Large solar thermal plants on desert wilderness land to power obscenely wasteful cities like Las Vegas?  Not a good idea, put them on factory roofs, or already devestated industrial sites instead.

http://gristmill.grist.org/story/2008/3/6/72549/02694/#comment7

Storage

From this NYT article:   

http://www.nytimes.com/2008/03/06/business/06solar.html?pagewanted=1&_r=1&hp

"He was trying to produce as much electricity as possible while saving heat to tide the plant over as clouds cast episodic shadows on the solar array. "I've been fighting it all day," he said."

This is what storage does.  The hot oil melting wax, for instance, would bridge the cloudy gaps.  Stabilizing the output.

The better, cheaper design that Google is funding melts salt at a much higher temperature.  Mirrors direct the solar energy to a tower where it is collected to melt the salt, then the water is boiled from the heat stored in the molten salt.

Allowing longer term storage, 6 hours it says in the times article, with evacuated insulation like a thermos bottle.

Transporting the heat with hot oil over a square mile is inefficient.  With the tower method the light itself does the transportation, focused on the central tower.  The older technology heating oil with trough collectors is obsolete already.

The solar tower energy system should not be done on wilderness desert land, it should be located on factory roofs or on land already destroyed by industrial or mining use.  

A portion of the revenue generated by the solar syatem should be used to rehabilitate these sites back to natural conditions.  Industrial sites and factories will already have power lines nearby.

The mirrors in the tower system have a very low impact on the land, unlike this trough system in the Times article.

Concentrating solar PV and heat cogeneration mounted on rooftops will already compete with the tower system on cost per kwh and the power can be stored as heat or cold with geo heat exchange heating/cooling.  A 10 cent per kwh subsidy direct to homeowners for these systems would make it beat this technology to mass production and adoption.

the solar tower technology is not something to subsidize heavily, let energy intensive industries use it on factory roofs and over parking lots.  

And use the solar furnace heat directly for heating production materials, then cogenerate electric power from the waste heat as the molten material cool.  Glass and metal recycling and silicon refining would be good industrial uses for this scheme.