Let there be no doubt that strong renewable energy policy and political commitment led to this. This is a political and cultural choice, not just the market left to its own devices.
New stats from the European Union Joint Research Centre show that Europe installed 18.5 gigawatts of solar photovoltaics in 2011—two-thirds of all the solar panels installed in the entire world—bringing total solar PV capacity to 52 GW.
Two thirds of the global investment in solar PV was also concentrated in Europe, totaling roughly €65 billion ($84 billion).
For the past decade the solar PV industry in Europe grew at an average of 40% annually (for the world it's 40-90%), with production costs dropping 60%, the report says. China remains the largest producer of solar power products in the world, with 50% of the market for solar PV.
As an indicator of how much more needs to be done for Europe to hit its goal of using 20% renewable energy by 2020, solar power currently produces just 2% of total electricity demand in the region—though obviously wind power and other renewable sources will also contribute to this goal.