Legend has it that at the end of every rainbow is a pot of gold hidden by a leprechaun. In the laboratories of the Renewable Energy and Environmental Research Centre, they have struck gold with luminescent solar concentrators (LSCs), which use certain colours from sunlight to produce elettricity. The warmest of them (red, orange and yellow) they use to make our surroundings more comfortable.

This research yielded the Eni Ray Plus® technology, employed in Domal's Smart Window. Produced from transparent panels made by Arkema (containing suitable dyes from Eni laboratories), the Smart Window can charge a battery that, hidden in the frame, feeds a series of sensors that monitor internal and external temperature. This lets it automatically move the shutters installed in the double-glazing and ensures the surroundings are warm and well lit.

Thanks to Smart Windows, it will be possible to build new buildings whose energy is sustainable, as well as restructure old buildings and make them more efficient. All it takes is to replace the old windows. There is no need to work on the existing walls or electrics. For example, by applying Smart Windows to a 1980s or 1990s building in Milan, you can save 50% on energy and – in houses built in warmer climates – up to 75%.
In new constructions, on the other hand, you can connect the windows electrically, using Eni Ray Plus® technology, and place traditional solar panels on the roof to make the entire surface of the building active. This way, we can go beyond the simple automatic blinds mentioned above and apply our technology even locally, to other appliances in the sector of home automation, like LED lighting, chargers for smartphones and other devices, and sensors.

Another key feature of LSC panels is their yellow colour. Besides concentrating sunlight on photovoltaic panels placed in the frame to produce electricity, the yellow colour allows us to increase light efficiency by spectral conversion to the wavelengths most conducive to the human eye, for visual comfort. But Eni's research does not stop there. At the Eni Renewable Energy and Environmental Research Centre, we are developing red LSC panels, suitable as transparent cover for greenhouses and nurseries, because they do not interfere with plant photosynthesis. But we are also working on new LSCs in other colours for other uses.