Hydro Tasmania, known for most of its history as The Hydro, is the government owned enterprise which is the predominant electricity generator in the state of Tasmania, Australia. The HEC was originally oriented towards hydro-electricity, due to Tasmania's dramatic topography and relatively high rainfall in the central and western parts of the state.Today Hydro Tasmania operates 30 hydro-electric and two gas power stations as well as three wind farms. Wikipedia.
Negnevitsky M.,University of Tasmania |
Nguyen D.H.,University of Tasmania |
Piekutowski M.,Hydro Tasmania
IEEE Transactions on Power Systems | Year: 2015
Integration of wind power generation (WPG) is increasing rapidly worldwide. The variability and uncertainty of wind energy may lead to significant load-generation imbalances resulting in large frequency deviations, hence increasing system operational risks, especially in small and isolated power systems with low inertia and limited capabilities of providing frequency responses. This raises the need for investigating alternatives to current power system operation planning approaches to cope with the uncertain nature of the intermittent generation. This paper presents a risk assessment approach to analyze power system security for operation planning under high penetration of wind power generation. The proposed approach deals with not only steady-state voltage and overload evaluations, but also frequency response adequacy. For fast identification of operational limit violations in the proposed risk assessment method, we develop an analytical procedure for approximating frequency response and assessing the consequences of limit violations without performing dynamic simulations. As a result, the frequency response adequacy assessment can be run simultaneously with the steady-state voltage and overload evaluations. The proposed risk assessment approach is illustrated via its application to a model of a power system with high wind power penetration. © 1969-2012 IEEE.
Morrison A.E.,Monash University |
Siems S.T.,Monash University |
Manton M.J.,Monash University |
Nazarov A.,Hydro Tasmania
Monthly Weather Review | Year: 2010
The cloud structure associated with two frontal passages over the Southern Ocean and Tasmania is investigated. The first event, during August 2006, is characterized by large quantities of supercooled liquid water and little ice. The second case, during October 2007, is more mixed phase. The Weather Research and Forecasting model (WRFV2.2.1) is evaluated using remote sensed and in situ observations within the post frontal air mass. The Thompson microphysics module is used to describe in-cloud processes, where ice is initiated using the Cooper parameterization at temperatures lower than 288C or at ice supersaturations greater than 8%. The evaluated cases are then used to numerically investigate the prevalence of supercooled and mixed-phase clouds over Tasmania and the ocean to the west. The simulations produce marine stratocumulus-like clouds with maximum heights of between 3 and 5 km. These are capped by weak temperature and strong moisture inversions. When the inversion is at temperatures warmer than 2108C, WRF produces widespread supercooled cloud fields with little glaciation. This is consistent with the limited in situ observations.When the inversion is at higher altitudes, allowing cooler cloud tops, glaciated (and to a lesser extentmixed phase) clouds are more common. The simulations are further explored to evaluate any orographic signature within the cloud structure over Tasmania. No consistent signature is found between the two cases. © 2010 American Meteorological Society.
Hull C.L.,Hydro Tasmania |
Muir S.C.,Symbolix Pty Ltd.
Wildlife Society Bulletin | Year: 2013
Understanding the interaction between eagles and wind farms is essential for the development of strategies to minimize collision risk, and to quantify avoidance rates for collision risk modeling. The purpose of our study was to measure the avoidance rates of Tasmanian wedge-tailed eagles (Aquila audax fleayi) and white-bellied sea-eagles (Haliaeetus leucogaster) using a new method, and to examine factors affecting these rates. We conducted eagle surveys at the Musselroe Wind Farm (undeveloped and used as a control); Studland Bay Wind Farm during commissioning and operational stages; and Bluff Point Wind Farm during the operational stage, all in northern Tasmania, Australia. Observers documented flight tracks and behavior of eagles over 875 days during the period 2006-2008. Both species demonstrated a distinct avoidance of the turbines, preferring to fly midway between them. Avoidance rates were 81%-97%, and differed significantly between species and sites, with white-bellied sea-eagles avoiding at a higher rate than wedge-tailed eagles. Eagles at Bluff Point had a higher avoidance rate than those at Studland Bay, even though the sites were only 3 km apart. Both species altered their avoidance rates in response to stages in the wind-farm development, but only the wedge-tailed eagle altered its rate in response to weather conditions, demonstrating a higher avoidance rate during wet and windy conditions. Our study found that the interaction of eagles and wind turbines is complex, which highlights the need for further study of avoidance rates in species at different sites. © 2013 The Wildlife Society.
Haritashya U.K.,University of Dayton |
Kumar A.,Panjab University |
Singh P.,Hydro Tasmania
Geomorphology | Year: 2010
Proglacial meltwater streams draining out of the Himalayan glaciers carry considerable amounts of suspended sediment, with a variety of particle sizes, because of the supraglacial, englacial, and subglacial debris, as well as formation of sediments from erosion by the movement of the ice. This paper examines particle size transported in the proglacial meltwater stream of Gangotri Glacier for seven consecutive melt seasons (May-October, 2000-2006) in order to provide information on (i) temporal variations in the particle size distribution, (ii) texture and mineralogy of the sediments, and (iii) origin and evacuation pattern of the sediments. Our results indicate dominance of silt size (0.002-0.06. mm) particles (71%) followed by sand size (0.06-0.6. mm) particles (24%) and clay size (<0.002. mm) particles (5%) during the melt season, with increased variation as melt season progresses. The sediment contains quartz, feldspar, mica, illite, and kaolinite minerals, which represent a poor to poorly sorted fraction with a coarse to fine skewed textural distribution. Overall, this study indicates a subglacial evacuation pattern of the suspended sediment based on (i) size classification, (ii) higher percentage of coarser particles toward the end of the melting season, (iii) symmetrical to positively skewed with a kurtosis of mesokurtic to platykurtic texture, and (iv) a less-rounded shape of particle size. Our result on the evolution of meltwater pathways indicates a progressively better interconnected drainage system with advancing melt season. The evolution of meltwater pathways also demonstrates complex behavior of the glacial system and the need for a better understanding of sediment availability and contribution. © 2010 Elsevier B.V.
Hull C.L.,Hydro Tasmania |
Cawthen L.,University of Tasmania
New Zealand Journal of Zoology | Year: 2013
Bat carcasses from two wind farms in Tasmania (2002-2010) were assessed to determine the species, sex, age, reproductive state, morphometries, presence of food in the gastrointestinal tract, and evidence of spatial and seasonal patterns. Thirty-eight of the 54 carcasses were Gould's wattled bats, with another 14 likely to be, and two Vespadelus sp. All but two were adults, with an equal ratio of females and males. None were actively breeding when found, and five of the six bats tested, had not been recently feeding. Mortalities predominantly occurred in autumn, with a small difference between sites. There was no pattern in the location of carcasses. There appear to be particular ecological, morphological and behavioural characteristics associated with bat collision risk-tree roosting bats with high wing aspect ratios that forage in the open air at high altitude appear to be susceptible. Seasonal patterns may be associated with specific behaviours. © 2013 The Royal Society of New Zealand.