Table 3:

Mean absolute percentage errors (%) in the visible range due to tilt of the plaque and due to combined effects (BRDF, shadow and tilt) for clear skies and for overcast condition. Statistics calculated from level surface (0° tilt) to maximum zenith tilt angle as indicated on the table, including all azimuths. Smallest errors for each sky condition and plaque are formatted in bold. Numbers in parenthesis are the standard deviations. Statistics calculated over all simulations included in each evaluation and over all visible wavelengths.

θv = 0°
Conversion	Max. Tilt	Tilt		Total, White PTFE		Total, Grey PTFE
		Clear*	OC	Clear*	OC	Clear*	OC
BRDF (Eq. 6)	3°	1.4(±2.1)	0.0(±0.0)	2.2(±2.2)	11.1(±0.2)	1.5 (±2.0)	0.8 (±0.2)
	6°	2.8(±3.7)	0.1(±0.1)	3.7(±4.1)	11.2(±0.4)	2.7 (±3.5)	0.8 (±0.4)
	9°	4.2(±5.3)	0.3(±0.3)	5.3(±5.9)	11.3(±0.6)	4.0 (±5.1)	0.8 (±0.5)
	12°	5.7(±6.8)	0.5(±0.5)	6.9(±7.6)	11.5(±0.9)	5.3 (±6.6)	0.9 (±0.6)
Lambertian (Eq. 7)	3°	1.4(±2.1)	0.0(±0.0)	3.4(±2.3)	4.7(±0.2)	4.8(±2.4)	7.2(±0.2)
	6°	2.8(±3.7)	0.1(±0.1)	4.6(±3.9)	4.8(±0.4)	5.6(±3.4)	7.1(±0.4)
	9°	4.2(±5.3)	0.3(±0.3)	6.0(±5.6)	4.9(±0.6)	6.6(±4.8)	7.1(±0.6)
	12°	5.7(±6.8)	0.5(±0.5)	7.4(±7.3)	5.1(±0.9)	7.7(±6.3)	7.1(±0.7)
θv = 40°
Conversion	Max. Tilt	Tilt		Total, White PTFE		Total, Grey PTFE
		Clear*	OC	Clear*	OC	Clear*	OC
BRDF (Eq. 6)	3°	1.4(±2.1)	0.0(±0.0)	1.8 (±2.3)	4.4(±0.2)	2.3(±1.9)	20.8(±1.6)
	6°	2.8(±3.7)	0.1(±0.1)	3.4 (±4.1)	4.5(±0.3)	3.5(±3.3)	20.8(±2.9)
	9°	4.2(±5.3)	0.3(±0.3)	5.0 (±5.8)	4.7(±0.5)	4.7(±4.7)	20.8(±4.2)
	12°	5.7(±6.8)	0.5(±0.5)	6.5 (±7.5)	4.9(±0.7)	6.0(±6.2)	20.7(±5.5)
Lambertian (Eq. 7)	3°	1.4(±2.1)	0.0(±0.0)	2.3(±2.2)	2.0 (±0.2)	10.3(±5.9)	6.0(±1.2)
	6°	2.8(±3.7)	0.1(±0.1)	3.7(±3.9)	2.1 (±0.3)	11.0(±5.9)	6.0(±2.3)
	9°	4.2(±5.3)	0.3(±0.3)	5.2(±5.6)	2.2 (±0.5)	11.8(±6.3)	6.1(±3.1)
	12°	5.7(±6.8)	0.5(±0.5)	6.7(±7.3)	2.5 (±0.7)	12.7(±7.0)	6.4(±3.8)

^*Clear skies for 20° ≤ θ_s ≤ 60°