https://techxplore.com/news/2019-10-all-perovskite-tandem-solar-cells-efficiency.html Perovskite solar cells are not new, but it has required decades to get their performance up to snuff, and this one is a milestone in performance that makes them extremely competitive. A silicon solar cell today with similar performance costs around a hundred dollars, while these are made using dirt cheap materials that are easily processed. Silicon is plentiful and they've found ways to make processing it cheaper, but its basically a giant crystal they make out of sand, similar to making glass, and will never be super cheap to manufacture or lightweight. If they can even cut the price in half that's an enormous savings, and they should be able to make them even cheaper over the long run. Combined with the newest battery technology coming on the market over the next year or so this will make it super cheap for even people in the third world to run their entire household off solar power. In places like the US, we may see virtually every rooftop covered with them in about ten years. They are extremely lightweight and, ideally, you could even paint them on a house and they would self-assemble. Self-assembling paint may sound like a futuristic idea, but is already commonplace. There's even a self-assembling paint you can buy that creates micropores that absorb kitchen cooking odors. If your paint gets old and less efficient, you put another coat on. These days, they are even making batteries out of iron oxides, or rust, but those tend to be somewhat big and heavy. Its a whole new world and with AI programs they are already searching through every imaginable cheap material you can think of for possible solutions. Oil is just pumped out of the ground, but you still have to drill for it and process it, and solar will inevitably beat it into the dust for cost. Of course, solar isn't the solution for people in colder climates, but is a perfectly good solution for the majority of people.
