This report is the product of the completion of the two
year master programme in Master of Science, with concentration
in Indoor Environmental and Energy Engineering,
at Aalborg University, Department of Civil Engineering.

Buildings accounts for about 40 % of the energy usage
in the word today, and artificial lighting stands for
about 15-30 % of the total electricity usage in buildings
in Scandinavia. This shows that there is potential for
reducing the electricity usage of buildings with more
efficient artificial lighting. Prior to obtaining more efficient
artificial lighting, the electricity usage for artificial lighting
should be accurately determined.

The existing estimation methodology for calculating the
electricity usage of daylight and occupancy controlled
artificial lighting in Norway is based on a very rough
estimate. The objective of this thesis is to develop a new
estimation methodology which is both rapid and accurate.
In order to obtain the estimation methodology of daylight
and occupancy controlled artificial lighting, occupancy
profiles and the interior illuminance due to external sky
conditions must be established. The occupancy profiles
were retrieved from gathered data of the occupant time in
an office building. The interior illuminance was determined
with measurements and simulation. The exterior sky
conditions were established with pictures, solar irradiance
measurements and simulation.

Two estimation methodologies are established; the CIE Sky
Method and the Hourly Average Method. The calculated
electricity usage by the methodologies were validated
with measurements of the electricity usage. The Hourly
Average Method proved to be the most rapid and accurate
methodology.