The so-called high-temperature superconductors already exist....

The so-called high-temperature superconductors already exist. They are a relatively recent development. In the old days, some 50 years ago, you had to cool materials to near absolute zero (0 Kelvin or −273.15 °C). They are called high-temperature superconductors compared to the older technology. Until recently, "the superconductor with the highest transition temperature at ambient pressure was the cuprate of mercury, barium, and calcium, at around 133 K (−140 °C). There are other superconductors with higher recorded transition temperatures – for example lanthanum superhydride at 250 K (−23 °C), but these only occur at very high pressures." So we are gradually getting closer to room temperature (even a cool-room temperature would be great!), which is where we want to be. I reckon the time will come, even if the recent discovery proves to be a hoax. I like the recent discovery and the discussion here due to my professional bias, as well as my lead bias (and this is where I will declare a potential conflict of interest: that I am invested in BML ;-)). Also, I like the promotion of the knowledge that climate friendly technologies are not limited to wind and solar - they include energy efficiency, where room-temperature superconductivity would be a major breakthrough!