Solar power generation is attracting attention as a way to solve energy problems. However, conventional silicon-based solar cells have one particular weakness - their power generation efficiency depends on the weather. This is why the world is now focusing on the development of perovskite solar cells as "next-generation solar cells." Perovskite solar cells can not only generate electricity on cloudy or rainy days, but even under weak indoor light as well, all while being lightweight and easy to make! Now competition to develop these cells for practical use is intensifying around the globe. In this episode, we examine how the innovative technology was created by Japanese researchers, and the incredible potential perovskite solar cells hold for the future.