Rant
[The article goes on to say that "solar [is] more expensive than burning coal or oil. That will change if Lonnie Johnson’s invention works..."
That's untrue, of course, as coal- or oil-burning generators also convert heat into electricity, with the same sort of low efficiency as solar-thermal does
]
Wow, so they "convert heat into electricity, with the same sort of low efficiency as solar-thermal does". Must be the same then! Do you understand how they do this? Solar and fuel burning generators are two entirely different beasts, and other than the fact they both produce electricity have no similarities.
There's no point retrofitting fuel burning stations with JTEC. That would be silly. One it's expensive to rip out the turnbines, generators and excitors etc, and secondly steam powered generators need super heated steam for safety reasons* which seems a bit of a waste in a JTEC system.
You could of course bolt JTEC onto the end of the LP stage, harvesting some more of the heat from the spent steam before you shove it through the cooling towers. That's where the massive efficiency losses lie in fuel burning plants so there are gains to be made there. You then have the problem of either matching the JTEC output to your steam generator, or building another national grid interface for it which won't come cheap.
Or, you could build new fuel burning stations specifically designed to drive JTEC generators.
Trouble is you also have the issue with the fact that FOSSIL FUELS ARE EXTREMELY FINITE.
Ergo substantially improving the viability of solar energy is a good thing and we should be very happy.
In the efficiency maths you should also remember that fuel burning generators are a bitch to get up to speed from cold, so unless you intend to take a generator off line for maintenance etc you need to keep them running (not at full bore mind) so they still use fuel even when the grid says "no ta, we're just taking the nukes power at the mo". Who cares if we're using up some extra sun light compared to coal? There's a few billion years more of that to come - you reckon coal's gonna last another 50?
* condensed water in a steam turbine is very, very bad news. The water droplets are like bullets and strip turbine blades like a farmer strips ears of corn. Then you have 2 issues - firstly white hot, razor sharp turbine blades flying out at random angles and great speed, and secondly, an unstable turbine weighing ~500 tonnes rotating at 3000 RPM. They balance them carefully for a reason you know.