Solar Efficiency?6

After doing some research on press releases in the past six months I've found an overwhelming amount of information on new world records for solar efficiency.

For example, a Chinese company named Suntech Power Holdings announced last august that they have broken the world record for solar efficiency with their polycrystalline silicon PV module of 15.6%. Not long after that in October the California based company Solarmer announced that they were able to improve the solar efficiency for plastic cells to 7.6%.

Then this year in Febuary IBM announced a 9.6% efficiency for solar cells composed of other low cost materials such as zinc, sulfur, selenium, etc. The biggest news, however, was the news that Sharp announced late last year that they have achieved a 35.8% solar efficiency through compound solar cells (the same ones our satellites use)but it is far from commercially viable.

So probably for most of us and definitely for me this is increasingly confusing as to what is the number we should be thinking of when we want to find a standard to either reach for or test our own against?