solar towers offer up to 20 times more power output than traditional flat solar panels. Two small-scale versions of three-dimensional photovoltaic arrays that were tested by MIT researchers (Photo: Allegra Boverman) .
Wattle and daub is one of the oldest building techniques dating back to the Bronze Age and beyond. Wattling is a way to build walls by weaving long flexible sticks in and out of upright posts. Hazel, which is pliable and grows naturally long, is a good sp