Thank you for an excellent post.

Another issue with PV solar little noted is that they wear out.

The electrical output starts declining as soon as they are used (rate is related to heat exposure I believe).  Earlier models were at well less than half output in a typically application in 20 years.  Don;t know about latest versions.

Still, not a permanent solution.

How many atomic breeders do work succesfully in the world? There was really a lot of research and money for this technology.

OK, photovoltaic cells are - for the time being - a more cost intensive energy source. I agree with you. However already today, where is no electric grid, it is already cheaper. Especially in these rural areas, many people still depend on kerosene lamps or generators for light or electricity.

Even energy predictions from companies like Shell show in 50 years a very large percentage of solar energy in use. Writing off is as far as I can tell much to early!

Another way to harness solar energy is here

Solar Power for the Global Village

Jürgen Kleinwächter has developed a model for solar energy supply to an African village with 50 inhabitants, the "Solar Power Village". Without photo voltaic it produces energy for cooking, pumping water, wheat milling and electricity.
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Under the roof of a 30-40 sqm sized green house - this size may not be adequate for European conditions - a row of fresnell lenses are mounted and follow the movement of the sun. The fresnell lenses focus the sunlight on a focal line. Exactly in this focal line vegetable oil flows in blackened copper tubes that are coated by transparent glass tubes. Kleinwächter: "Vegetable oil is available everywhere in the 3rd World. Here the oil serves as a carrier of heat. As the oil flows through the concentrated energy zone it heats up easily to 220°C."
The green house is covered by a special layer. This allows more parts of the sunlight spectrum (especially UV) to pass through than usual layers do - supporting the growth of vegetables underneath and making the layer last longer. "By the way, the vegetables are of a very good quality - you can not compare it with the usual products from green houses", Kleinwächter declares. "The temperature in the green house is as comfortable as a day in spring, and allows the growth of salad even in the summer."
The special layer belongs to the few parts of the Solar Village that can not be produced in regional work. From the green house the oil then flows into a heat storage.

Not so fast, The National Renewable Energy Laboratory has been working with 'quantum dots' of Lead Selenide. According to the article at:

http://www.nrel.gov/news/press/2005/1805_quantum_dot.html

the lead selenide quantum dots they are working with could theoretically acheive a 65% conversion rate. The best silicon cells are at 21.6% and use a positive ground. Roughly a factor of 3.

Dr. Nate Lewis of Caltech has been crunching the numbers with respect to quantities of primary fossil fuels, oil, gas and coal. He's compared various alternatives and what they would mean to area useage such as the area to grow ethanol from corn to replace all 3 types of fossil fuels. Around 57 minutes in, he calculates how much PV it would take to replace all three. Interested? Here's the URL:

http://online.itp.ucsb.edu/online/colloq/lewis1/

I calculated that I could carpool, on average, 30 miles round trip every other day and power the trip using PV from my roof.