The decarbonization of the energy sector to mitigate climate change is a key challenge for the European Union (EU). This mandates a rapid and widespread implementation of a clean and affordable energy infrastructure in which photovoltaics (PV) will be a main pillar. Currently, PV represents only a small fraction of the global energy supply and PV modules are almost exclusively imported from outside the EU, associated with supply risks and a high CO2-footprint. Emerging perovskite PV has a tremendous potential to overcome these issues and revolutionise the EU energy sector. To unfold this potential, the DIAMOND project joins 6 European leading universities (UGroningen, UUppsala, EPFL, URome-TV, UPorto, UMarburg), 2 research institutes (Fraunhofer ISE, CEA) and 4 industry partners (Dyenamo, BeDimensional, Solaronix, PixelVoltaic) from 7 different countries to develop ultra-stable, highly-efficient and low-cost perovskite PV with minimised environmental impact. To achieve stabilities far beyond all previous achievements of PV solar cells, the project targets to develop novel hermetic encapsulation approaches and highly stable device designs that are evaluated by standardized and novel stability assessment methods. DIAMOND also aims to optimise materials and cell stacks to reach efficiencies exceeding the record values of silicon PV. Fully printable module architectures are targeted for rapid industrial up-scaling, allowing for lowest manufacturing costs and local production in the EU. To minimise the ecological impact, specific device designs that enable lowest CO2-footprint, material criticality and toxicity together with enhanced recyclability are targeted. Combining these ambitions, DIAMOND strives to provide a strong impact on the EUs future environmental, economic and societal development, paving the way for an EU-made sustainable energy technology with lowest CO2-footprint that ensures a full integration into the circular economy.