From: ChemE Stewart
I can slap in a 50 MW peaking solar PV field in a couple months for 1/2 the price and a year and 1/2 faster than a solar thermal plant. Obsolete technology. Period That is very short sighted. It ignores the inevitable progress and the vast possibilities for synergy in the next generation. In fact, this particular technology is not far from the cutting edge, if a relatively simple upgrade can be implemented. They - which includes Google - are already talking about the next generation of concentrated solar. It is called CPVT. The same heliostats, or the same collector surfaces - which are installed in the Mojave site, or preferably a smaller site - could even be used but with a twist. If you can slap a PV field together in a couple of months then a hybrid PV panel can be slapped onto existing mirrors in a couple of weeks, and R&D is already underway to do this. Alternatively, high temperature PV panels are placed over the collector exterior. Both of these require a different kind of PV cell which skims off photon spectra - one can be high pass and the other low pass; and then either reflects most photons or absorbs them. In fact the PV can be added to both mirror and collector of concentrated solar thermal. The hybrid technology is called CPVT and it can employ an existing mirror rendered partly reflective since the modified PV panel is located on the mirror, or as the covering for an existing collector it will permit thermal transfer. In some cases the PV part will be less efficient than normal PV, but a large fraction of photons are reflected and concentrated. Synergy exists, since you get the free heliostat steering (sunk cost) of the existing mirrors. Here is a CPVT version for parabolic troughs which is already in place. http://chromasun.com/images/content/papers/Initial%20field%20performance%20o f%20a%20hybrid%20CPV-T_May2012.pdf Here is an CPVT system for distributed (home) use. Makes perfect sense since very hot water for home heating is essentially free. http://solvarsystems.com/company/index/items/27 Here is a bibliography that focuses more on the non-concentrated version, which is called PVT. http://www.hindawi.com/journals/ijp/2012/307287/ref/ There is nothing obsolete about concentrated solar thermal as the first step towards a hybrid, especially as it progresses to CPVT. However, it should be perfected for distributed cogen systems first IMO. Unfortunately Google is not very interested in the distributed option.
