It is surprising that IBM would make a comment that they "don't plan to make [concentrated photovoltaic] systems", given that the two technologies have much in common :
- both require thin-film substrates of silicon
(either amorphous, poly-crystalline or mono-crystalline)
- both utilise nano-scale features (see http://www.technologyreview.com/Energy/19696/,
http://www.technologyreview.com/Energy/18415/ and
http://www.technologyreview.com/read_article.aspx?id=20163)
- both employ multiple layers of various materials (semiconductors and metals) to act as electrical pathways and improve efficiency

I would have expected there to be enough complementary overlaps in manufacturing techniques that there are significant benefits to incorporating the two technologies within the same development environment.

I'm concerned that the latest thin film and concentrated PV rely on some scarce minerals like, Cadmium, Indium, Gallium, Selenium, Tellurium, and so on. Reserves of some of these metallic elements are numbered in mere tons. They already have uses in the electronics industry that could potentially consume them. So, how far can we really stretch them for use in solar panels? Probably not nearly as far as we imagine. Costs come down and use of materials goes down, but in the end, can we achieve the potential of solar by relying on these scarce materials?

For this reason, I am most impressed by technologies that move Silicon PV cells forward. We have Silicon in great abundance. Efforts to bring down costs of Silicon production, reduce waste, improve its quality and to use far less of it to produce the same or more energy deserve the greatest attention in the long run. When combining the best of the latest innovations, it seems certain that Silicon-based cells could compete on cost.

After a little research, I found the following paper online. Here's one of its conclusions:

"Today it appears unrealistic to expect that a PV system based on either CdTe, CIGS or
ruthenium-dye-sensitised cells could produce more than 10 000 TWh/year
corresponding to some 6 TWp in the year 2100 and an average growth of 60
GWp/year sustained over 100 years. According to most energy scenarios this would
correspond to less than 5% of the total energy supply. A potential that is a factor of
ten lower is perhaps more realistic, that is significantly below 1% of energy supply.
Amorphous silicon, with germanium, is much less constrained, and without
germanium it is not material constrained, in our sense, at all."

http://frt.fy.chalmers.se/PDF-docs/BA_thesisWoP.pdf

The heat from collector systems can be extracted to generate power via low pressure (wet steam) or it can be used to heat salt beds for later extraction at night (see Nevada Solar 1).

There are ways to take the heat and increase the velocity of the fluid via orifice or venturi for extraction by a low pressure steam system to drive an auxiliary generator. It's a sound principle that is currently used in today's co-generation power plants. Use the exhaust heat of a gas or coal fired engine to drive a secondary low pressure steam system.

The remaining or residual heat can then be dumped to atmosphere using cooling vane technology. Sometimes the best solutions are old tech.

Can the technology being developed to produce electricity from waste heat in internal combustion engines with thermoelectric [paint] materials in exhaust (pipes) be used to enhance the production of electricity in photovoltaics? It seems a shame to just waste all that heat!  When can we expect an inexpensive photovoltaic system for home use which can compete with the local electric utility?