In the right locations it should be possible to build solar towers at a very low cost per kW. The right location consists of a south facing mountainside in a sunny location. The mountain almost entirely eliminates the structural support problem, and the south facing mountainside should offer better solar collection than a flat surface. The cross sectional area could affordably be very large. Given that rise would exist in the mountainside solar collector, the base would thus serve a dual purpose as heat collector and rise column, and funnel up to a purely rise column. A steep mountainside should make for less expensive real estate as well.
The above applies to the northern temperate zone. In the southern temperate zone a north facing mountainside would be the right location. In an equatorial zone multiple faces might be used for solar collectors, possibly with rise columns located on multiple sides of a mountain. Regards, Horace Heffner
