PhD Thesis - Energy Systems Research Unit - University of Strathclyde

it can be deduced that reductions in micro-trigeneration system fuelconsumption due to changes in the supply side (plant modifications) lead toan improved energetic and environmental performance. On the contrary,reductions in micro-trigeneration system fuel consumption due to changes inthe demand side (reduction in thermal demand/operating hours) result in alower system’s energetic and environmental performance.Although from a thermal performance point of view, factors such as fuelconsumption, cycling or system efficiency are not affected by how thecogenerated electricity is used, all three performance criteria are affected.Compared to a similar building and plant system scenario where thecogenerated electricity was used to cover for the building’s own electricaldemand and the surplus exported, exporting all the electricity and importingall the electricity from the grid at the current levels of grid efficiency andemission factor results in a decrease in both primary energy and emissionsavings. On the other hand, if the same principle adopted for the photovoltaicFIT in Malta is adopted in this case as well (FIT is applicable only to theexported electricity) for the selected financial parameters, that is, the Feed inTariff, cost of fuel and the electricity tariff, exporting all the cogeneratedelectricity improves the financial feasibility of the system.For all scenarios, the financial performance of the system increases withincreasing electricity tariffs and decreases with increasing LPG prices. Themagnitude of this increase or decrease is however very dependent on theeconomic parameters selected.In general it was observed that the impact due to changing operatingconditions was highest for the financial performance of the system, showingthat the system’s financial performance is very sensitive to changes in theselected operating conditions (and economic parameters).Finally, although grid network improvements and decarbonisation do not233