PhD Thesis - Energy Systems Research Unit - University of Strathclyde

the year, and for different days of the week. An annual profile is then created,
and the magnitude of this profile can also be scaled up or down by applying a
different overall annual consumption figure. This profile may then be added to
the database of profiles for selection for matching. When a profile is chosen
from the database, only the demands for the time period being considered are
extracted. Profiles from the database can be selected in multiples, which
multiplies the magnitude of the profile by a chosen figure. When selecting
multiples, the user can specify a diversity factor, which introduces a degree of
variability between the profiles.
A number of methods for incorporating transport demand have been considered
for this procedure, and it has been decided to define the demand for transport as
a profile of distance that a vehicle or group of vehicles require to travel in a
certain period of time (km/h), against time. Therefore, the profile shows the
number of km that require to be travelled by a vehicle or group of vehicles per
hour throughout each day, just as the electricity demand is the amount of
electricity that is required per hour, and is given in kWh per hour (kW) and,
later, the demand for a liquid fuel is given in litres per hour. This keeps all
demand types equivalent.
Transport demand profiles can be created using the Profile Designer, where the
half-hourly demands may be input, and, if desired, the overall daily transport
demand can be calculated from the number of vehicles and the number of
kilometres per day per vehicle, and applied to the profile. Otherwise, as km/h is
also the measure of speed, by knowing the average speed of a single vehicle, the
distance it requires to travel per hour is known, and multiplying this figure by
the number of vehicles gives the necessary distance per hour. For example, if
two tractors run at an average speed of 10 km/h between set times of the day, the
transport demand is 20 km/h between these set times. This information is then
be used to create a profile of vehicle use throughout the day, varying with time
of year, weekdays and weekends if necessary, to create an annual transport
demand profile. This is illustrated in Figures 4.1 and 4.2, which show the
definition of a daily transport demand profile, and the derived yearly demand,
82