Sometimes a simple observation by a thoughtful person can lead to the invention of an important environmental product. This happened in 2003 when a commercial flower grower in California was checking the flowers in his fields at night. His name was Pieter Hoff. Pieter noticed that droplets of dew on leaves (which we all associate with the early morning) actually collect on those leaves well before midnight. The reason this happens is, of course, that plants lose heat to the air at night and water vapour condenses as droplets of liquid water on the cold leaves. Some of this water may be used by the plant, but much of it evaporates as soon as the sun rises.

Hoff began designing devices which would give a plant a greater surface area than its own leaves to capture water. After trying many prototypes, he came up with a design for a plastic planter box which is circular and about the size of a car tyre. It has zig zag plastic flutes which radiate around the plant stem. The flutes are tapered downward and inward so that condensed water runs down around the plant stem and into a holding tank. Any rain that falls is also collected in the tank. The collected water then drips into the soil, providing moisture for the roots. Pieter Hoff calls this plant incubator the Groasis Waterboxx.

In 2006, Hoff tested out his Waterboxx in the SaharaDesert in a tree-planting project. Half the trees in the experiment were watered once a week, while the other half were surrounded by Waterboxxes and not watered artificially. After one year, 90% of the trees watered weekly had died, while 10% survived. In the Waterboxx group, only 12% had died, while 88% survived. The Groasis Waterboxx has tremendous potential for arid areas.

So far, Peter Hoff has spent more than $7 million developing his brilliant invention. It has been a long, hard slog and he's still looking for partners. You can find out more about this invention at www.groasis.com For what has been achieved so far, the Groasis Waterboxx deserves to be called the Energy Efficiency Product of the Week.