10,000 X less semiconductor material needed for equivalent energy output. Vertical nano-wire design:
“Anna Fontcuberta i Morral and her team built a nanowire solar cell out of gallium arsenide, a material which is better at converting light into power than silicon. They found that it actually collects more light than the usual flat solar cell–up to 12 times more–and more light means more energy.
Also, arrays of nanowires would use at least 10 000 times less gallium arsenide…”