Lighting costs

The total annual costs for a lighting installation are composed of capital costs for acquisition and mounting (depreciation and interest) as well as operating costs (energy, lamps and maintenance). Simple and quick installation, good accessibility and simple maintenance of a lighting installation must therefore be considered as early as the luminaire selection and lighting installation design phase.

The total annual costs K for a lighting installation are composed of the following cost components:

  • installation costs,

  • energy costs,

  • lamp costs, and

  • maintenance costs.

They are calculated using the following formula.

In which:

n1

number of all lamps

n2

number of lamps per luminaire

K1

cost of one luminaire

p1

debt service for K1 (interest and depreciation)
in %

K2

costs of installation material and mounting per
luminaire

p2

financing costs for K2 (interest and depreciation) in %

tB

yearly operating time in h

a

costs of electrical energy per kWh, including
pro-rata supply costs
(basic price)

P

power consumption of a lamp including
control gear in kW

tL

useful service life of a lamp in h

K3

price per lamp

K4

costs per lamp replacement

R

cleaning costs per luminaire and year

This basic formula can be used in software applications for economic efficiency comparisons of lighting installations. An example for this is the TRILUX efficiency calculator (see section 1.3.4.4 of this chapter).