Study of the space factor for spectrum-sensitive MJ solar cell arrays

This is the first study of the influence of the annual power generation of PV array considering the optimum space factor. Supposing DNI (direct normal irradiance) spectrum is calculated by the most recent reduced aerosol optical density model, and 3J concentrator solar cell is completely matched to air mass 1.5 calculated from that reduced-AOD or other models, the power loss factor in arbitrary months and hour angle would be calculated. The model was proved by actual observation of PV output under both concentration and non-concentration operation. It was thought that the optimum space factor in 3J concentrator solar cell was more packed than single junction cells such as crystalline silicon solar cells. It was also thought that the area efficiency in 3J solar cells was greater than the single junction cells. These were because that shadow loss in 3J solar cells appeared in low Sun height was relatively less impact to the annual power generation.