PhD Thesis - Energy Systems Research Unit - University of Strathclyde

supplies, demands, and available fuel will change after each supply type has
been considered. Also, each supply must be considered in turn for each timestep
being evaluated, rather than looking at one supply over the whole time period,
and then the next. This is because remaining fuel is being stored, and this may
be stored and subsequently used by the first supply technology (as shown by the
hatched lines in Figure 4.9). This fuel would not then be available for another
technology, although the storage profile would suggest otherwise. For this
reason, each technology is considered in turn for each timestep. When each load
following supply technology has been considered for a given timestep, any
remaining fuel, for each different fuel type being used, is added to the amount
being produced at the next timestep. This then stores the fuel and makes it
available for the next timestep, and also creates a storage profile of remaining
fuel.
Figure 4.9 Fuel Availability
When load following supplies which require fuel are being used, the amount of
the relevant fuel type available is checked by the algorithm to ensure there is
enough to run the supply at the required rate. If electricity is the required fuel,
the amount of excess electricity for that timestep is used as the available fuel.
When there is insufficient fuel to run the plant at the required rate, the possible
rate is determined by the algorithm, as described for each plant type in Chapter
5, and a warning message is displayed on the matching procedure window.
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