State-of-the-Art Renewable Energy in Korea

Nowadays, renewable energy plays an important role in our daily lives. This Special Issue addresses the current trend in the use of renewable energy in South Korea. The first aspect is a renewable-based power system, where both main and ancillary supplies are sourced from renewable energies; the second aspect is a distribution network for renewable energy; and the last aspect is a nanogrid network technology. Renewable energy requires many innovations over existing power infrastructure and regulation. These articles show the changing trend in various sectors in Korea

Strategic initiatives to increase the uptake of rooftop photovoltaic systems

This thesis has focused on the strategies that can be implemented by electricity utilities and private investors in increasing the penetration of rooftop photovoltaic systems (RPVs). Even though the proposals are general and applicable for any locality, the key studies of this research have been focused on the Australian electricity market. First, a detailed review and comparison of all Australian power distribution companies has been carried out in terms of the percentage of the supplied customers and the customer density per kilometre length of their power lines. Following that, the daily electricity supply and the electricity unit charges offered by the active electricity retail companies in the zones of each of these power distribution companies are reviewed and compared. Based on this information, the annual electricity bill of a customer supplied by different power distribution companies and retailers is calculated. Through this study, the national average annual electricity bill has been determined for Australia and the power distribution companies are categorised under four segments of very cheap, cheap, expensive, and very expensive companies. This study has highlighted some of the key challenges faced by power distribution companies in Australia in supplying power through a more localised renewable based generation. Installing an RPV by a household is a big decision, and there are many factors which need to be considered before this decision. It can be highly rewarding in some cases and for others, it may bring a loss in the investment. The main factors which need to be considered are the electricity consumption tariff, electricity consumption pattern, the location of the household and the tariffs offered by the utility in that area. In this thesis, economic incentives of installing a RPV and battery energy storage (BES) are discussed for a household in different states, served by various utilities. A comparison is made to find which states are more suitable in terms of gaining financial benefits from RPVs. A flat rate feed-in tariff is an incentive offered by many utilities to encourage their customers to invest in electricity generation from RPVs. Such a scheme is usually designed by financial techniques that mostly consider the initial capital cost and electricity spot price. However, such an incentive cannot help the utilities to address the technical challenges in networks with large renewable penetration. In this thesis, a dynamic feed-in tariff has been proposed and designed based on the value of electricity, hosting capacity, ambient temperature and time of day. This feed-in tariff will specifically support utilities that experience challenges in the electrification of remote areas or observe excessive stress on their networks at demand peak periods. The proposed feed-in tariff encourages the rural customers to install RPVs while discouraging the urban customers from installing RPVs without BES. Solar leasing is another opportunity to enhance the rapid uptake of RPVs. Even though solar leasing has attracted widespread acceptance in some countries, it has not been successful in being popular in some other places mainly due to lack of awareness of the model and economic viability in relation to outright buying a RPVs. One of the solar leasing models is roof rental in which a company leases the roof of residential premises for installing RPVs and selling the generated electricity to the utility. This thesis has explored an economically viable alternative for roof rental from the perspective of the engaged leasing company. To this end, an economic analysis has been performed to determine the net present value from the roof rental payments and versus different ratings of RPVs, desired interest rate and existing feed-in tariff. Furthermore, a BES can play an important role in realising maximum benefit from RPVs. However, the cost of a BES is comparatively high, and the BES of individual households may not be optimally utilised during a significant portion of the year as there may not be enough generation from RPVs during winter to charge the BES to its full capacity. Community solar on the other hand, if optimally designed, can give the opportunity to use a BES to its maximum capacity. Such systems can benefit many of the remote and rural communities, that are usually supplied by diesel generators, or long traditional distribution lines, which in addition to being expensive often don’t provide the reliability at desired level. These systems can also benefit most of the urban areas since the unmanaged penetration of RPVs has resulted in the undesired duck curve profile in the network. To this end, this thesis has proposed and validated the appropriate design criteria for community solar projects with an aim to improve the network duck curve profile, enable peak-shaving and increase the self-sufficiency of the community

Estimation of PV Systems Power Production Efficiency іn the Dense Urban Development Conditions

The paper describes the preconditions for planning and building an intelligent community of Energy Smart Community. The state of RES sector development, namely, PV stations in the energy structure of the United Energy System of Ukraine, has been characterized. The features of building an Energy Smart Community architecture include an analysis of the possibilities of joining their own generating capacities as an energy component in this system. The energy and economic criteria for such type of intelligent community are described. The article analyzes the foreign experience in building and implementing Energy Smart Community in power systems on the basis as pilot projects NYSEG and SCA for its further scientific research and testing. Using the software module in the Matlab Simulink environment, we have constructed and described the work on the example of an arbitrary PV module, with its principal dependencies being distinguished from the generalized solar insolation index. The obtained data point to all the prerequisites for the possibility of widespread participation of private PV systems of power supply as the main asset of the Energy Smart Community.В роботі описані передумови для планування та побудови розумного співтовариства Energy Smart Community. Охарактеризовано стан розвитку сектора ВДЕ, а саме PV станцій в енергетичній структурі Об’єднаної енергетичної системи України. Особливості побудови архітектури Energy Smart Community передбачає аналіз можливостей приєднання власних генеруючих потужностей в якості енергетичної складової цієї системи. Описані енергетичні та економічні критерії такого приєднання. Проаналізовано наведено іноземний досвід побудови та впровадження Energy Smart Community в енергетичні системи на основі пілотних проектів NYSEG та SCA для подальшого його наукового дослідження та випробування. Звикористанням програмного модуля в середовищі Matlab Simulink побудовано та описано роботу на прикладі довільного PV модуля з виділенням його основних залежностей від узагальненого показника сонячної інсоляції. Отримані дані вказують на всі передумови можливості широкої участі приватних PV систем забезпечення електроенергією в якості основного активу функціонування Energy Smart Communit

Smart Energy Management for Smart Grids

This book is a contribution from the authors, to share solutions for a better and sustainable power grid. Renewable energy, smart grid security and smart energy management are the main topics discussed in this book

Enhancing solar energy generation potential in the villages of Rovaniemi, Lapland

Abstract. This master’s thesis investigated the solar energy potential of future plots in three different village groups in Lapland using existing provisional master plans. The investigation was conducted as part of the SINNI project. The project explores the potential of virtual power plants in the villages of Lapland. The target area of this research was three village groups in the Rovaniemi region around Sinetta, Vikajärvi and Vanttauskoski. The village groups were selected because the buildings form relatively cohesive groups from the point of view of energy generation, and the proximity of the areas to power lines and main roads. The project aims to characterize “SINNI villages”, which are to be defined by indicators such as their energy production potential, as well as geographical features such as location, land use patterns, and suitability of building stock. The expectation is that when defining the economic feasibility of solar power generation in SINNI villages, these criteria could be used as a basis to assess the techno-economic feasibility of similar sites in the future. The solar energy potential was first assessed considering future buildings on the best oriented building plots in the master plans. The hypothetical range of 120–180° from the true north was selected for the analysis as potentially feasible orientations for solar energy generation. The estimated solar energy potential for the future plots in the three village groups, considering this range of azimuths were 1.07GWh/year for Sinetta, 0.57GWh/year for Vikajärvi and 1.04GWh/year for Vanttauskoski. Secondly, the solar energy potential of all building plots in the 3 village groups were calculated to observe the difference in output. It was found that the solar energy potential of all future plots in the three Village Groups were 1.20GWh/year, 0.71GWh/year,1.47GWh/year respectively. The small differences observed were due to the fact that the majority of the future buildings in the master plans were adjusted well enough to support solar energy generation. Due to the Northern location of the villages, the issue of snow on the panels were also investigated, to ascertain missed solar energy generation potential attributed to snow covering the panels. The results show that 28.3% of the solar energy generation in Spring could be lost due to snow, if effective mitigation strategies are not implemented. The profitability of the solar investments was also analysed using Finsolar Profitability Calculator, from the perspective of homeowners. The results of this research indicate that deploying rooftop solar panels makes economic sense, if the roofs are in the 120–210° azimuth range, as this would provide a relatively fair payback period in the range of 19–23 years. Azimuths out of this range typically result in significantly higher payback period. The use of self-generated energy was also assessed and the consumption profiles for the village groups were analysed in juxtaposition with the self-produced energy under the framework of energy communities. The results show that solar power investments could be economically profitable even in Lapland, if the houses and roofs are sited optimally. The research also indicates that the energy community concept which have been brought into limelight in recent EU directives could potentially enhance the profitability of solar investments by facilitating energy sharing within the community which maximises the value of solar energy produced. They also potentially enhance customer participation, energy security, independence, efficiency, and sustainability which could be regarded as some of the most crucial goals in the energy sector for EU Member States

Hosting Capacity Assessment of Distribution Systems

The increasing penetration of distributed energy resources (DERs) in distribution systems may result in a number of technical problems such as over-voltage, overloading, maloperation of protection systems and power quality issues. One approach to address the above-mentioned issues is upgrading the distribution network, which is quite costly. The second approach is to limit the penetration of DERs to the hosting capacity (HC), which is defined as the maximum DER capacity that can be installed in a system without violating the operational constraints. Understanding this concept can assist utilities to ensure the reliable operation of the system. There have been different studies to identify the HC in a system. Nevertheless, the uncertainties associated with the DERs and loads have not been addressed properly in such studies. Besides, it is very difficult to quantify the findings of those studies and make general conclusions, as they were often based on specific networks, while their methods is time consuming in a big distribution network. Furthermore, the impact of voltage control schemes and emerging technologies, such as electric vehicles (EVs) and battery energy storage systems (BESSs) on the HC have not been studied, adequately. Thus, in this thesis, we propose a suitable HC assessment framework, as well as utilize some of the conventional and emerging resources to increase the HC

Bidding strategy for a virtual power plant for trading energy in the wholesale electricity market

Virtual power plants (VPPs) are an effective way to increase renewable integration. In this PhD research, the concept design and the detailed costs and benefits of implementing a realistic VPP in Western Australia (WA), comprising 67 dwellings, are developed. The VPP is designed to integrate and coordinate an 810kW rooftop solar PV farm, 350kW/700kWh vanadium redox flow batteries (VRFB), heat pump hot water systems (HWSs), and smart appliances through demand management mechanisms. This research develops a robust bidding strategy for the VPP to participate in both load following ancillary service (LFAS) and energy market in the wholesale electricity market in WA considering the uncertainties associated with PV generation and electricity market prices. Using this strategy, the payback period can be improved by 3 years (to a payback period of 6 years) and the internal rate of return (IRR) by 7.5% (to an IRR of 18%) by participating in both markets. The daily average error of the proposed robust method is 2.7% over one year when compared with a robust mathematical method. The computational effort is 0.66 sec for 365 runs for the proposed method compared to 947.10 sec for the robust mathematical method. To engage customers in the demand management schemes by the VPP owner, the gamified approach is adopted to make the exercise enjoyable while not compromising their comfort levels. Seven gamified applications are examined using a developed methodology based on Kim’s model and Fogg’s model, and the most suitable one is determined. The simulation results show that gamification can improve the payback period by 1 to 2 months for the VPP owner. Furthermore, an efficient and fog-based monitoring and control platform is proposed for the VPP to be flexible, scalable, secure, and cost-effective to realise the full capabilities and profitability of the VPP

Methodology for an optimal deployment of the recharging infrastructure for electric vehicles

184 p.CO2 emissions must be reduced to meet the international commitments to tackle climate change. One of the most promising alternatives for such reduction is the electrification of transport, especially in urban environments, due to its advantages in terms of lack of local emissions and noise reduction. Yet, the lack of publicly accessible charging infrastructure is preventing the mass-adoption of electro-mobility. EV customers want to see a dense enough publicly accessible charging infrastructure network, but they will seldom use it if they can use private home charging. Hence, the economic feasibility of deploying such charging infrastructure must be carefully assessed. Although there have been several attempts to assess the economic performance of operating publicly accessible charging infrastructure, none of them if able to handle the complexity of electro-mobility (by e.g. merging all different charging alternatives into the same analysis). This thesis aims at filling the identified gap, by defining a new methodology which looks at the whole value chain, is business-oriented, performs a quantitative analysis, compares EV against ICE vehicles and takes into account the relationships between the different charging alternatives into a single assessment. The three main contributions of the thesis are: 1) The new methodology extends the scope for analysing complex business cases to consider the different dimensions of the business case at the same time, 2) This new methodology highlights the crucial need to involve appropriate representatives of the relevant stakeholders (decision-makers) in the analysis from the very beginning of the process, and 3) The new methodology has an oriented, tailored approach from the early stages of the analysis to obtain significant results which increase the reliability of the outcomes and guide the decision-making process

Deep Reinforcement Learning for Distribution Network Operation and Electricity Market

The conventional distribution network and electricity market operation have become challenging under complicated network operating conditions, due to emerging distributed electricity generations, coupled energy networks, and new market behaviours. These challenges include increasing dynamics and stochastics, and vast problem dimensions such as control points, measurements, and multiple objectives, etc. Previously the optimization models were often formulated as conventional programming problems and then solved mathematically, which could now become highly time-consuming or sometimes infeasible. On the other hand, with the recent advancement of artificial intelligence technologies, deep reinforcement learning (DRL) algorithms have demonstrated their excellent performances in various control and optimization fields. This indicates a potential alternative to address these challenges. In this thesis, DRL-based solutions for distribution network operation and electricity market have been investigated and proposed. Firstly, a DRL-based methodology is proposed for Volt/Var Control (VVC) optimization in a large distribution network, to effectively control bus voltages and reduce network power losses. Further, this thesis proposes a multi-agent (MA)DRL-based methodology under a complex regional coordinated VVC framework, and it can address spatial and temporal uncertainties. The DRL algorithm is also improved to adapt to the applications. Then, an integrated energy and heating systems (IEHS) optimization problem is solved by a MADRL-based methodology, where conventionally this could only be solved by simplifications or iterations. Beyond the applications in distribution network operation, a new electricity market service pricing method based on a DRL algorithm is also proposed. This DRL-based method has demonstrated good performance in this virtual storage rental service pricing problem, whereas this bi-level problem could hardly be solved directly due to a non-convex and non-continuous lower-level problem. These proposed methods have demonstrated advantageous performances under comprehensive case studies, and numerical simulation results have validated the effectiveness and high efficiency under different sophisticated operation conditions, solution robustness against temporal and spatial uncertainties, and optimality under large problem dimensions