When people talk about solar cells, they typically think of silicon wafers, produced in a non-trivial process. But do we really need silicon to harvest solar energy? Actually not. Far cheaper alternatives do exist, keyword perovskite:
A perovskite solar cell (PSC) is a type of solar cell which includes a perovskite structured compound, most commonly a hybrid organic-inorganic lead or tin halide-based material, as the light-harvesting active layer. Perovskite materials, such as methylammonium lead halides and all-inorganic cesium lead halide, are cheap to produce and simple to manufacture.
Solar cell efficiencies of devices using these materials have increased from 3.8% in 2009 to 25.2% in 2019 in single-junction architectures, and, in silicon-based tandem cells, to 28.0%, exceeding the maximum efficiency achieved in single-junction silicon solar cells. Perovskite solar cells are therefore currently the fastest-advancing solar technology. With the potential of achieving even higher efficiencies and very low production costs, perovskite solar cells have become commercially attractive.
Meanwhile the EU has discovered perovskite and started a massive development program, where everybody and his mother in Europe joined in, see list at the bottom.
Price erosion potential: from 75 cent for silicon to 10-20 cent per installed Watt for perovskite. Think 300 Watt panels for 45 euro or dollar. If this will materialize, the most expensive aspect of solar will not be the panel but the space it occupies, certainly in over-crowded Europe.
Jumpers onto the EU perovskite bandwagon:
Solliance Solar Research (NL, BE, DE), TNO (NL), including: