The German government would be making a much more effective global statement if it invested the resources it is putting into photovoltaics much more heavily into its (and European Union) foreign aid programs.

How many struggling communities in areas of the third world with MUCH better solar statistics for photovoltaics would benefit from such German investment?  The power generation of cells put into remote areas of Niger, Sri Lanka, India, etc ... would be significantly higher than what happens in Germany.  

Use these 'markets' as the incentive to push forward the German market place and strength in solar programs.

This would have a better effect long-term on helping developing nations develop along responsible paths and toward attacking global warming than putting major solar plants in Germany -- where it will generate a fraction of electricity per cell compared to what would happen elsewhere.