Massive Solar Updraft Towers Planned For Arizona

MikeChino writes "Australia-based EnviroMission Ltd recently announced plans to build two solar updraft towers that span hundreds of acres in La Paz County, Arizona. Solar updraft technology sounds promising enough: generate hot air with a giant greenhouse, channel the air into a chimney-like device, and let the warm wind turn a wind turbine to produce energy. The scale of the devices would be staggering — each plant would consist of a 2,400 foot chimney over a greenhouse measuring four square miles. The Southern California Public Power Authority has approved EnviroMission as a provider, although there’s still plenty of work to be done before the $750 million, 200 megawatt project can begin."

Comments

I can't help but wonder...

[Rei]

these couldn't be built for a small fraction the price by using an atmospheric vortex engine instead of a tower.

Re:Nuclear Would Use Less Land with Higher Output

[QuoteMstr]

How big are uranium mines, the roads used to transport the uranium, the refining plants, the reprocessing plants, and the mountain that is needed to store the waste for several millenia?

Well, let's see. Coal has an energy density of about 24 megajoules per kilogram, and uranium has a density of 560 megajoules per kilogram. Uranium comes from its ore uraninite, which is UO2 (78% uranium by weight). So let's adjust uranium's energy density to 441 megajoules per kilogram to make up for it.

The density of coal is about 1.05 g/cm^3, while the density of uraninite is 8.725 g/cm^3, that is, uraninite is 8.3 times denser than coal on a weight basis. It also has 18.375 times as much energy.

So, taking into account both the higher density and higher energy density of nuclear fuel, we need 1/(8.3 * 18.375), or 1/152 the infrastructure we need to mine the equivalent amount of coal.

Let me repeat that: for the same amount of energy, we need 153 times as much infrastructure to get it from coal instead of uranium.