Passive Solar Tower Power

Tonight, I watched a pretty good cable program on the History Channel, "Environmental Tech II." It was billed as discussing inventions with potential "for holding off...global warming" and though I haven't run numbers to allow comment on that claim, I did find one statistic interesting.

A solar tower concept proven in eco-friendly Spain during the 1980s was nothing more than a big greenhouse of plastic sheeting surrounding the base of a giant chimney, allowing air to be drawn in at the margin of the plastic roof, be heated by the sun, and drawn up the 430 foot wide concrete pipe to be emitted a kilometer up in the sky. In reviewing the proposed EnviroMission supersized 200-mW solar tower, the television show stated that 620 similarly sized towers could power the electrical needs of all US households. The cost of the first such tower in Australia was reportedly expected at 700 million US Dollars.

$0.700 billion x 620 towers = $434 billion.

So, once again, for less than the cost to date of the second, and completely unnecessary or even ruinous Iraq war, according to this show's assertions America with available and rather low technology could have already freed its homes completely from dependence on fossil fuels for electrical generation.

Can this be true or is this another over hyped claim typical of these kind of popular programs?

Let's see, 200MW x 620 = 124 gW of power. This is similar to the EIA figure of 122,471,071 end customers in the 2006 residential sector, but they directly consumed 1,351,520.036 gigaWatthours of electricity that year.

So average US residential end user electric billpayers consumed 1,351,520.036 *1,000,000 / 122,471,071 = 11044.441 kWh per year = 920.370 kWh per monthly bill.

And 1,351,520.036 / (365.25 days * 24 hrs) = 154.177508 gW of net internal demand which we must increase by the 16.1% overhead of marginal capacity in 2006. The actual figure in 2006 of electrical capacity claimed by the residential sector in the US may then be stated as 179.0002 gW, equivalent to 895 big solar towers, costing $626,500,618,758.

Hmmph, still less than the cost through 2007 of the Iraq war! And the money would have been spent over here on good jobs like cement and steel construction, and thereafter tourism and commerce...imagine architecturally what could be hung at the top of those gigantic towers! Oh the unimaginable blast of music an organ could produce with only a small siphon of the slipstream ascending! That's the kind of world I'd really be excited to help create!