Hydroponics advances with clean energy and water reuse **Note:** If the original text contained more content, please provide the rest so it can be translated accordingly.

Urban vegetable production has advanced with solutions that combine productive efficiency and reduction of environmental impacts. According to agronomist Albertina Wieth, an experimental hydroponic system has demonstrated its ability to produce lettuce with a strong reduction in carbon emissions by integrating solar energy and water reuse. The model was evaluated in a recent study that analyzed a hydroponic structure powered by 100% renewable energy and irrigated with treated gray water from sinks, showers, and kitchens. The results indicated a 94% reduction in CO₂ emissions compared to conventional systems, in addition to 2.4 times higher energy efficiency. Productivity was maintained, with lettuce heads reaching 682 grams, with no loss in nutritional quality. The estimated investment for implementation ranged between R$ 2,500 and R$ 3,500, with a projected return between two and three years. The operation occurs in a closed cycle. Solar panels of 100 watts power a 12-volt ...