Engineering Commons^™

The Need For Energy Storage On Renewable Energy Generator Outputs To Lessen The Geeth Effect, I.E. Short-Term Variations Mainly Associated With Wind Turbine Active Power Output, Tony Kealy

Articles

Many studies investigating the short-term variations associated with the power output from wind turbine generators utilise simulated or modelled data in the analysis. This current study uses short-term empirical data downloaded directly from operational wind turbines via electrical power quality meters. The empirical data shows that the short-term variations (one-second or sub-one-second timeframe) occur continuously over most of the power output range. A novel name is proposed, the Geeth Effect, for this variability phenomenon. The Geeth Effect is measured using the coefficient of variation mathematical expression and is likely contributing to (i) lower-than-expected financial and environmental benefits associated with …

Survey Of Routing Techniques-Based Optimization Of Energy Consumption In Sd-Dcn, Mohammed Nsaif, Gergely Kovásznai, Ali Malik, Ruairí De Fréin

Articles

The increasing power consumption of Data Center Networks (DCN) is becoming a major concern for network operators. The object of this paper is to provide a survey of state-of-the-art methods for reducing energy consumption via (1) enhanced scheduling and (2) enhanced aggregation of traffic flows using Software-Defined Networks (SDN), focusing on the advantages and disadvantages of these approaches. We tackle a gap in the literature for a review of SDN-based energy saving techniques and discuss the limitations of multi-controller solutions in terms of constraints on their performance. The main finding of this survey paper is that the two classes of …

Optimization Based On Movable Damped Wave Algorithm For Design Of Photovoltaic/ Wind/ Diesel/ Biomass/ Battery Hybrid Energy Systems, Mohammed Kharrich, Salah Kamel, Mamdouh Abdel-Akher, Ahmad Eid, Hossam Zawbaa, Jonghoon Kim

Articles

The actual energetic situation has several challenges such as pollution, the rarefaction of fossil fuel and the dangers of nuclear. Renewable sources are proposed as a solution and suggested, such as a cost-effectiveness system. The paper deals with the problem of feeding a domestic load with electricity which should respect the ecologies factors, so this work is a design problem of the hybrid renewable energy systems; PV/biomass, PV/diesel/battery, PV/wind/diesel/battery, and wind/diesel/battery to choose the best one of them which feed the load with the lowest cost. The study’s goal is to design a microgrid system by the minimization of the …

Hosting A Community-Based Local Electricity Market In A Residential Network, Aziz Saif, Shafi K. Khadem, Michael Conlon, Brian Norton

Articles

This paper presents the potential of building a local electricity market (LEM) to boost the deployment of the local energy communities, centred around active customers with distributed energy resources (DERs). To conduct a comprehensive and detailed study on different cases with reduced computational burdens, this paper adopts a simplified modelling approach where the market and network model simulations are performed in a cascaded, decoupled fashion. This allows achieving the optimal LEM output for the energy community with different DER assets that are not bounded by the network constraints. The investigation involves quantifying the benefits brought by LEM to energy communities …

Hosting A Community-Based Local Electricity Market In A Residential Network, Aziz Saif, Shafi K. Khadem, Michael Conlon, Brian Norton

Articles

This paper presents the potential of building a local electricity market (LEM) to boost the deployment of the local energy communities, centred around active customers with distributed energy resources (DERs). To conduct a comprehensive and detailed study on different cases with reduced computational burdens, this paper adopts a simplified modelling approach where the market and network model simulations are performed in a cascaded, decoupled fashion. This allows achieving the optimal LEM output for the energy community with different DER assets that are not bounded by the network constraints. The investigation involves quantifying the benefits brought by LEM to energy communities …

Carbon-Based Interlayers In Perovskite Solar Cells, Aleksandr P. Litvin, Xiaoyu Zhang, Kevin Berwick, Anatoly V. Fedorov, Weitao Zheng, Alexander V. Baranov

Articles

Perovskites are solution-processed, high-performance semiconductors of interest in low-cost photovoltaics. The interfaces between the perovskite photoactive layers and the top and bottom contacts are crucial for efficient charge transport and minimizing trapping. Control of the collection of charge carriers at these interfaces is decisive to device performance. Here, we review recent progress in the realization of efficient perovskite solar cells using cheap, easily processed, stable, carbon-based interlayers. Interface materials including graphene, carbon nanotubes, fullerenes, graphene quantum dots and carbon dots are introduced and their influence on device performance is discussed.

Optimal Sizing Of Energy Storage With Embedded Wind Power Generation, Nicholas Roche, Jane Courtney

Articles

Energy storage technologies are key to increased penetration of renewable energies on the distribution system. Not only do they increase availability of energy, but they contribute to the overall reliability of the system. However, the cost of large-scale storage systems can often be prohibitive, and storage needs to be sized appropriately, both to fill the energy gaps inevitable in renewable energies such as wind and to minimize costs. In this work, a Monte Carlo Simulation is performed to optimally size an energy storage system while minimizing overall system cost. 30 years of historical wind speed data are used to model …

Application Of Demand Response To Improve Voltage Regulation With High Dg Penetration, Chittesh Veni Chandran, Malabika Bassu, Keith Sunderland, Shivananda Pukhrem, João Catalão

Articles

The ability of a consumer friendly demand response based voltage control (DR-VC) program to improve the voltage regulation in a low voltage distribution network (LVDN) with high penetration of DG is investigated. The use of active and reactive power management to regulate the nodal voltage in a distribution network with simple incremental reduction algorithm, in conjunction with DR, is proposed as a solution for over voltage and undervoltage issues in the LVDN. The algorithm micromanages the load and generation in the network enabling the operator to utilize grid resources economically and efficiently while maintaining fairness between consumers with minimum inconvenience. …

Optimization Of Pv Powered Spd Switchable Glazing To Minimise Probability Of Loss Of Power Supply, Aritra Ghosh, Brian Norton

Articles

Suspended particle device (SPD) glazing is an electrically actuated switchable glazing. It requires alternate current (AC) power supply to switch from opaque to transparent state. To power this glazing using PV device requires inverter. Optimization of AC powered switchable SPD glazing using photovoltaic (PV) device has been evaluated using loss of power supply probability (LPSP). Electrically switchable direct current (DC) powered electrochromic glazing was also considered in this investigation as it doesn't need any inverter to couple with PV. It is concluded that behaviour of these glazings is the dominant factor in performance optimization outweighting than azimuthal orientation and inclination …

Performance Of A Campus Photovoltaic Electric Vehicle Charging Station In A Temperate Climate, Ayda Esfandyari, Brian Norton, Michael Conlon, Sarah J. Mccormack

Articles

A photovoltaic (PV) array can be combined with battery energy storage to satisfy the electrical demand of lightweight electric vehicles. Measured solar resource and vehicle energy consumption, together with locational, mechanical and electrical constraints were used to design a vehicle charging station comprised of a 63 m2 10.5 kW AC PV array, with a 9.6 kWh lithium-ion battery. PV output, battery charge and discharge, electricity flows were monitored over one year. Deviations between measured and calculated annual AC generation averaged to 14%. Average annual direct consumption, self-consumption and system self-sufficiency were 8.47%, 30.3% and 74.36% respectively.

A Review Of Co2 Emission Reductions Due To Wind Turbines Using Energy Benchmarks: A Focus On The Irish Electrical Energy Market, Tony Kealy

Articles

The installed capacity of wind turbines in Ireland increased from a value of 2,250 MW in 2014 to 3,318 MW in 2017, a 43% increase in the four years, supported through climate mitigation policies. The main aim of this study is to determine if the increase in wind turbine installed capacity is impacting on efforts to reduce CO2 emissions. The study utilises a review methodology. The findings show that the steady rise in wind turbine installed capacity year-on-year is not reflected in the Irish CO2 g/kWh energy benchmark. The benchmark value was 457 g CO2/kWh in 2014 and 437 g …

Improving Operator Situation Awareness By Phasor Measurement Unit (Pmu) Data Visualization, Esa M. Rantanen, Ernest Fokoue, Jacob Haut, Chandini Ramesh, Kathleen Gegner, Thomas Overbye, Komal Shetye

Articles

The application of phasor measurement unit (PMU) data in the power industry is currently an area of intense interest. The key driver for PMU technology is to use the precise time sources provided by Global Positioning System (GPS) satellites to accurately measure the relative voltage and current phase angles at buses across an interconnect at a very high sampling rate. Presenting PMU data to power system operators in a format that is truly useful for them and that affords improved situation awareness (SA) and fast and accurate decision making is a particular challenge to display design. This report describes development …

Stakeholder Outcomes In A Wind Turbine Investment; Is The Irish Energy Policy Effective In Reducing Ghg Emissions By Promoting Small-Scale Embedded Turbines In Sme's?, Tony Kealy

Articles

As a member state of the European Union (EU), Ireland has adopted an energy policy which includes promoting wind powered electricity generators as an economically viable, GHG-reducing, alternative to environmentally damaging fossil-fuel driven electrical generators. This longitudinal, inductive in-depth study investigates the outcomes for the government and other stakeholders involved in a wind turbine project investment by a Small-to-Medium-Enterprise (SME) based in rural Ireland. A case study research methodology is used to acquire and analyse quantitative numerical data from multiple sources including electrical power and energy meters, historical electricity bills and company sustainability reports. The study found that the installation …

Technological Assessment Of Different Solar-Biomass Systems For Hybrid Power Generation In Europe, C. M. Iftekhar Hussain, Brian Norton, Aidan Duffy

Articles

Solar Tower thermal (ST), Parabolic Trough thermal (PT), Linear Fresnel thermal (LF) and Solar PV are discussed in the context of suitability for hybridization with biomass in Europe. Technical, economical and climate data have been compared to identify the key drivers of technology selection in setting up large scale solar-biomass hybrid power plants. The sole solar-biomass hybrid power plant is currently in operation in Spain uses PT technology due to its performance characteristics, comparatively easy installation process compared to ST and relatively higher heat and optical gain than LF. The climate condition in the EU shows that the region within …

State-Of-The-Art Review Of Cathodic Protection For Reinforced Concrete Structures, Aimee Byrne, Niall Holmes, Brian Norton

Articles

Cathodic protection (CP) limits the corrosion of a metal surface by making it the cathode of an electrochemical cell. This can be achieved either by using a more active sacrificial anode to create a driving current, or by using inert anodes and impressing a current onto the cathode surface using an external direct current (DC) source. Impressed current cathodic protection (ICCP) is preferred where widespread protection is required, particularly in reinforced concrete structures. ICCP needs a constant DC power supply that is usually provided through a grid connection or independent generators. This paper presents the currently available CP systems for …

Improving Operator Situational Awareness With Wide Area Geographic Data View Displays Of The Electric Power Grid, Esa M. Rantanen, Limor Hochberg, Diego Klabjan, Mingyang Di

Articles

To reduce clutter on wide-area geographic data view displays of electric power systems, substations in geographically compact areas should be spread out and line overlaps and intersections minimized. Such pat- terns optimized with respect to given constraints can be modeled as a multicommodity flow problem. Due to the size of the developed model, we developed two clustering-based iterative algorithms to decompose the global network into smaller regions and then iteratively solve the subproblem in each region by readjusting some values. Three solutions were selected for experimental evaluation. The experimental results were somewhat inconclusive, due to naïve participants, simple task, and …

A Clustering Approach To Domestic Electricity Load Profile Characterisation Using Smart Metering Data, Fintan Mcloughlin, Aidan Duffy, Michael Conlon

Articles

The availability of increasing amounts of data to electricity utilities through the implementation of domestic smart metering campaigns has meant that traditional ways of analysing meter reading information such as descriptive statistics has become increasingly difficult. Key characteristic information to the data is often lost, particularly when averaging or aggregation processes are applied. Therefore, other methods of analysing data need to be used so that this information is not lost. One such method which lends itself to analysing large amounts of information is data mining. This allows for the data to be segmented before such aggregation processes are applied. Moreover, …

Lighting Design In Europe: Aligning The Demands For Lower Energy Usage With Better Quality., Kevin Kelly, James Duff

Articles

Lighting design is one of the fastest changing areas in building engineering. It has evolved significantly in recent years due to changing technology and demands for improved quality, better control, reduced energy and sustainability. This paper is an overview of what is happening in Europe and elsewhere and examines the literature to find that latest recommendations in the Code for Lighting issued by the SLL (Society of Light and Lighting) in the UK change previous demands for equal illuminance across a working plane to more specific and demanding criteria. There are recommendations for qualitative metrics and better distribution of light …

Small Wind Turbines In Turbulent (Urban) Environments: A Consideration Of Normal And Weibull Distributions For Power Prediction, Keith Sunderland, Thomas Woolmington, Jonathan Blackledge, Michael Conlon

Articles

The urban terrain and the associated morphological complexities therein, present significant challenges for the deployment of small wind turbines. In particular, a considerable amount of uncertainty is attributable to the lack of understanding concerning how turbulence within urban environments affects turbine productivity. Current wind turbine power output measurements (particularly for small/micro wind turbines) are based on an average wind speed over an observation period; with limited accountability of the variability of wind speed within the observation time frame. This paper however, presents two models that can instead accurately consider such wind speed variation and how it affects the turbine, based …

Maximising Value Of Electrical Networks For Wave Energy Converter Arrays, Fergus Sharkey, Elva Bannon, Michael Conlon, Kevin Gaughan

Articles

Currently there are the beginnings of a commercial wave energy industry and the ultimate ambition will be to deploy Wave Energy Converters (WECs) in arrays, or wave farms, in a similar fashion to offshore wind. These arrays will require electrical networks to collect and export the generated electrical power to shore and onto the electrical grid. For large scale wind farms the inter-array and export electrical networks can represent more than 20% of the project’s capital expenditure. Submarine power cables account for a large proportion of this cost. The same is expected to be the same for WEC arrays.

This …

Resource-Induced Voltage Flicker For Wave Energy Converters – Assessment Tools, Fergus Sharkey, Joe Macenri, Elva Bannon, Michael Conlon, Kevin Gaughan

Articles

For wave energy converters, the input resource has a typical period of 5–20 s depending on the site location and dominant seastates. Wave energy converters generally produce mechanical power twice per wave cycle and therefore depending on the storage available, the electrical power output has half the period of the input resource. These regular power changes induce a voltage change at the point of connection (POC) which is proportional to the amplitude of the power change and at the same frequency. Therefore the coupling of the input resource to the output power of a wave energy converter will cause voltage …

Evaluation Of Time Series Techniques To Characterise Domestic Electricity Demand, Fintan Mcloughlin, Aidan Duffy, Michael Conlon

Articles

This paper discusses time series approaches, often used by Transmission System Operators (TSOs) to forecast system demand, and applies them at an individual dwelling level. In particular, two techniques, Fourier transforms and Gaussian processes were evaluated and used to characterise individual household electricity demand. The performance of the characterisation approaches were evaluated based on Pearson correlation coefficient, descriptive statistics and paired sample t-tests for electrical parameters: Total Electricity Consumption, Maximum Demand, Load Factor and Time of Use of maximum electricity demand. Finally, a number of time series tests were carried out to ensure certain properties remained between the original and …

Enhancing The Performance Of Building Integrated Photovoltaics, Brian Norton, Philip C. Eames, Tapas K. Mallick, Ming Jun Huang, Sarah J. Mccormack, Jayanta D. Mondol, Yigzaw G. Yohanis

Articles

Recent research in Building Integrated Photovoltaics (BIPV) is reviewed with the emphases on a range of key systems whose improvement would be likely to lead to improved solar energy conversion efficiency and/or economic viability. These include invertors, concentrators and thermal management systems. Advances in techniques for specific aspects of systems design, installation and operation are also discussed.

Measured Performance Of A 1.72 Kw Rooftop Grid Connected Photovoltaic System In Ireland, Lacour Ayompe, Aidan Duffy, Sarah Mccormack, Michael Conlon

Articles

This paper presents results obtained from monitoring a 1.72 kWp photovoltaic system installed on a flat roof of a 12 m high building in Dublin, Ireland (latitude 53.4 N and longitude 6.3 E). The system was monitored between November 2008 and October 2009 and all the electricity generated was fed into the low voltage supply to the building. Monthly average daily and annual performance parameters of the PV system evaluated include: final yield, reference yield, array yield, system losses, array capture losses, cell temperature losses, PV module efficiency, system efficiency, inverter efficiency, performance ratio and capacity factor. The maximum solar …

Transparent Patch Antenna On A-Si Thin Film Glass Solar Module, Maria Roo Ons, S. Shynu, Max Ammann, Sarah Mccormack, Brian Norton

Articles

An optically transparent microstrip patch mounted on the surface of a commercially available solar module is proposed. The patch comprises a thin sheet of clear polyester with a conductive coating. The amorphous silicon solar cells in the module are used as both photovoltaic generator and antenna ground plane. The proposed structure provides a peak gain of 3.96 dBi in the 3.4-3.8 GHz range without significantly compromising the light transmission in the module. A comparison between copper and transparent conductors is made in terms of antenna and solar performance. The proposed technique is considerably simpler that previous integration approaches.

Parallel Operation Of Inverters And Active Power Filters In Distributed Generation System: A Review, Shafiuzzaman Khan Khadem, Malabika Basu, Michael Conlon

Articles

In this paper a technical review of parallel operation of power electronics inverters for load sharing conditions in distributed generation (DG) network is presented. Emphasis is given to parallel operation of Active Power Filters (APFs) as they are widely used to mitigate load current disturbances into DG networks. Discussions on recent advances in control strategies as applied to APFs are presented.

The Generation Of Domestic Electricity Load Profiles Through Markov Chain Modelling, Fintan Mcloughlin, Aidan Duffy, Michael Conlon

Articles

Micro-generation technologies such as photovoltaics and micro-wind power are becoming increasing popular among homeowners, mainly a result of policy support mechanisms helping to improve cost competiveness as compared to traditional fossil fuel generation. National government strategies to reduce electricity demand generated from fossil fuels and to meet European Union 20/20/20 targets is driving this change. However, the real performance of these technologies in a domestic setting is not often known as high time resolution models for domestic electricity load profiles are not readily available. As a result, projections in terms of reducing electricity demand and financial paybacks for these micro-generation …

Validated Real-Time Energy Models For Small-Scale Grid-Connected Pv-Systems, Lacour Ayompe, Aidan Duffy, Sarah Mccormack, Michael Conlon

Articles

This paper presents validated real-time energy models for small-scale grid-connected PV-systems suitable for domestic application. The models were used to predict real-time AC power output from a PV system in Dublin, Ireland using 30-min intervals of measured performance data between April 2009 and March 2010. Statistical analysis of the predicted results and measured data highlight possible sources of errors and the limitations and/or adequacy of existing models, to describe the temperature and efficiency of PV-cells and consequently, the accuracy of power prediction models. PV-system AC output power predictions using empirical models for PV-cell temperature and efficiency prediction showed lower percentage …

Development Of A 12 Kva Dsp-Controlled Laboratory Prototype Upqc, Iurie Axente, Jayanti Navilgone Ganesh, Malabika Basu, Michael Conlon, Kevin Gaughan

Articles

This paper reports the development of a laboratory prototype of a fully digital DSP-controlled 12-kVA unified power quality conditioner (UPQC), capable of compensating for both the supply voltage and the load current imperfections. A fully digital controller based on the TMS320F2812 DSP platform is implemented for the reference generation as well as control purposes. The delay problem in the digital controller is overcome by application of a fast DSP, a compact control technique and proper flow of control steps in the DSP software. A phase-locked loopless software grid synchronization method has been implemented for the effective operation of the UPQC …

Projected Costs Of A Grid-Connected Domestic Pv System Under Different Scenarios In Ireland, Using Measured Data From A Trial Installation, Lacour Ayompe, Aidan Duffy, Sarah Mccormack, Michael Conlon

Articles

This paper presents results of a study of projected costs for a grid-connected PV system for domestic application in Ireland. The study is based on results from a 1.72kWpPV system installed on a flat rooftop in Dublin, Ireland. During its first year of operation a total of 885.1kWh/kWp of electricity was generated with a performance ratio of 81.5%. The scenarios employed in this study consider: a range of capital costs; cost dynamics based on a PV module learning rate of 2+/-75%; projections for global annual installed PV capacity under an advanced and moderate market growth conditions; domestic electricity cost growth …