PhD Thesis - Energy Systems Research Unit - University of Strathclyde

All of these different possible fuel, intermittent electricity and auxiliary supplies
and storage technologies could be used in a variety of combinations to fully
satisfy the total energy demands for this island, but a technically attractive range
of potential mixes of technologies and processes emerge from the analysis
carried out using MERIT, and are discussed in Section 8.3. The final, most
suitable solution, however, would depend on a variety of other factors, which
might include available land, local geography, positioning of buildings, existing
plant, cost of equipment, available subsidies, and projected future demand.
8.3 Analysis Results
MERIT has been used to study a variety of different demand scenarios, to
ascertain the most technically attractive use of the available local supplies.
When considering seasonal fuel supplies such as biodiesel or ethanol from
energy crops, it is necessary to consider the half-hourly demand and supply
profiles over a whole year. The required plant types and sizes, and the amount
of fuel production and storage necessary to allow all the energy requirements
(for electricity, heat and transportation) to be met are ascertained for these
different possible supply mixes, and the results are discussed below.
8.3.1 Intermittent Electricity Supply
The use of an all-intermittent electrical supply was considered, where all the
electricity was generated via wind turbines, and electrical storage heaters and
electric vehicles were used to meet the heat and transportation demands
respectively. Despite the fact that the storage heaters and vehicles provide some
storage of excess electricity, a substantial amount of other electrical storage
would still be required. In particular, the co-relation between the electricity
supply and the overnight re-charging requirements of the vehicles was not good,
as this created too large a demand overnight. The electrical storage necessary
would be required for periods of one or two months at some times, and would
require rapid switching at other times. This pattern of use and the required scale
of storage make batteries unsuitable due to the equipment costs and losses which
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