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.

https://solar.lowtechmagazine.com/2021/10/how-to-build-a-low...

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.