Fun tidbit, which I didn’t mention in the piece: Drebbel proposed creating some kind of solar-powered central heating system for London in the 1610s. We don’t have many details, other than the fact he thought it would cost £20,000 and would involve heating some kind of very heat-conductive material on top of a hill nearby. Historians assume it would have then involved heating water to be run in pipes to London’s houses.
That's amazing! I suppose that because Fahrenheit wouldn't invent the mercury thermometer until 01714, energy wouldn't be discovered until Emilie du Chatelet's work in 01749, and the heat equation wouldn't be discovered until 01822, Drebbel might have had a hard time in the 01610s calculating how much sunlight and how much heat transfer medium would be needed. But Drebbel consistently did things that should have been impossible in the 17th century (homeostasis with negative feedback, submarines with oxygen generators, high-explosive weapons, and androids, as well as the atmosphere-powered orrery you profiled here), so maybe he had some way.
You could probably make something like this a lot more efficient with TCES, eliminating the losses from conduction in the pipes between the power plant and the houses, but that's pretty hard to do with copper pipes. Maybe salt-fired ceramic pipes would work for TCES transfer. But even sensible heat transfer with a copper heat exchanger would probably have worked fine.
It's an interesting speculation, but it might not be correct. In particular, the subhead about how it might have been highly efficient is crucial to its potential usefulness, but the highest efficiency number claimed is 5%, less than a quarter of current mainstream PV, and an eighth the efficiency of current lab PV. And the "thermo" part seems like it was a red herring.
How efficient is such a device? If Cove's device was 20% efficient it was an unheralded breakthrough, though a toxic one, unlike modern silicon solar panels (contrary to a false statement in the article), and made with relatively expensive materials (antimony isn't just poisonous, it also costs US$11/kg). If it was 2% efficient, it might have been viable in a few niche uses. If it was 0.2% or 0.02% efficient, it was a laboratory curiosity. The article says Cove's prototypes were 2.75% efficient and 5% efficient, producing 45 watts from 1.5m² and 60 watts from 1.125m² respectively, which I calculate as 3% and 5.3% efficient, respectively. But it also says the guy went to jail for a year for defrauding his investors.
But apparently nobody has been able to reproduce Cove's results in the last century.
If you do want to, as the article says, "build low-tech photovoltaic devices, which convert sunlight into electricity", you can get about 1% efficiency out of red copper oxide, another toxic semiconductor like the zinc antimonide intermetallic erroneously described as an alloy in the article; this is a common science fair project for kids, and Wilhelm Hallwachs demonstrated solar panels using this chemistry in 01904, the same year as Cove's first experiments. Toshiba managed to get thin-film red copper oxide PV panels past 8% efficiency last year.
I'm always a bit split when I see it. Even when used genuinely it still comes off as making the comment feel like it exists to showcase long now instead of the response. On the bright side out of all the things to get over this ranks on the "easy" side of the list.
But 01615! We've had working solar power machinery for four centuries.