The company SunPower in 2008 announced 22% efficiency converting light to electricity. Current high-performance panels, on average, convert about 20 percent of the light that strikes it into electricity. Conventional silicon solar panels convert about 14 to 17 percent of light.
The theoretical maximum is around 26 to 27 percent, although some have said it could go slightly higher.
Reference: http://www.news.com/8301-10784_3-6114383-7.html
More solar facts.
In 2002, the following amount of electricity, in gigawatt-hours, was generated from the following sources of fuel:
Coal: 1,925,792 GWh
Nuclear: 779,461 GWh
Gas: 695,226 GWh
Hydro: 255,077 GWh
Fuel oil: 91,629 GWh
Biomass: 71,534 GWh
Other (geothermal, non-wood waste, wind and solar): 22,737 GWh
More than 10,000 homes and counting in the United States are powered entirely by solar energy.
According to the American Solar Energy Society, enough sunlight falls on the earth's surface each minute to meet world energy demand for an entire year.