12 research outputs found

    The impacts of electric vehicles and heat pumps load profiles on low voltage distribution networks in Great Britain by 2050

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    The impacts of uptake and electricity load profiles of Electric Vehicles (EVs) and Heat Pumps (HPs) on the low voltage (LV) distribution networks were analyzed. The United Kingdom (UK) has a legally mandated policy concerning reduction of greenhouse gasses (GHGs) emissions. Therefore, the integration of low carbon technologies (LCTs) especially EVs and HPs at the LV networks is expected to increase in the drive to reducing the GHGs emissions. Future uptake scenarios, adapted from the National Grid studies, of EVs and HPs were developed for a real and typical urban LV distribution network in Great Britain (GB). Gridlab-D, an agent-based power system simulation software, was used to model the LV distribution network. The model was run for four different scenarios considering seasonal load profiles and projected EVs and HPs uptakes for each of the year 2020, 2030, 2040 and 2050 respectively. The results were analyzed in terms of transformer loading, voltage profiles of the feeders, and the ampacity loading of the cables for the different scenarios of the years

    Nigerian indigenous hens show more discomfort-related behavior with visual separation than physical separation from their chicks: An exploratory study

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    The Nigerian indigenous hens exhibit their full natural behavior repertoires, including maternal care. The strong maternal bond between the hen and her chicks is established prior to hatching. Maternal care of chickens is essential for both exotic and indigenous chickens. This study compared the behaviors of six hen-chick pairs in a physical (PHY) and visual (VIS) separation test for 10 min. All the six hen-chick pairs were subjected to PHY separation on the 8th day of post-hatch and a VIS separation on the 12th day of post-hatch. The PHY separation involved the use of a wire mesh to separate the hen from her chicks, while the VIS separation involved the use of a trampoline to separate the hen from her chicks. The hen's behavior was recorded during the 10-min separation period. Behaviors recorded included sitting, body shaking, pecking, movements toward the chicks, jumping, pacing, defecation, movements away from the chicks, and preening. We further grouped these nine behaviors into two categories: discomfort-related (pacing, movement toward chicks, body shaking, defecation, and jumping) and comfort-related (sitting, pecking, preening, and movement away from the chicks) behaviors. Before and after each separation, the hens were gently restrained, and a drop of blood was sampled from the wing vein to determine the blood glucose level. Their heart rate and eye temperature were also measured. A two-related samples test (Wilcoxon) was used to compare the behavior of the hens when subjected to the PHY and VIS separation. Eight out of the nine behaviors monitored did not differ between the separation types. However, the frequency of pacing by the hens was greater (z = −2.201, P = 0.028) in the VIS separation than in the PHY separation. Also, discomfort-related behavior was greater (t(5) = −2.717, P = 0.042) during the VIS separation than the PHY separation. Comfort-related behavior did not differ between the separation types. The change in eye temperature, heart rate, and blood glucose was similar in the two separation types. In conclusion, Nigerian indigenous hens displayed more discomfort-related behavior to the VIS separation from their chicks, but this was not associated with physiological responses indicative of stress.Peer Reviewe

    Adaptive thermal model for loading of transformers in low carbon electricity distribution networks

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    The uptake of low carbon technologies, particularly Electric Vehicles (EVs) and Heat-Pumps (HPs), at the low voltage (LV) distribution network, in the quest of cutting down on greenhouse gas (GHG) emissions in the transportation and residential sectors, has the potential to cause general load increase and may lead to higher and longer peak load demand. This development can, as hinted in previous studies, pose a real challenge of capacity overloading to transformers at the LV distribution network of electricity system. Prolonged periods of transformer overloading could lead to premature transformer failure and shortens transformer's life expectancy. A direct solution to addressing transformer overloading is the upgrading of the transformer capacity. However, the number of LV distribution transformers in electricity system to be upgraded and the resources needed for such operation make the solution less desirable to the Distribution Network Operators (DNOs). Therefore, it is important to develop cost-effective solutions for the optimal utilization of the existing transformer capacity. Adaptive thermal loading of transformers is one of such solutions. This paper focusses on the Adaptive Thermal Loading (ATL) of transformers in LV distribution networks with considerable penetration level of EVs and HPs. The thermal model of a 500-kVA, 11/0.415-kV (no load), 50-Hz, Dyn11, ONAN mineral oil filled, free breathing, ground mounted transformer serving a real and typical urban LV network in the United Kingdom (UK) is developed based on IEC 60,076–7:2005 standard and used as the case study. A method of adaptive thermal loading of the transformer is presented to examine its capacity performance when serving the future load of the LV network following the integration of projected uptake figures of EVs and HPs for the years 2020, 2030, 2040 and 2050 into the network. Given the load and temperature forecasts of a day, the method aims at optimizing, considering the real and present conditions of the operating environment, the overall daily transformer capacity utilization that gives maximum daily return on investment without undermining reliability of supply and normal life expectancy of the transformer. Results show improved performances of the transformer when the adaptive thermal loading method is used

    Dispatch model for analysing the impacts of electric vehicles charging patterns on power system scheduling, grid emissions intensity, and emissions abatement costs

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    Dispatching of generating resources at Power Stations is a complex task based on the balance of economics, contractual agreement, regulations, and environmental consciousness in terms of emissions produced in the course of electricity generation. The complexity of the task could be exacerbated with the integration of a large percentage of Electric Vehicles (EVs) in the quest to reduce CO2 emissions in the transportation sector. In this paper, a dispatch model, which is suitable for analysing the impacts of charging patterns of EVs on grid emissions intensity and emissions abatement costs, is described and developed for dispatching generating resources/technologies. The dispatch model is based on the correlation between historical system load and capacity factors of generating units. The dispatch model is tested on data from the UK power system on a typical winter day in December 2015 with an assumed 50% integration of EVs on the system. Results show amongst others that charging of EVs in the off-peak period may affect the optimal deployment of generating technologies/resources with storage capacity and could produce a higher average grid emissions intensity

    Fournier's gangrene and perianal abscess: Is there a common denominator?

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    Fourniers gangrene is a genital catastrophe with significant morbidity and mortality. We present a 57 year old patient with fournier's gangrene and perianal abscess. He had serial debridements with daily bedside dressing and secondary closure of the scrotal defect. Further evaluation during the course of treatment revealed diabetes mellitus. We conclude that aggressive multidisciplinary treatment will improve outcome and that the existence of fournier's gangrene coexisting perianal abscess could alert the clinician to the possibility of underlying diabetes mellitus - A common denominator

    Economic uncertainty of pandemic and international airlines behaviour.

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    This paper examines the role of uncertainty due to infectious diseases in predicting twenty International airline stocks within a nonparametric causality-in-quantiles framework. We observe that: First, the BDS test shows that nonlinearity is very important when examining the causal relationship between EMV-ID and airline stock returns and its volatility. Second, the nonparametric quantiles-based causality test shows that airline stocks predictability driven by pandemic-based uncertainty is stronger mostly around the lower quantiles, with weak evidences in middle and higher quantiles. Relevant policy implications can be drawn from these findings

    Localised energy systems in Nigerian power network

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    Nigerian Power Systems has changed from vertically integrated government-owned electricity network to a largely privately-owned electricity network. Despite this transformation, the utility is still struggling to overcome challenges of providing reliable electricity supply to all its citizens, heavy dependence on fuel and meeting greenhouse gas emission target. The increase in power demand due to growing population and industrialization in the face of depleting fossil fuel resources and low government investment on power generation has stimulated the country's efforts in adopting power generation from renewable energy sources. The use of local energy systems is considered suitable to meet its ever increasing power demand. The local energy systems, defined in this research as medium sized electricity projects (between 5-50MWe) such as solar arrays and wind turbines could bring considerable benefits to local communities in terms of power security, environment friendly and economies. This paper investigates the impact of growing electricity demand on a 33kV distribution network in Nigeria and the benefits of connecting local energy systems to the networks to meet the increasing power demand with regards to network voltage and power losses
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