PV is more expensive than wind... yet iirc, aren't small wind generators (say for cabins, boats, etc) still more expensive than comparable PV panels...?  maybe I am remembering wrong -- must check some real catalogue prices to confirm this, but my imperfect memory from a wee bit of shopping around was that flexible marine-grade solar panels were "getting affordable" but wind generators of decent quality were still "very expensive" and I was discouraged from buying into the technology (aside from that there was the challenge of balancing the blades, constructing a tower, etc.)  I will try to do some actual wH comparisons and see what the customer is really paying for.

The difference between theory and practise in practise ...

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.

Indeed PV is much more expensive now. The lowest I have seen is 25 Eurocents/kWh over 20 years, and that was a MW-scale project - private units are more like the double of that.

For scale, here are the German feed-in tariffs for 2004:

capacity	< 30 kW	30 kW << 100 kW	100 kW <
field		45.7 c/kWh
rooftop	57.4 c/kWh	54.6 c/kWh	54 c/kWh
other building-integrated	62.4 c/kWh	59.6 c/kWh	59 c/kWh

Except for the 5 c/kWh bonus for building-integrated non-rooftop (e.g.: windows, walls) units, for new units these tariffs are reduced every year by 5%, thus for example this year:

capacity	< 30 kW	30 kW << 100 kW	100 kW <
field		43.42 c/kWh
rooftop	54.53 c/kWh	51.87 c/kWh	51.3 c/kWh
other building-integrated	59.53 c/kWh	56.87 c/kWh	56.3 c/kWh

_{*Lunatic*, n.
One whose delusions are out of fashion.}

To my knowledge, they don't need much maintaince - even less than wind (no moving parts), only the replacement of batteries if present. In Germany, they are usually expected to last 20 years - that is, price calculations run roughly like:

(construction & installation costs) / (20 x (expected yearly production) x (feed-in tariff))

(See some data on this in my upcoming reply to Jérôme.)

As far as I know, the only significant problem with time is chemical changes in the semiconductor, which bring down the efficiency over time.

_{*Lunatic*, n.
One whose delusions are out of fashion.}