Well, happy new year. It's busy around here - you're best going to Dylan's weblog for the real news... meanwhile, this caught my eye.

An Australian power company plans to build a kilometer-high tower as part of a solar power station. The engineering behind this is really cute: big flat greenhouse; vertical tube in the middle; hot air rises and drives a turbine. The higher the "chimney", the more efficient your power plant.

The designers' website includes this provocative statement (my emphasis):

Solar chimneys predominantly consist of concrete and glass which are made from sand and stone plus self-generated energy. Consequently in desert areas - with inexhaustible sand and stone solar chimneys can reproduce themselves...