 1.5 million 2MW wind turbines (using some idled assembly lines?) by 2020; to replace ALL the coal fired power plants! Again, not quite as fast as what Al Gore is proposing -- but the coal plants are also about 70% of our electricity; and they are by far the worst offenders in carbon dioxide output.
And
T. Boone Pickens seems to agree.
If we add in geothermal deep drilling, and/or wave power along the coasts (or offshore wind power!), then I think it is doable -- and trying is everything! We will see immediate benefits! And as Al Gore points out -- we will see huge improvements on three fronts all at once.
The savings from scaling back (and stopping?) the Iraq War alone could
easily pay for this.