A Breakthrough In Photovoltaics - Part II

Advances in solar power, specifically photovoltaic technology, come along in dribs and drabs. There are small increases in overall efficiency, with 25% being quite common today. There have been some experimental PV cells that have achieved much higher efficiencies, but the cost of producing them puts them out of the range for use in every day applications. But that may soon change.

As I wrote back in April, the use of nanotechnology might be able to boost efficiencies of photovoltaic cells up to 75%. But they are still in development and not likely to be commercially available any time soon.

But someone else has taken a different approach that has already improved efficiencies to 40%. (Registration required).

A team of engineers at solar cell manufacturer Spectrolab has produced a photovoltaic system with a record-breaking conversion efficiency of 40.7%.

The solar cell, made from gallium arsenide grown on germanium, is said to offer the highest efficiency of any type of solar photovoltaic device yet produced. For comparison, the efficiency of silicon solar cells -- which currently dominate the photovoltaic market -- is typically less than 20%.

The new result is the latest in a series of record-performance cells produced by Spectrolab over the past five years, and was made possible by an improvement in conversion efficiency within the company's metamorphic photovoltaic structures. The US National Renewable Energy Laboratory (NREL) has verified the milestone.

The technology doesn't use exotic manufacturing techniques. Instead, these PV cells could be made using existing facilities that already manufacture gallium arsenide semiconductors (photodetectors and low noise microwave transistors and integrated circuits).

If efficiencies and cost per watt can be brought in line, then solar generated electricity will become a more attractive alternative, allowing its use in more places.

Frankly, I wouldn't mind being able to disconnect myself from the grid yet still have plenty of power available when I need it. Even though there are a number of residential solar cell and wind generating solutions out there, they aren't where I want them to be, either efficiency- or cost-wise. These new PV cells are certainly a step in the right direction.