The European Union's REPowerEU plan targets 600 GW of installed solar photovoltaic capacity by 2030, requiring an unprecedented acceleration in deployment across diverse climatic, regulatory, and grid-integration contexts. The long-term techno-economic performance of photovoltaic installations — encompassing annual energy yield, performance ratio, degradation rate, and levelised cost of energy — varies substantially across panel technologies, mounting configurations, and geographic locations in ways that are not fully captured by short-term laboratory measurements or manufacturer specifications. This study presents a five-year field performance assessment of 84 photovoltaic installations across Germany, Spain, and Sweden, covering three panel technologies — monocrystalline silicon (mono-Si), polycrystalline silicon (poly-Si), and cadmium telluride thin-film (CdTe) — and three mounting configurations — fixed tilt, single-axis tracking, and dual-axis tracking.Mono-Si fixed-tilt systems demonstrated the highest mean performance ratio (PR=0.84 at installation, declining to 0.80 at sixty months), while CdTe thin-film showed the lowest degradation rate (0.3% per year vs. 0.5% for mono-Si and 0.5% for poly-Si). Single-axis tracking increased annual energy yield by 18.4–22.6% over fixed tilt across all technologies. LCOE for the best-performing configuration (single-axis mono-Si) reached EUR 34.2/MWh at the German sites under current financing conditions — competitive with all conventional generation sources and enabling direct grid parity across all study locations without subsidy