Solar Towers was How many SPSes for $87 billion ?

Just been catching up on some reading and got to this post.
you might want to take a look at
http://www.enviromission.com.au/

which is a company that is going to build one of these towers in Australia.
There has been smaller towers built, including one in Spain that has run
for several years, but this will be the first full scale one.

Brett