Solar3D says prototype makes light work

US technology developer Solar3D has begun fabrication of a manufacturing prototype of a crystalline silicon (CSi) cell it reckons could reach game-changing efficiencies of better than 25% by using micro-PV technology and light-management techniques from the fibre-optics industry.

Solar3D’s maiden prototype, which uses a three-dimensional design to trap sunlight inside a PV structure where photons “bounce around” until converted into electrons, produced 250% of the power of a conventional CSi cell made under the same conditions.

“When we completed our first prototype...we achieved more power, relative to current technology, than we dared to hope. As we continue our work, we have discovered a number of ways to fine-tune our process so the product will produce even more power, and be less expensive to manufacture,” says director of technology Changwan Son

Although high-grade CSi cells have a theoretical maximum ­efficiency of 33%, current technology often has conversion rates of under 20%.

This is due to the fact that a third of the sunlight may be reflected off silicon cells’ surface, and much of the energy that does ­enter the cell is lost in transit to the contact wires that complete the circuit to flow the electricity.

Solar3D’s concept reduces these losses, using “light collectors” to trap incoming sunlight and a ­patent-pending, multifaceted three-dimensional PV structure that ­allows photons to ricochet rapidly ­within a cell until their ­energy is “optimally absorbed”.

The company calculates its concept will lead to an “at least 50% reduction in the cost of solar electricity [with] installed system cost savings may be even greater”.

A pilot manufacturing run of the 3D cell is on track for later this year, with commercial roll-out in 2014, says Solar3D.