PERC vs N-Type vs HJT

Which solar cell technology is best?

Three solar cell technologies compared for UK homes: PERC MONO (p-type): Efficiency: 20-22%. Degradation: 0.45-0.55%/yr. Temperature coefficient: -0.35%/°C. Cost: £220-£280/panel. 25yr output (4kW): 85,700 kWh. Status: current mainstream, being replaced. Brands: LONGi Hi-MO 5, JA Solar older models. N-TYPE TOPCON: Efficiency: 22-24%. Degradation: 0.35-0.40%/yr. Temperature coefficient: -0.30%/°C. Cost: £250-£310/panel. 25yr output (4kW): 89,800 kWh. Status: becoming mainstream 2026-2027. Brands: LONGi Hi-MO 7, JA Solar DeepBlue 4.0 N-type, Jinko Tiger Neo. HJT (HETEROJUNCTION): Efficiency: 23-26%. Degradation: 0.25-0.30%/yr. Temperature coefficient: -0.26%/°C. Cost: £300-£400/panel. 25yr output (4kW): 92,400 kWh. Status: premium. Brands: REC Alpha, Meyer Burger, Panasonic. BEST VALUE FOR UK: N-Type TOPCon — 5-10% more output than PERC at only 10-15% higher cost. Best balance of performance and price. HJT is premium — worth it only for very limited roof space. Sources: Manufacturer datasheets, NREL (nrel.gov), Fraunhofer ISE, PV Magazine.