USEFUL CONSTANTS

USEFUL FORMULAS

Week 1 Formula

Speed of light in vacuum

Energy of a photon

Irradiance ∫ ( )

Air mass

Spectral photon flux ( ) ( )

Photon flux ∫ ( )

Constant Symbol Value Units

Speed of light in vacuum c 2.998 108 m/s

Elementary charge q 1.6 10-19 C

Planck’s constant h 6.626 10-34 J s

Boltzmann’s constant k 1.38 10-23 J/K

Vacuum permittivity ε0 8.854 10-12 F/m

Week 2 Formula

Law of mass action

Diffusion current density (electrons)

Diffusion current density (holes)

Drift current density (electrons)

Drift current density (holes)

Diffusion length (electrons) √

Diffusion length (holes) √

Week 3 Formula

J-V curve of an ideal solar cell

[ (

) ]

J-V curve of a non-ideal solar cell

[ ( ( )

) ]

Open-circuit voltage

( )

( )

Fill factor

Efficiency

Short-circuit current ∫ ( ) ( )

Lambert-Beer´s law ( ) ( ) ( )

Snell´s law

Fresnel reflection coefficient, p-polarization

(

)

Fresnel transmission coefficient, p-polarization

Fresnel reflection coefficient, s-polarization

(

)

Fresnel transmission coefficient, s-polarization

Week 4 Formula

Finger’s resistance

Fick’s law

Week 6 Formula

Sensible heat ( )

Latent heat

Fourier’s law

Newton’s law

Energy per area emitted by a black body

Energy per area emitted by a grey body

Heat in a collector

Energy stored in a water tank

Heat loss of a water tank ( )

Heat stored in a phase change material

[ ( ) (

)]

Solar-to-hydrogen efficiency

⋅ 3

Week 7 Formula

Temperature coefficient ( ) ( )STC STC

d XX T X T T

dT

NOCT Model 2

( 20 )

800cell ambient

NOCT CT T G

Wm

Module Ideality Factor ,

exp

PV T

ected

EMIF

E

At MPP I

V V

To the right of MPP I

V V

To the left of MPP I

V V

Battery capacity batt battE C V

C-rate 1

batt

IC rate

Ch

Storage round-trip efficiency 100out

in

E

E

Battery Voltaic efficiency arg

arg

100disch e

V

ch e

V

V

Battery Coulombic efficiency arg

arg

100disch e

C

ch e

Q

Q

Total battery efficiency batt V C

State of charge 100available

batt

ESOC

C V

Depth of discharge arg

100disch ed

batt

EDOD

C V