At Eni's Renewable Energy and Environmental R&D Centre, in conjunction with the Technical Research Center of Finland, Massachusetts Institute of Technology (MIT), National Research Council (CNR) and numerous universities in Italy, we have developed a system that generates electricity from the sun. It uses polymers and other organic components as photoactive materials and has the advantage of being able to use a very thin plastic film that is printable like newsprint. The advantage over current silicon technology is that far lighter and more flexible panels can be built, which can be integrated into different systems and situations at a reduced cost. In addition, compared to traditional solar panels, both the environmental impact and cost of disposal are also lower. By way of comparison, a kilo of crystalline silicon is enough to produce just over 2m2 of solar panels, while the same quantity of organic material used in OPVs is enough to cover an entire football pitch with solar panels.
Solar is one of the most promising renewable energies. Some of its features, however, limit its widespread use. Currently used metal and glass panels with silicon cells require supports strong enough to hold their weight. Furthermore, the modules must be installed facing south and at the correct angle according to the site's latitude. Installation and maintenance of such equipment is costly and requires specialised expertise. Our OPV technology's lightness, flexibility and sturdiness means it can be installed almost anywhere, including on inflatable supports, which can even be launched by parachute. In this way, solar energy could even be taken to inaccessible places without requiring additional infrastructure.
When we began to develop organic photovoltaic, our aim was to create a technology as flexible, light and easy to install as possible, while also being robust and efficient. We thus had to find a system able to convert sunlight into electricity with an efficiency comparable to currently used silicon cells, but thinner and lighter. After several laboratory trials, we concentrated on an optimised sequence of layers, including two electrodes holding the active polymer material, comprising an electric charge donor and acceptor. These layers are literally printed onto a thin plastic film, like with different-coloured inks on a magazine page, using the rotogravure technique. The printed sequence is just a few microns thick, thinner than a red blood cell. Another advantage of our OPV is its high efficiency even in diffused light: a feature that makes it suitable for electricity generation in low light conditions, alongside conventional solar.
Organic photovoltaic – Eni's research | Eni Video Channel
Cost-effective and versatile, OPV technology has great potential for integration into our industrial operations. Installed on buildings and industrial plants, it can help to achieve energy self-sufficiency in operations in remote places. It is ideal for powering sensors and recharging mobile devices where a connection to an electricity grid may not be immediately available. Outside of our industry, we are also focusing on Building-Integrated PhotoVoltaics (BIPV), a new concept in construction where solar cells aren't installed on the building, but built into its structural elements: bricks, roof and floor tiles and other structures, such as noise barriers or any surface exposed to light.
The sustainable lightness of energy - #innovation4energy | Eni Video Channel
Beyond its industrial uses, the most interesting opportunities for our OPV technology concern local development and humanitarian intervention. For example, bringing electricity, albeit low power, to isolated communities without requiring large technical resources in situ. Given its cost-effectiveness and ease of use, in fact, OPV installation and operation does not require any specialist skills. By applying the film to inflatable structures, it would be possible to air-drop small photovoltaic installations into areas not connected to the electricity grid, following incidents or disasters for example: This would make it possible to power lighting, diagnostic systems, and emergency radio or telephones.