PhD Thesis - Energy Systems Research Unit - University of Strathclyde

5 Load Following Supply Algorithms
This chapter presents the algorithms used to describe the behaviour of a variety
of load following supplies. In each case, the residual demands, supplies and fuel
availabilities are sent to each model at the matching stage, in the order in which
they were chosen, for each consecutive half-hourly timestep, and this
information is amended appropriately and returned. Each technology also gives
a relevant output graph, showing plant use or storage characteristics, and
information about overall fuel consumption or energy taken in and given out, as
appropriate.
These models have been designed to be generic to a particular plant type group
(e.g. gas turbines or fuel cells), and require only readily available
manufacturers’ data in order to predict performance. The main issues that affect
the performance of a particular type group are considered, and the performance
analysis is based on these. This allows a wide variety of sizes and types of plant
to be considered without having to run extensive tests to find specific data for
each single engine, turbine or fuel cell, which would be time-consuming, much
of the required information may be proprietary, and would quickly be out of
date. This level of performance modelling is appropriate for the initial
suitability assessment through demand and supply matching that is being
considered here.
5.1 Vehicle Performance Algorithm
The input to this part of the procedure, at the demand and supply matching
stage, is a transport demand profile (km/h versus time) and the appropriate fuel
availability profile. From these, the ability to meet the transport demand, and
half hourly fuel use, must be derived. To do this, the specific fuel consumption
of the chosen vehicle, the amount of fuel that can be stored on board, and the
refuelling requirements are defined when choosing the load following supplies,
and examples of the vehicle definition windows for the different fuel types can
be seen in Appendix 1 (Figures A1.40 to A1.44). This information is then used
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