The spam filter was preventing me form posting this, probably due to the links, and I put work into it and don't appreciate that so I'll post it here instead so it doesn't go down the memory hole, fortunately I always copy my comments to clipboard before submitting so it is easy to reproduce:

"does anyone else share this critique?"
I sort of do. I may sign up on the wiki as a collaborator when I get around to it, and I can volunteer to do a time step simulation in calc if I can get the relevant data table for efficiency vs. input temperatures etc. or better insolation vs. efficiency for the engine it is easy to take weather data (includes insolation measures) from NOAA or elsewhere and produce a time step simulator to determine the detailed anticipated kwh output on an hourly basis for a whole year (or multiple real years even). This can then be compared with other systems in the same way.

What the ideal way to do things is to do the simulation (hypothetically to very high accuracy but the weather data is only hourly anyway and that's not bad) then compare to what's called a "demand pattern" to represent the demand, and compare them for different systems. I think typical demand patterns are available. Thus inching closer to total system optimization.

Also Abe is right about the solar prices. Here is a reference:
http://www.gpsolarpanels.com/
http://www.ecobusinesslinks.com/solar_panels.htm

The first one has them supposedly at $1.2 per watt. Also I posted a comment on this blog already linking to an idea to get roughly twice to 2.5 maybe more energy per day out of a solar panel with the use of a variable concentration ratio solar collector. By my reckoning the cost maybe reduced by 80% or so after the cost of the collector. This is drawn from time step simulations in calc, you can download an view the spreadsheet and verify this if you wish:
http://towardsabettertinyhouse.wordpress.com/2011/01/28/much-cheaper-photovoltaics-part-1/
http://towardsabettertinyhouse.wordpress.com/2011/01/30/much-cheaper-photovoltaics-part-2/

The sunlight is substantially less intense here, and unlike for solar panels, the output of a heat engine system goes down faster than the solar input does (less efficient at lower insolation) which is less of a problem for solar panels.

By the way the reprapmetallica people are looking into producing their own thin film panels with a vacuum chamber at home. I don't know if this can be done without rare metals though.

So if this system is to compete on the open market it will have fierce competition... I posted in the forum about linear free piston engines. Infinia is now competing with solar panels successfully with LFPS engines and dishes so there may still be hope for solar thermal electric if done cleverly, but I am very skeptical if this solar fire system as it stands, with low efficiency steam and relatively expensive collector will work out well.

Funny everyone thinks of different way to do it and there must be an enormous amount of thought put into this problem, but because they rarely record or share their thoughts it does no good. I guess one of the perks of open source comes from documenting the development of the project itself so people can follow the lines of reasoning to see if method x makes as much sense as it seems or not, or if it has not been previously considered and therefore may be worth doing so. As far as I can tell, none of the above has really been considered yet here.