Towards commercialisation with lightweight, flexible perovskite solar cells for residential photovoltaics

Metal-halide perovskites have emerged as a promising class of next-generation solar cells. Here, we assess what lifetimes and efficiencies perovskite solar cells (PSCs) have to reach to lower the price of commercial residential photovoltaic (PV) further. We find that using light and flexible substrates, as opposed to heavy and rigid ones, reduces the total installed system cost of PSCs. The flexibility and lighter weight culminate in a lower balance of systems (BOS) cost, as it is possible to use different mounting methods. Concretely, we analyse the scenario when the modules are directly stuck onto a roof without requiring a racking. That reduces both labour and material costs. This effectively lowers the necessary efficiency or lifetime of PSCs (T80 value) required to achieve the same electricity cost as commercialised silicon. For 2021, we find that a rigid perovskite module with 17% efficiency would need at least 24 years to be competitive with residential-installed silicon. In comparison, a light, flexible module with the same efficiency would only need to last 19 years. In 2030, with projected BOS costs, a 23% efficient perovskite module would need to last 24 years if rigid but only 17 years if flexible. Finally, we extended our analysis towards tandem structures with silicon or perovskite-junction. We find that flexible PSCs present a most promising commercialisation route because they can enable low manufacturing and BOS deployment costs, which opens up commercial viability at lower efficiencies or lifetimes.