A new project funded by the European Commission through the Horizon 2020 Programme aims at developing optical nano-antennas as cost-effective solar energy harvester for a greener future

Most energy sources we use today have low efficiency, rely on non-renewable resources and cause severe damage to our planet by contributing to global warming. GreEnergy envisions the use of the cleanest energy source available: the sun. The sun is the world’s most powerful and abundant energy resource, and offers a nearly unlimited supply of energy to our planet. However, according to the Joint Research Centre (JRC), current solar photovoltaics (PV) produce roughly 4% of the world’s electricity, due to their low efficiency and relatively high costs.

GreEnergy’s ambition is to define a new paradigm in the field of solar energy harvesting, by prototyping a self-powering system based on optical nano-antennas which can harvest solar energy, rectify the AC signal and use it to charge a micro-supercapacitor. The targeted overall efficiency of the demonstrators is around 20-40%, which is competitive with respect to the state of the art. In addition, the maximum theoretical efficiency of GreEnergy’s approach is much above the theoretical limit of a single PV cell efficiency, leaving ample room for further technological improvements.