Subsistence fishing employs hundreds of millions of people around the world. It’s an enormous business worth trillions of dollars. It’s also a dirty business. High-cost diesel motors and expensive, inefficient lights consume huge amounts of fossil fuels, leaving a considerable carbon footprint. But these lights are essential. Venturing out onto the high seas in a small boat is always dangerous, but night fishing is absolutely treacherous, so although good lighting saves lives, it also requires a lot of power. We follow the female scientists who are developing solar tech to help fisherfolk in South East Asia reduce their impact on the environment, improve their health and put money back in their pockets.