Electric Grid Research Articles

Design and evaluation of a standalone electric vehicles charging station for a university campus in Argentina

The increasing popularity of electric vehicles in recent years has led to a growing demand for charging stations. In this context, universities are an ideal setting for their installation, as they have a large number of students, professors, and staff who could benefit from them and, at the same time, it serves as teaching material to raise awareness in the use of renewable energy. This work presents the design and proposal of an electric vehicle charging station for the campus of the Universidad Nacional de Rafaela (UNRaf). The station will be located in an area of the campus where the construction of more buildings and sport facilities is planned. This area will not be connected to the electrical grid and instead, will have an energy storage system to guarantee supply. The station will have the capacity to simultaneously charge 4 bicycles and 2 light electric vehicles, with an average energy demand of 0.786 kWh per hour. Homer Pro software was used for the calculations. The most economically viable option was a 100% renewable solution powered only by solar energy. It is expected to consist of a 15-kW solar system that will produce 22,922 kWh/year and a bank of 30 batteries of 3 kWh plus a single battery of 1 kWh. The installation of the electric vehicle charging station on the UNRaf campus will contribute to promoting the adoption of sustainable transportation, which will help reduce greenhouse gas emissions without using the public power grid.

Rapid remote volcanic ashfall impact assessment for the 2022 eruption of Hunga volcano, Tonga: a bespoke approach and lessons identified

When disasters occur, rapid impact assessments are required to prioritise response actions, support in-country efforts and inform the mobilisation of aid. The 15 January 2022 eruption of Hunga volcano, Tonga, and the resulting atmospheric shockwave, ashfall, underwater mass disturbance and tsunami, caused substantial impacts across the Kingdom of Tonga. Volcanic impacts on the scale observed after the eruption are rare, necessitating a reliance on international advice and assistance. The situation was complicated by the loss of Tonga’s international submarine fibreoptic cable (causing a complete loss of communications for approximately 20 days) along with border closures due to the COVID-19 pandemic. A need emerged for a rapid remote volcanic impact assessment and provision of specialist advice to help inform the response of international partners. Here we present a novel methodology for conducting rapid remote volcanic ashfall impact assessments, conducted over a 10-day period following the eruption. We used three different hazard models for ashfall thickness across the main island of Tongatapu and available asset information and vulnerability functions for buildings, agriculture, electricity networks, water supply and roads, to provide initial estimates of losses due to ashfall from the 15 January eruption. For buildings, we estimated losses both as total losses and as percentages of the total replacement cost of buildings on Tongatapu. For agriculture, we made probabilistic estimates of production losses for three different crop classes. For ashfall clean-up, we estimated ranges of ashfall volumes requiring clean-up from road surfaces and roofs. For water supply, electricity networks and roads, our analysis was limited to assessing the exposure of important assets to ashfall, as we had insufficient information on system configurations to take the analysis further. Key constraints on our analysis were the limited nature of critical infrastructure asset inventories and the lack of volcanic vulnerability models for tropical regions including Pacific Island nations. Key steps towards iteratively improving rapid remote impact assessments will include developing vulnerability functions for tropical environments as well as ground-truthing estimated losses from remote approaches against in-person impact assessment campaigns.

Quantitative analysis of high-frequency radiometric databases. Application to the case of Seville

AbstractThe short-term variability of solar resource is one of the main challenges faced by the large-scale implementation of photovoltaic (PV) systems today; this will increase as the installed power of solar PV increases. To evaluate its influence on electrical grid operation, it is essential to analyse the variability of solar resource based on high-frequency data, 30 s and shorter. In this study, the high-frequency measurements of Global Horizontal Irradiation (GHI) and Direct Normal Irradiation (DNI) recorded every 5 s at the radiometric station of the University of Seville for 20 years are analysed and characterised. For this purpose, a corrected database for GHI and DNI was obtained from the application of a correction methodology. To understand the reliability of this database it is required to know its uncertainty. This work proposes a methodology to quantify the uncertainty of high-frequency radiometric databases whose wrong data have been corrected. Applying it, the daily uncertainty is 2.69% for GHI and 4.07% for DNI. To characterize the distribution of the database, the distribution of high frequency kt and kb indices are modelled providing the fitting parameters. To characterize the variability of high-frequency measurements, transition matrices are proposed, which allow identifying both the magnitude and frequency of jumps. The results obtained show that jumps of up to 800 W/m2 occur in both GHI and DNI. In the case of GHI, the percentage of jumps equal to or greater than 500 W/m2 is 1.36%, about 43,000 jumps in a year in measurements every 5 s.

The Application and Challenges of Vehicle-to-Grid (V2G) Technology in the Development of New Energy Vehicles

Abstract: The global automotive industry has entered a phase of energy-saving and low-carbon development, with the advancement of new energy vehicles becoming the strategic direction for automotive industries worldwide. However, the large-scale integration of electric vehicles into the power grid has imposed significant challenges on the operation of the electrical grid. This article analyzes Vehicle-to-Grid (V2G) technology, introducing its main functions, key technologies, and advantages, and outlines the current state of its application both domestically and internationally. Additionally, the obstacles hindering the development of V2G technology in China are examined, and several strategies to accelerate the development of V2G technology in China are proposed. It is hoped that these measures will encourage both the government and enterprises to take active steps towards promoting the rapid development of V2G technology.

Clean energy transition in rural Bangladesh: Challenges in adoption and impact

ABSTRACT At the household level, the solar photovoltaic (PV) system is an off-grid clean energy source with significant poverty reduction potential, thereby contributing to the attainment of several sustainable development goals. Nevertheless, there has been limited adoption of renewable or clean energy technologies in Bangladesh. At present, renewable energy sources account for only 3% of the country’s electricity generation. This study thus investigates the drivers of solar PV adoption and the impact of this on household income and poverty in Bangladesh. We present an econometric analysis of data from the International Food Policy Research Institute’s Bangladesh Integrated Household Survey, 2020. Our findings indicate that only 5.51% of the sample households adopted solar PV, with the likelihood of adoption 3.8% higher in households with a mobile phone, 1.7% higher in households with internet access, and 2.8% higher among homeowners. However, the government’s programs to expand the electricity grid made the delivery of solar PV by partner organizations less competitive. Our analysis reveals that the adoption of solar PV has a positive effect on household income of between 9.31% and 13.50%. The poverty gap is likely to decrease by around 20% to 26% due to adoption. These findings are pertinent to ongoing policy development efforts targeted at increasing the adoption of renewable energy to meet the sustainable development goals. Solar PV information could be potentially disseminated through mass media and modern communication technologies that require internet access. Furthermore, increasing the installation of solar PV systems in rented houses may promote the adoption of solar PV. It is imperative to implement policies that provide incentives for the installation and utilization of solar PV.

E-learning Supporting Infrastructure Investment in South Africa: Perspective of a Developing Economy

South Africa is one of the developing economies. Most of its provinces are in rural areas and have poor or lack of reliable critical infrastructure to enable development as in the case of urban areas. Infrastructure refers to physical structures that serve as the underlying foundation for the functioning of an economy. It includes physical facilities such as communication systems (telephone lines, broadband), and power supply systems (electrical grids, dams, etc.). The focus of the study is on information communication technological infrastructure (ICT) such as telephone and broadband networks and electricity infrastructure that support the adoption of e-learning. Many schools in South Africa are in rural areas and are attended by the majority of learners. These learners should perform the same way as learners in urban schools. Urban schools have better access to ICT infrastructure. Due to a lack of equitable ICT infrastructure, many education institutions back-tracked from the hybrid teaching mode implemented during the coronavirus (COVID-19) lockdown to the traditional class/lecture-room mode of teaching. It is revealed in the study that South Africa struggles in the area of infrastructure development. These affect the achievement of sustainable development goals (SDGs) which are heavily dependent on infrastructure, including education. E-learning offers a better advantage compared to traditional class/lecture-room-based education. ICT infrastructure that supports the provision of e-learning is not equitably distributed, and those that are available are not enough and reliable. South Africa is reported to need R4.8 trillion to achieve its critical infrastructure goals, indicating a dire need for infrastructure investment. Under-investment in infrastructure affects all sectors of the economy, including the education sector.

A novel model for rural household photovoltaic market trading: Utilizing cooperative alliances within a peer-to-peer framework

In the face of diminishing traditional subsidy models and the constraints of grid-dependent transactions, this study explores trading models as a catalyst for rural electrification and sustainable development in China. Highlighting the emergence of rural photovoltaic (PV) prosumers, we propose trading models through cooperative alliances to facilitate market engagement within a peer-to-peer (P2P) framework. By applying the Shapley value for the equitable distribution of internal revenues, the study elucidates the complex interrelations between rural prosumers and the electrical grid, fostering a better understanding of their mutual interests. Further, we introduce a dynamic game-theoretic model to investigate the evolving market behaviors under diverse strategic influences among rural prosumer groups and the grid. Using numerical simulations based on real-world data from Shanghang County, Fujian Province, we analyze surplus and deficit electricity production scenarios within these alliances. The findings underscore the effectiveness of the cooperative alliance trading model in aligning individual, collective, and societal benefits. This comparative analysis of strategic outcomes validates the model's feasibility and role in advancing sustainable rural electrification strategies.

A cooperative approach for generation and lines expansion planning in microgrid‐based active distribution networks

AbstractWith the growth of the load in the electricity networks, sufficient investment in the generation and lines expansion should be made in order to provide the energy needed by consumers with the lowest possible investment and operation costs. This issue is especially important in distribution networks, which are faced with the uncertainties of renewable energy generation and the development of microgrids and related issues.In this article, the planning of generation and lines expansion has been modeled with the aim of minimizing the total costs of microgrids, based on the cooperative approach. For this purpose, a bi‐level model has been developed; on the upper level, microgrids make investment decisions with a cooperative approach, and a constrained stochastic formulation has been developed with considering operational uncertainties on the lower level. Also, in this article, in order to ensure the supply of critical loads in island conditions, the self‐sufficiency index is defined. Three case studies have been considered to ensure the effectiveness of the developed model. In case 1, each microgrid will be able to supply its load only by generating of its units and purchasing from the retail market. In case 2, the possibility of trading with other microgrids in a non‐cooperative approach will also be available to the microgrids operators, and in case 3, microgrids can exchange energy with other microgrids in a cooperative manner. The simulation results showed that due to the possibility of using nearby microgrid resources, the cost of microgrid load supply in case 2 was reduced by 4.84% compared to case 1. Also, this cost in case 3 was reduced by 5.23% and 0.38%, respectively, compared to cases 1 and 2, due to the use of a cooperative manner in microgrid load providing.

Integration of Renewable Energy Solutions in Agricultural Operations

The integration of renewable energy solutions in agricultural operations presents a transformative approach to enhancing sustainability, reducing greenhouse gas emissions, and improving the economic viability of farming practices and explores the various renewable energy technologies applicable to agriculture, including solar, wind, biomass, and biogas energy solutions. Each technology is examined for its specific applications within the agricultural sector, highlighting its potential benefits and the challenges faced in implementation. Solar energy, through photovoltaic and thermal systems, offers significant potential for powering irrigation, greenhouse operations, and processing facilities, thereby reducing reliance on fossil fuels and grid electricity. Wind energy, with its ability to generate electricity through turbines, is particularly valuable in regions with consistent wind patterns, contributing to both onfarm energy needs and grid supply. Biomass energy, utilizing agricultural residues and dedicated bioenergy crops, provides a sustainable solution for heating and energy generation, while also addressing waste management challenges. Biogas production, through anaerobic digestion of organic waste, presents a dual benefit of generating renewable energy and improving nutrient recycling in farming systems. Government subsidies, feedin tariffs, research funding, and technical support play pivotal roles in encouraging farmers to transition to renewable energy sources. Case studies from various regions illustrate the practical implementation of these technologies, demonstrating their impact on enhancing agricultural productivity, reducing environmental footprints, and fostering energy independence, including policymakers, researchers, and farmers, about the opportunities and challenges in adopting sustainable energy practices. The findings underscore the importance of continued innovation, supportive policies, and collaborative efforts to achieve a resilient and sustainable agricultural sector.

Scales of accountability: Solar mini-grids and clean energy for all in Uganda

There is great hope pinned on solar mini-grids to fulfil universal rural electrification targets and enable clean energy access, especially in low-income African countries such as Uganda. Yet Ugandan realities are complex, with many unelectrified households in villages the electric grid serves, and varied experiences with the few solar mini-grids implemented in recent years, indicating limited downward accountability. Crucially, large solar plants have arrived, making it timely to resolve the dilemma of just clean energy provision both in and from rural areas. Yet little research on energy transitions in this context exists to explain its political economic complexity. We draw on field visits to three solar mini-grids with contrasting performances, to Uganda's largest 20 MW solar plant, through dozens of villages, and on meetings with the regional utility and the Ministry of Energy and Mineral Development. This is supplemented by knowledge of Uganda's energy policy through document analysis and lived experience. We adapt accountability analysis to deploy a novel ‘scales of accountability’ framework at multiple spatial scales of solar deployment. Our analysis offers insights on the challenges Uganda must address to achieve the potential associated with solar mini-grids and multi-scalar solar energy transitions to achieve universal clean energy access.

Tackle power outage effects for Egypt's energy crisis via localized optimum load shedding

This paper presents an approach for selecting optimal load-shedding values for individual subscribers or consumers. Implementing this method can bring positive outcomes for consumers by minimizing risks and economic losses caused by power outages. It enables network operators to address power supply deficits and overcome network issues, especially those affecting weaker areas. The optimal load-shedding values are determined by employing IGWA (Improved grey wolf algorithm) through a Graded Objective Function Strategy. The proposed method essentially centered on categorizing loads into two levels based on their importance. The first level includes essential loads, the disruption of which results in risks or significant economic losses. The second level comprises less critical loads, and they do not have more risks or economic losses when power outages. This approach applies specifically to residential loads. The control scheme diagram of disconnecting and reconnecting the current is established by estimating the critical load limit during power outage periods. The necessary arrangements can be made, leading to a proactive measure against risks and losses. The proposal has been implemented in Egypt's electricity network. this proposed method provides a simple and effective solution to the ongoing crisis and provides permanent resolution of problems arising from power outages.

Modelling Nigerian residential dwellings: bottom-up approach and scenario analysis

Nigeria’s residential buildings consume a substantial amount of the country’s energy, so achieving a net-zero building sector with a rapidly growing population is a key challenge. To bridge the gap in research at a national level and support Nigeria’s commitment to an unconditional 20% reduction in emissions by 2030, this study develops bottom-up archetype models of different residential building typologies to estimate the energy and material use of Nigerian residential buildings. This creates an overview of the residential stock and how different archetypes perform. The study calculates a baseline energy and material use of Nigeria’s residential building stock using the BuildME tool and converts these data into CO2 emissions using a life-cycle assessment. Scenarios are modelled for 2020. Nigeria’s residential dwellings use approximately 0.3 kt of material per dwelling over a lifetime of 50 years and 2404 kWh/yr of energy per dwelling. Annualised, dwellings emit 2500 kgCO2-eq per dwelling due to material and energy use. Scenarios proposed for meeting Nigeria’s emissions targets will require improved energy efficiency, decarbonising the building envelope through a shift in construction materials and decarbonising grid electricity. Policy relevance This study provides a comprehensive analysis of the energy and material use of residential buildings in Nigeria, focusing on achieving the country’s commitment to a 20% reduction in emissions by 2030. It employs a bottom-up approach to model energy and material use, revealing the peculiarities of the dwelling stock across Nigeria’s four climatic zones. The study explores the implications of different policy scenarios on sustainable housing. The research suggests that meeting Nigeria’s emissions targets requires improved energy efficiency, a shift in construction materials and decarbonisation of grid electricity. It also highlights the potential benefits of a policy switch to materials such as timber, earthen blocks, adobe bricks and clay, which could significantly reduce construction-related emissions. These changes could improve the quality of life of households in Nigeria, combat climate change on a global scale and bring economic advantages to Nigeria.

Energy Transition Policy of the Mexican Electricity Sector: A Representation in Terms of the Theory of Change

Energy transition in the electricity sector is central to limiting global warming to 1.5 °C. Countries around the world rely on official planning documents, such as strategies, special programs, and action plans, to guide these efforts. However, there are few systematic approaches and tools that can help policy makers determine comprehensiveness, coherence, consistency, and coordination when designing these planning documents. This represents a risk to meet energy transition and climate change goals if the relationships of policies and actions included in these documents are not addressed properly. To this end, this paper proposes an approach to model hierarchical relationships using the theory of change, while causal relationships are allocated using policy makers’ experience (yet can also be exogenously allocated using other models). As a case study, this work investigates Mexico’s energy transition policy of the electricity sector over the 2013–2018 period. The results show that Mexico’s official planning documents lack a good design since most policies and actions are not articulated in the right sequence and privilege clean centralized and distributed generation and energy efficiency, while others related to the modernization of electrical grids and climate and environmental policies are barely included.

Overview of Key Technologies for Wind Energy Applications

Due to the pursuit of economic benefits and the development and damage to the environment, the need to develop new energy sources is increasing day by day. as one of the earliest and most mature new energy generation methods, wind power has received much attention. However, wind power generation system is constrained seriously by the environment because of the random fluctuation of wind power itself. It is easy to cause problems such as low power generation efficiency and fast device loss due to the influence of wind instability. At the same time, it is difficult to store and connect electric energy to the electricity grid.

GaN-on-sapphire JTE-anode lateral field-effect rectifier for improved breakdown voltage (>2.5 kV) and dynamic RON

In high-power switching applications such as electric grids, transportation, and industrial electronics, power devices are supposed to have kilo-voltage (kV) level blocking capability. In this work, 1200-V gallium nitride (GaN) lateral field-effect rectifiers (LFERs) are demonstrated. The GaN-on-sapphire epitaxial structure is adopted to prevent vertical breakdown. To address electric field crowding, a p-GaN/AlGaN/GaN junction termination extension (JTE) is embedded in the anode region of the LFER. Comparing to the conventional LFER (Conv-LFER) fabricated on the same wafer, the JTE-anode LFER (JTE-LFER) achieves an improved breakdown voltage (>2.5 kV) and a lower dynamic ON-resistance (RON). The proposed p-GaN/AlGaN/GaN JTE offers a semiconductor-based solution (contrasted to the dielectric-based solution, i.e., field plate) to mitigate the high electric field, which is highly desirable for wide bandgap semiconductor power devices as it enhances the dielectric reliability.

Reducing uncertainties of climate projections on solar energy resources in Brazil.

The share of solar power in Brazil's electrical grid has rapidly increased, relieving GHG emissions and diversifying energy sources for greater energy security. Besides that, solar resource is susceptible to climate change, adding uncertainty to electrical grid resilience. This study uses satellite and reanalysis data to evaluate the performance of CMIP6 models in replicating and predicting surface solar irradiance (SSR) in Brazil. The results from the most reliable models indicate an increase in SSR by 2% to 8% in most regions, with a decrease of around 3% in the South. These findings highlight the potential for increased photovoltaic (PV) yield if backed by supportive public policies while underlining the importance of uncertainty assessment of climate models.

The role of the electricity grid in operation-induced greenhouse gas emissions by a residential building: A multi-year retrospective simulation study

In view of the growing shares of renewables in the electricity grid in combination with the electrification of hvac (heating, ventilation, air conditioning) systems in residential buildings, the grid intensity (in terms of carbon dioxide emissions per unit of electric energy) becomes increasingly sensitive to weather conditions, and synchronicity between weather and the grid becomes a more critical aspect in building performance assessment. Using building performance simulation techniques to seek robust building designs requires awareness about the uncertainties in circumstantial factors that affect performance. This 2016 – 2022 retrospective study highlights the effects of using low or high temporal resolution grid emissions intensity data on projected operation-induced carbon dioxide emissions for a terraced dwelling in the Netherlands. Building fabric quality, the occupant profile, and systems configurations (i.e., hvac and photovoltaics) are varied to investigate the effects of the applied grid model resolution. This study shows that ignoring high-resolution grid intensity data is getting increasingly problematic; applying low resolution (annual) instead of high-resolution (15-minute) grid intensity data leads to an increasingly unjustified optimistic assessment both for net and gross emissions (either or not allowing for carbon displacement by feeding locally generated electricity into the grid).

The impact of North American winter weather regimes on electricity load in the central United States

AbstractExtreme wintertime cold in the central United States (US) can drive excessive electricity demand and grid failures, with substantial socioeconomic effects. Predicting cold-induced demand surges is relatively understudied, especially on the subseasonal-to-seasonal (S2S) timescale of 2 weeks to 2 months. North American winter weather regimes are atmospheric tools that are based on persistent atmospheric circulation patterns, and have been linked to potential S2S predictability of extreme cold in the central US. We study the relationship between winter weather regimes and daily peak load across 13 balancing authorities in the Southwest Power Pool. Anomalous ridging across Alaska, the West Coast, and Greenland drive increases in demand and extreme demand risk. Conversely, anomalous troughing across the Arctic and North Pacific reduces extreme demand risk. Thus, weather regimes may not only be an important long-lead predictor for North American electricity load, but potentially a useful tool for end users and stakeholders.

Domesticating energy flexibility. Learning from great britain’s 2022–2023 demand flexibility service

Demand-response is essential for balancing electricity grids with increasing proportions of intermittent renewable sources of generation. Harnessing the potential for demand-response in domestic settings could deliver widespread benefits for electricity systems and householders. This study applies domestication theory to a major national domestic electricity demand-response programme in Great Britain, exploring how participants integrate demand-response sessions into their everyday routines. The study uses empirical data from twenty-five participants who completed diaries reflecting on their experience of taking part in thirteen demand-response sessions scheduled over a five-month period in winter 2022–23. The study identifies and analyses five pathways for domesticating demand-response, making recommendations to support system-actors in boosting and sustaining the adoption of demand-response. The study concludes that designing electricity demand-response programmes, as a staple of secure low-carbon energy systems, will need to take full account of users’ non-financial motivations, previous experiences of demand-response, and access to enabling technology.

Dynamic performance enhancement of DFIG wind turbine using an active disturbance rejection control -based sliding mode control

The present paper proposes a hybrid control law that combines the active disturbance rejection control (ADRC) and the sliding mode control (SMC) to improve the decoupled control of the active and reactive power stator applied to a doubly-fed induction generator (DFIG) integrated into a wind energy conversion system. The stator is directly connected to the electric grid, while the rotor is connected to the electric grid via a back-to-back converter. The Lyapunov theory proves the stability of nonlinear control. The performance of the proposed strategy is compared with that of traditional ADRC and proportional-integral control (PI). The simulation results in MATLAB/SIMULINK environment using a 1.5MW wind system model show the proposed approach. The proposed algorithm shows an excellent dynamic performance that reduces the time response, overshoot, and steady-state error compared to the conventional controllers.Considering parametric variation, applying a novel controller results in fewer oscillations in stator powers, outperforming the PI regulator and classic ADRC.