3D printing in the desert

From the article:

The Sun Cutter focuses sunlight using a fixed ball lens, while cams on a solar-power-driven timing belt control the motion of a platform on which the raw material sits. The current incarnation of the Sun Cutter can cut paper, card, and plywood up to 0.4mm thick, and cuts out the frames of a cute, clever pair of sunglasses. How's that for meta? Meanwhile, the Solar Sinter uses a different--and more easily acquired--feeder material than most other selective laser sintering (SLS) printers. Instead of powdered resins, plastic, or metals, the environmentally friendly 3D printer uses sand, plain old silica. Light collected from about two square meters of Fresnel lenses heats the sand above its melting point (1500 degrees C); once it cools, it solidifies into a solid chunk of glass. Kayser himself acts as the material dispenser, smoothing layer after layer of sand onto the melting platform. The final product isn't as finely-resolved as one built using an SLS printer, but on the other hand, you'd be hard-pressed to run an SLS printer in the Sahara desert.