Office for Environmental Programs - Theses
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ItemModelling a renewable and energy positive community in the Gold Coast Hinterland, Queensland( 2017)Australia’s electricity system is fossil fuel reliant and highly centralised, making it vulnerable to shocks. The community of Tamborine Mountain in South East Queensland has experienced the inherent vulnerability of a centralised system through extended outages as a result of weather and maintenance events. This study addresses Tamborine Mountain’s potential transition to a more secure and independent net positive renewable energy system, in two separate but linked studies. The first study models the optimal renewable energy system using Hybrid Optimisation Model for Electric Renewables (HOMER) software. The optimal system is found to be 36MW of solar PV, eight 1.5MW wind turbines, 1MW of biomass and 368kW of hydroelectricity. This system has a levelised cost of electricity (LCOE) of $0.643/kWh. A post-HOMER analysis examined the practical implications, business case, and different operational options for the provision of this renewable energy system to the community. A community energy model is proposed to raise the required capital cost of $79.3M, and develop community resilience, energy security, and affordability. The second study assesses the community’s willingness to pay (WTP) for three renewable energy models through a contingent valuation (CV) survey. The three models are an independent ‘off grid’ household, a community-owned energy cooperative powered by the mix of renewable energy described in the first study, and the purchase of ‘green power’ from a community owned energy company. The mean WTP was found to be $21,560.49 for an energy independent house, $8091.52 for a community energy cooperative, and a 19.75% increase in bills for renewable energy from a community-owned company.
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ItemEffects of experimental flooding on egg survival of Krefft's River Turtle: implications for freshwater turtle conservation( 2012)Anthropogenic changes to river catchments via changes to flow rate and volume can dramatically influence biodiversity. Most of Australia's major rivers are now impounded from the construction of dams and weirs causing the loss and significant alteration to habitat due to modified flow regimes. Such changes can negatively impact biodiversity, particularly specialist species. For example, anthropogenically altered flow regimes expose freshwater turtle to a seasonal inundation events that are assumed to exacerbate egg mortality during the incubation phase. Thus flooding of freshwater turtle eggs has been identified as an additional threatening process that could further impact both listed and non-listed freshwater turtles. Consequently, understanding the degree of mortality imposed on turtle eggs during incubation is a crucial step to ascertaining management implications from altered flow regimes on turtle populations. Here I conducted experiments to specifically identify the effects of 1) duration and 2) timing of inundation on Emydura macquarii krefftii egg hatching success and hatchling phenotypes. This was done in order to measure both direct and potentially indirect mortality costs associated with altered river flow regimes. Four treatments of eggs; control, 30 minutes submersion, one hour submersion and 6 hours submersion were flooded at nine periods during incubation (within the first 24 hours then every week following). Analysis revealed that inundation for any length of time caused a significant increase in egg mortality compared to control eggs. The developmental age at which inundation treatments were applied also had a significant impact on hatching success, with age 0 exhibiting the highest mortality rate and other developmental ages displaying fairly similar but increased mortality relative to controls. These results suggest that E. m. krefftii eggs are very sensitive to even brief episodes of inundation, especially within the first 24 hours of incubation. Moreover, if other turtle species are proven to exhibit similar sensitivities to inundation during egg incubation from altered river flow regimes these results suggests additional and potentially high mortality to all terrestrial nesting freshwater turtles. Ultimately these results support the need to prioritise informed management of anthropogenically altered flow regimes in order to prevent potential loss of an entire guild of vertebrates and their ensuing ecological function