This document contains a list of useful constants in physics and formulas related to solar energy and photovoltaics. It includes the speed of light, elementary charge, Planck's constant, Boltzmann's constant, and vacuum permittivity. Formulas cover topics like the speed of light, photon energy, irradiance, air mass, diffusion currents, drift currents, diffusion length, solar cell I-V curves, Lambert-Beer's law, Snell's law, and Fresnel equations. Additional formulas address sensible and latent heat, Fourier's law, Newton's law of cooling, heat storage, temperature coefficients, NOCT model, module ideality factor, battery parameters, and state of charge.

1. USEFUL CONSTANTS
Constant
Speed of light in vacuum
Elementary charge
Planck’s constant
Boltzmann’s constant
Vacuum permittivity
Symbol
c
q
h
k
ε0
Value
2.998 108
1.6 10-19
6.626 10-34
1.38 10-23
8.854 10-12
USEFUL FORMULAS
Week 1
Speed of light in vacuum
Energy of a photon
Irradiance
Formula
∫
( )
Air mass
Spectral photon flux
Photon flux
( )
∫
( )
( )
Units
m/s
C
Js
J/K
F/m

2. Week 2
Law of mass action
Diffusion current density
(electrons)
Diffusion current density
(holes)
Drift current density
(electrons)
Drift current density (holes)
Diffusion length (electrons)
Formula
Diffusion length (holes)
√
√
Week 3
J-V curve of an ideal
solar cell
Formula
[
J-V curve of a non-ideal
solar cell
)
(
(
(
)
)
)
[
Open-circuit voltage
(
(
Fill factor
Efficiency
Lambert-Beer´s law
Snell´s law
( )
∫
Short-circuit current
(
)
( )
( )
( )
]
]
)

3. Fresnel reflection
coefficient, ppolarization
Fresnel transmission
coefficient, ppolarization
Fresnel reflection
coefficient, spolarization
Fresnel transmission
coefficient, spolarization
(
(
Week 4
Finger’s resistance
Fick’s law
)
)
Formula

4. Week 6
Sensible heat
Formula
(
)
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
)]

5. Week 7
Temperature coefficient
Formula
X (T )  X ST C 
dX
(T TST C )
dT
( NOCT  20C )
800 W 2
m
Tcell  Tambient  G 
NOCT Model
Module Ideality Factor
MIF 
EPV ,T
Eexp ected
At MPP
 
I

 V
V
To the right of MPP
 
I

 V
V
To the left of MPP
 
I
 
 V
V
Battery capacity
C-rate
Storage round-trip efficiency
Ebatt  CbattV
C  rate 

I
Cbatt
Eout
100
Ein
Battery Voltaic efficiency
V 
Vdisch arg e
Battery Coulombic efficiency
C 
Qdisch arg e
Total battery efficiency
State of charge
Depth of discharge
1h
Vch arg e
Qch arg e
100
100
batt  VC
SOC 
DOD 
Eavailable
100
CbattV
Edisch arg ed
CbattV
100