Oops, I made the kW / kWh mistake myself!
Of course I meant 5 kW * 24 h, or 120 kWh/d as they claim.
Their website suggests a 5 kW system needs 7 banks of tubes, each measuring 4.8 sqm, so 33.6 sqm in total. Brisbane gets an average of 5.25 peak sun hours a day. One peak sun hour is equivalent to 1 kWh per sqm of sunlight. So that 33.6 sqm footprint should collect 33.6 * 5.25 * 1 = 176.4 kWh/day. To achieve the claimed export of electricity alone, the whole cycle efficiency (sunlight energy in to usable energy out) must be 68% - about 2-3 times what the most efficient parabolic trough solar thermal collectors can deliver. That's before you even consider the promised additional benefits of air con and hot water... so let's do that as well. The website distinctly shows a Rotartica absorptive chiller for air con (really only half an AC but let's press on), checking the Rotartica website shows that one unit needs a further 7.2 kW of thermal energy input. If we ran that unit for 8 hours that would then be an additional 57.6 kWh per day... add that to the promised 120 kWh electrical output and you get 177.6 kWh. Hot water? 200 L a day will chew up another 5.8 kWh to heat by 25 degrees (in a perfect heater) so now we're up to 183.4 kWh per day... enough?
Earlier I compared the Thermogen efficiency to the best possible parabolic trough generation efficiency, which is about 25%. These concentrate sunlight into a central column which reaches a high working temperature (400+ degC). Evac tubes have a much lower maximum temperature (stagnation temperature ~ 250 degC but water can't get that hot without boiling, at 10 bar (pressure rating of most mains pressure tanks) it only reaches 180 deg. This is low-temperature stuff and thermal efficiencies for a heat engine decrease with operating temperature. A more realistic full cycle efficiency for this type of application would be 7-10%. Maybe 15% if everything works well but beyond that I think we're in dreamland.
The long and the short of it is:
I think the claims of the Thermogen website are at best hopelessly optimistic, and at worst fraudulent.
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