Fig. 1. Equatorial coordinate system

Fig. 2. Unit vectors of sun and solar panel in horizontal coordinate system

Fig. 3. Schematic of shading distance before and after solar panel

Fig. 4. Schematics of shading distance between non-southern faced buildings. (a) Schematic of non-southern faced buildings; (b) projection angle of sun rays on vertical plane consistent with orientation of building

Fig. 5. Schematic of α_s and αp[26]

Fig. 6. Normal vector of polar axis sun-tracking solar panel in equatorial coordinate system. (a) Projection of normal of tracing solar panel on XOZ coordinate plane; (b) projection of normal of tracing solar plane on XOY coordinate plane

Fig. 7. Normal vector of horizontal axis sun-tracking panel in horizontal coordinate system. (a) N-S horizontal axis sun-tracking panel; (b) E-W horizontal axis sun-tracking panel

Fig. 8. Newly proposed coordinate system and normal vector of INSA tracked solar panels.(a)Relationship between newly proposed coordinate and equatorial coordinate systems; (b)normal vector of INSA tracked solar panels in newly proposed coordinate system

Fig. 9. Scheme of vertical axis sun-tracking system and vector of sun-tracking panel normal in horizontal coordinate system. (a) Scheme of vertical axis sun-tracking system; (b) projection vector of o solar panel normal on horizontal plane

Fig. 10. Sun-tracking efficiency versus time for different sun-tracking techniques. (a) Equinoxes; (b) winter solstice

Fig. 11. Back view of INSA-MP system in direction of INSA

Fig. 12. Tracking efficiency versus time for different tracking systems. (a) Equinoxes; (b) solstices

Fig. 13. Scheme of solar tower and reflection of light. (a) Schematic of solar tower; (b) relationship among vectors i, r and n'_c