Jellyfish on the Arno

Hydroponic greenhouse for Expo 2015

Brenda Dionisi
April 30, 2015

Watch out, Florentines: there’s a jellyfish on the banks of the Arno near the San Niccolò bridge. But this sea creature won’t sting. It’s the Jellyfish Barge—a ‘floating, self-sufficient cultivation module,’ according to its creators at Florence-based startup PNAT—and its mission is to educate residents and visitors about a sustainable solution to some of today’s most pressing issues in agriculture, including the effects of climate change on the food chain, and the benefits of sustainable agricultural methods that better respect the environment.


The World Bank predicts that by 2050, the world’s human population will reach almost 10 billion. That 40 percent increase will double global food demand. Among the main obstacles to meeting this exponential increment in demand are availability of clean water and arable land. Today, traditional agriculture consumes 70 percent of the world’s fresh water and land; clean water resources are being negatively affected by climate change; and rising sea levels are eating away at arable, fertile lands in coastal areas.

The Jellyfish Barge represents one solution—hydroponic agriculture—to the problem of increasing food demand and decreasing resources for providing it. The hydroponic cultivation method uses 70 percent less water than traditional cultivation methods do, and without the use of soil; instead, it continuously ‘re-waters’ plants with clean, recycled water.

Made of recycled and recyclable materials, the barge houses a solar-powered glass greenhouse in which vegetables are grown hydroponically. The greenhouse sits on a 70-square-metre octagonal wooden base floated by 96 recycled plastic drums and runs on a self-generating renewable-energy system that includes, along with solar power, small wind turbines. The solar panels harvest the energy that transforms up to 150 liters per day of salty, dirty and even polluted water into clean water. Each Jellyfish Barge produces enough fresh food for two families, and modules can be linked for greater efficiencies of production. A barge is easy to build and cost-effective to operate, making it perfect for the world’s poorer areas, where the problems of scarce arable land and clean water and growing populations can be the most acute.

An example of a more local, ethical and sustainable way to provide food without exploiting existing resources and arable lands, the Jellyfish Barge project ties in perfectly with the central theme of the Universal Fair, Expo 2015, ‘Feeding the Planet: Energy for Life,’ opening in Milan on May 1, PromoFirenze spokesperson Mario Curia told The Florentine.

The Jellyfish project, an idea of University of Florence professor Stefano Mancuso, was prototyped by PNAT, a university spin-off co-financed by the Ente Cassa di Risparmio and the Tuscan Region. Involving a team of Florence-based botanists and architects and the support of several local institutions, it was recently named one of five finalists for the United Nations’ UNECE Ideas for Change Award—an international recognition that is, Curia notes, ‘a source of pride for Florence and for the many local actors involved in its realization.’

The Jellyfish Barge will be on display along the Arno until September 2015. Information about the award-winning project is available both on-site and in the Palazzo Vecchio, as well as at

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