National Power System Research Articles

Biomass as a Renewable Energy Source for Power Boilers

The development of photovoltaic systems and wind turbines reduces the carbon footprint (CFP) of energy generation. However, these systems deteriorate the stability of the national power system (NPS). The important stabilizing element of the Polish NPS are coal-fired power plants. Since the cold startup of these units takes several hours, the stability of the NPS forces the boilers to operate so that the power can be increased quickly. Therefore, it will be impossible to abandon coal-fired units in the next years, and the boilers will be modernized to reduce their CFP. An important option is to replace coal with a fuel with a lower CFP, e.g. biomass. This paper deals with the CFP for different types of biomass. It also considers methane emissions from coal mines. The CFP for coal and biomass was compared with the CFP for green ammonia. Using 0-dimensional calculations of the boiler, the need to modernize the heating surfaces was assessed when replacing 50% and more of coal with biomass. The changed fouling of heating surfaces was taken into account. The problem of reducing harmful phenomena such as corrosion, erosion and slagging associated with such a change of fuel is also discussed.

Spatial national multi-period long-term energy and carbon planning scenarios in Ecuador’s electric system

The Republic of Ecuador is developing a comprehensive plan to meet the increasing residential, industrial, and commercial energy demands. With a population of 17.08 million in 2018, the country is experiencing an annual average energy growth of approximately 7.13% until 2027. This research aims to model the incorporation of new and proposed power plants strategically planned to cater to the expanding demand needs. Ensuring that our existing energy infrastructure can adequately meet the current and growing needs of the residential, commercial, and industrial sectors should be made possible. In this paper, we present several hypotheses that need to be made to identify the potential demands for residential, industrial, and commercial requirements, making it more accessible to build new facilities that use renewable energy. Traditional and unconventional renewable energy sources, such as hydro-power, wind, and solar power, are being explored to generate electricity. The research employs quantitative methodology, beginning with gathering information and a detailed data analysis. Subsequently, a scenario-based model will examine the impact on energy demand and supply from 2020 to 2035. The results show that the Santiago hydroelectric project is becoming essential for the country’s energy development and that the current national power system will only be able to supply the electricity demand when the industrial city of Posorja is being developed. We suggest that to maintain Ecuador’s electricity trade balance as an electricity exporter, we continue with the energy investment plans currently issued by the Ministry of Energy and Mines. This study is relevant for establishing global financing arrangements involving the public and private sectors. In doing so, we can meet our hypothetical scenarios, ensuring that all energy needs are met by 2035. This will involve developing a robust national grid system with sufficient reserve capacity, meeting residential and projected commercial and industrial demand.

Development of the Polish Power Sector towards Energy Neutrality—The Scenario Approach

This article discusses three scenarios for the transformation of the Polish power system leading to the achievement of climate neutrality through investment in renewable energy sources. The scenarios differ in terms of the role played by the selected energy technologies. The scenarios were developed using the balancing tool, the Simulator Polish Power System, which analyzed the development of the national power system in terms of optimal costs of achieving climate neutrality and the lowest possible price of electricity generation. The research shows that under Polish climatic conditions, 100% RES energy can be achieved in the balance, but ensuring the continuity of energy supply, which in future will be generated mainly from this type of source, requires the participation of controllable sources such as gas-fired power plants powered by biomethane and energy storage facilities. The scenarios assume balancing RES sources with 15–25 GW of available gas sources and 40 GWh in electricity storage. The article also discusses factors limiting the suggested scenarios, such as the availability of sustainable biomethane in Poland or limitations associated with the possibility of building onshore and offshore wind turbines.

Economic effects of the hydrogen fuel cell sector in South Korea: An input-output analysis

The South Korean government plans to deploy approximately 200–300 MW of hydrogen fuel cells (FCs) annually from 2023 to 2036, all of which will be connected to the national power system, not used for self-consumption. The government is requesting quantitative information on the economic effects of the FC sector. In response to this request, this study delves into the four economic effects of expanding FC use in South Korea adopting the input-output (IO) approach for the first time in the literature. More specifically, it investigates how much investment or production in the FC sector affects other sectors. Economic performance, such as production, value-added, jobs, and wages, is the subject of investigation. The FC sector is dealt with separately as the FC-manufacturing (FC-M) sector and the FC-equipping and operating (FC-E&O) sector. The 2019 IO table, 34-sector classification, demand-driven model of the IO approach, and exogenization of the FC sector are used. The results show that each unit of investment or production in the FC-M and FC-E&O sectors triggers 2.328 and 1.793 units of production, 0.785 and 0.967 units of value-added, and 0.346 and 0.575 units of wages, for each sector, respectively, across the economy. KRW 1 billion of production or investment in the two sectors creates approximately 7.7 and 3.8 jobs, respectively. These figures can be useful for exploring the economic effects of FC deployment in the future on the South Korean economy.

Assessing the Nationwide Benefits of Vehicle–Grid Integration during Distribution Network Planning and Power System Dispatching

The diffusion of electric vehicles is fundamental for transport sector decarbonization. However, a major concern about electric vehicles is their compatibility with power grids. Adopting a whole-power-system approach, this work presents a comprehensive analysis of the impacts and benefits of electric vehicles’ diffusion on a national power system, i.e., Italy. Demand and flexibility profiles are estimated with a detailed review of the literature on the topic, allowing us to put forward reliable charging profiles and the resulting flexibility, compatible with the Italian regulatory framework. Distribution network planning and power system dispatching are handled with dedicated models, while the uncertainty associated with EV charging behavior is managed with a Monte Carlo approach. The novelty of this study is considering a nationwide context, considering both transmission and distribution systems, and proposing a set of policies suitable for enabling flexibility provision. The results show that the power and energy demand created by the spread of EVs will have localized impacts on power and voltage limits of the distribution network, while the consequences for transmission grids and dispatching will be negligible. In 2030 scenarios, smart charging reduces grid elements’ violations (−23%, −100%), dispatching costs (−43%), and RES curtailment (−50%).

Analysis of multi-objective cooperative optimization strategy for residential load under extreme weather

In recent years, the problem of seasonal power supply shortages in extreme weather has frequently occurred across China, which has brought great inconvenience to people’s production and life. At the same time, with the advancement of the energy revolution, the proportion of electric energy in the terminal energy is increasing, which also poses a severe challenge to China’s energy security. Our research, by constructing a residential electricity consumption model and conducting multiple electricity price response experiments, has collected data that assesses various factors involved in user responses. It has also explored and inferred the impact of these factors on user-side responses. This study introduces new research directions aimed at alleviating electricity supply-demand imbalances during different periods, contributing to the optimization and enhancement of the national power system.

Risk analysis of critical infrastructure with the MOSAR method

The smooth running of the electric energy system is crucial, especially given the current geopolitical environment. To achieve this goal, it is essential to establish a solid infrastructure that is both accessible and safe. We protect consumer reputation and trust, reduce financial losses, and lessen unfavourable effects on employees and business owners by maintaining continuous functioning. This study has discovered several important concerns using the Method Organised Systematic Analysis of Risk (MOSAR). These include the possibility of cyberattacks, the availability of information and technology systems, the loss of critical individuals, and network problems. To address these risks, it is necessary to deliver electrical energy on time and at a high standard, to be responsive to client requests, and to follow best practices, technical standards, and personal and environmental protection measures. The findings of this study make valuable contributions to risk assessment efforts, allowing us to identify potential threats to the security and reliability of national power systems. Overall, it is essential to maintain a robust and resilient energy infrastructure to ensure uninterrupted operation and mitigate risks effectively.

Managing BEV Charge to Obtain a Positive Impact on a National Power System

This paper’s research question is to evaluate the potential impact of large numbers of battery electric vehicles (BEVs) on the future electric grid, and whether the flexibility of BEV charging can induce enough system benefits to remunerate BEV users for the change in their recharging pattern. The considered scenario refers to the Italian situation and what might occur through the year 2040, where a share of BEV stock of 40% can be foreseen, as well as significant increases in PV and wind generation. Although this study is focused on Italy, its results are applicable, with minor differences, to several EU countries. This paper first shows that the future impact of increasing penetration of BEVs appears to be compatible with the expected growth of generation from renewable energy sources (RES) and the corresponding reduction in fossil fuel-based generation. It also gives an estimate of the CO2 emission reduction resulting from these changes, considering an unmanaged BEV charge profile and two different managed profiles that shift the car’s charging period to hours of the day when they have no negative impact on the grid and maximize the utilization of RES. Finally, it shows an evaluation of the economic benefits of displacing private car charging ranging from 4 to 10 cEUR/kWh, which could be used as tariff incentives to stimulate this displacing in recharging time.

Developing a new flexibility-oriented model for generation expansion planning studies of renewable-based energy systems

This paper presents a flexibility-oriented generation expansion planning (GEP) model with the goal of increasing renewable energy penetration. The model incorporates GEP and unit commitment while considering improved reserve requirements. Utilizing GEP and unit commitment results in considering short-term operational constraints. Furthermore, given the increase in renewable portfolio standards (RPS) and the need for accurate reserve requirements determination, it is essential to consider improved reserve requirements in the proposed model. Moreover, this model utilizes a metric that measures power system flexibility deficiency and leads to flexible power system expansion by integrating it into the objective function. The flexibility-oriented GEP model is developed using mixed-integer linear programming and applied to a scaled-sized case study representing the national power system of Iran with a twenty-year planning horizon. The results show that neglecting improved reserve requirements leads to plans short on flexibility, and considering these requirements substantially declines the upward flexibility violation costs by 68% under the base scenario and 87% under increasing non-hydro RPS scenario. Furthermore, using the flexibility metric coupled with improved reserve requirements changes the optimal path for power system expansion and reduces the risk of flexibility deficiency. Also, increasing RPS by 35% would strongly depend on developing fast-response dispatchable generation units in the years before renewable energy resources expansion; however it doesn’t impose a significant extra cost of planning and the total cost will increase just by 9.43%.

Optimal Configuration of Wind-PV and Energy Storage in Large Clean Energy Bases

The installed capacity of energy storage in China has increased dramatically due to the national power system reform and the integration of large scale renewable energy with other sources. To support the construction of large-scale energy bases and optimizes the performance of thermal power plants, the research on the corporation mode between energy storage and thermal energy, including the optimization of energy-storage capacity and its operation in large-scale clean energy bases. In this paper, a large-scale clean energy base system is modeled with EBSILON and a capacity calculation method is established by minimizing the investment cost and energy storage capacity of the power system and constraints such as power balance, SOC, and power fluctuations. The research proposed a method of using coupled system of thermal energy storage systems primarily based on molten salt thermal storage and thermal power generation for rough modulation and using battery energy storage system for fine modulation tasks. Example of fine modulation includes frequency modulation and heating demand of the district, which significantly reduces the energy storage investment by more than 95%. A case study of a 10 MW clean energy base is conducted. The result shows that the overall pre-tax internal rate of return of the base project is 8%, which has good economic benefits.

Generation Capacity of National Power System in View of Commodity Crisis and War in Ukraine in 2022: Diagnosis, Risk Assessment and Recommendations

Generation Capacity of National Power System in View of Commodity Crisis and War in Ukraine in 2022: Diagnosis, Risk Assessment and Recommendations

Measurement and Promotion Strategy of China’s Power System Regulation Capacity

Power system regulation capacity is the key factor affecting the development and consumption of renewable energy. Based on China’s policy to promote the consumption of renewable energy, this paper constructs an evaluation index system of power system regulation capability covering four dimensions: the supply side, grid side, load side, and support system. The entropy method is used to measure the power system regulation capability of 30 provinces during the 13th Five-Year Plan period. The results showed: (1) The national average power system regulation capacity index is 0.18, and only less than one-third of provinces scored higher than the average. (2) The contribution of each dimension is significantly different, and the supply side regulation capability was the highest (0.315). The regulation capability of the eastern region is stronger than that of the central region and the western region. From the perspective of subdivided fields, this study focuses on exploring five areas of power system regulation capacity construction, including electric vehicle energy storage, thermal power flexibility, regional power grid regulation, electric vehicle market, and grid construction, to tap greater development potential.

Assessing the technical and economic potential of wind and solar energy in China—A provincial-scale analysis

An accurate assessment of wind and solar resources is important for China's future transition to clean energy and the achievement of its carbon-neutrality goals. Based on climate data, geographical information, and the latest technical and economic information, this work estimates the total technical and economic potential of wind and solar power in China and their distribution by province. The main conclusions drawn by analyzing the spatial distribution and temporal evolution of the potential of wind and solar energy are as follows. (1) Both wind and solar energy have sufficient technical potential to support China's vision of carbon neutrality by 2060. (2) The potential is unevenly distributed spatially and is more concentrated in western and northern China, away from demand centers, with Xinjiang and Inner Mongolia accounting for >76% of the total technical potential of onshore wind and solar energy. The offshore wind potential is fairly equally distributed in coastal provinces. (3) In the near-to-medium term (5–10 years), fully utilized local wind and solar resources could help to meet the requirements of the non-hydro Renewable Portfolio Standard (RPS), and could significantly ease the urgency of building long-distance cross-province power transmission lines. For provinces with below-average RPS targets, the suggested non-hydro RPS targets could be further enhanced. (4) In the long term, the construction of adequate west-east and south-north transmission lines will remain essential to the construction of a national carbon-neutral power system.

High penetration of electric autorickshaw on national power system and barriers against the adoption of solar energy: A case study in Bangladesh

Peak hours' electricity demand is linearly related to carbon emission in fossil fuel-dominated power generation systems like in Bangladesh. Electric autorickshaws are becoming a burden for the national power system as their charging time coincides with the national peak hours. Solar electrification of the light-duty transportation sector is the focus of this work. This study identifies the uncontrolled growth of electric autorickshaws and their power consumption time as an alarming load for the national power system. To analyze the utilization of solar potential to reduce peak hours’ demand and identify the barriers underpinning the implication of solar potential in the autorickshaw sector are also the aim of this study. The results show that approximately 4660 MWh of electricity is consumed by autorickshaws in Bangladesh per day instead of the potentialities of approximately 23,000 MWh of solar energy generation capabilities per month in this sector. Cabalistic and plausible reasons behind not implication of solar potential in the autorickshaw sector are also analyzed. This study might be helpful for the related authorities in reducing peak demand and also solving the barriers responsible for not utilizing the solar potential.

Modeling cross-seasonal fuel savings from load shifting in the Saudi industrial sector and interlinkages to export revenues

We use a national Saudi power system dispatch optimization model to assess the implications of load shifting from the industrial sector. This model quantifies the fuel offtake, emission, and cost implications of shifting industrial loads from peak summer to off-peak winter months with industrial electricity tariffs and production levels unchanged. Then, the power sector results are used to assess macro implications –in the form export revenues. Our analysis shows that load shifting can save between $7.9 million and $17.7 million per year at the prevailing administered fuel prices and could reduce carbon dioxide emissions by up to 584 thousand tons. Furthermore, the total cost savings range from $127.2 million to $239.4 million per year when the opportunity costs of saved fuel (mostly crude oil) are considered. These potential savings represent 8.1% of the annual fuel costs of the system. Furthermore, we recommend shifting at least 15% of total industrial load to increase fuel savings if natural gas prices are reformed. We conclude by discussing potential policy enablers and barriers to adopting load shifting in Saudi Arabia.

Integration of high levels of electrolytic hydrogen production: Impact on power systems planning

The increasing interest in electrolytic hydrogen production using renewable electricity sources will require to adapt power systems to new electrical loads for hydrogen production and supply chains. Such high loads would impact the long-term planning and operation of power systems, as they need to balance the variability of renewable generation sources with electricity demand. This stresses the importance of characterizing the impact of incorporating hydrogen supply chains into power systems and planning accordingly. This study proposes a methodological framework to assess the integration and development of a national power system with electrolytic hydrogen production and supply chain. The framework is based on the well-known optimization tool for energy systems planning, Open Source Energy Modeling System (OSeMOSYS). For a detailed representation, a module was developed where demand side technologies – such as those associated to hydrogen supply chains – can provide operating reserves. As a case study, the integration of the Chilean power system with a hydrogen supply chain for exporting hydrogen between 2018 and 2050 was modeled. Among other findings, results indicate that an on-grid hydrogen supply chain would be more cost-effective than an off-grid one. However, the new electrical loads originated from such hydrogen supply chain would require additional generation capacity — primarily photovoltaic. Other generation capacities such as concentrated solar power, wind, and storage would experience significant variations in their investment requirements, compared to the off-grid hydrogen supply chain scenario. The study revealed that the coordinated operation of electrolyzers is crucial to the operational flexibility of the new electrical system.

Energy Productivity Potential of Offshore Wind in Poland and Cooperation with Onshore Wind Farm

Wind power is the leader in electricity production among the standing RES technologies, both in Poland and in Europe/World. In Poland, so far there are only onshore wind turbines. Their dynamic increase in installed capacity has been observed, especially between 2011 and 2017. This study analyzed the impact of offshore wind energy on the ability of the Polish power system to meet power demands. For this purpose, methods of statistical analysis (of existing onshore and planned offshore technologies) for the determination of wind turbine productivity based on wind speed components data from the ERA5 service were used. For onshore wind turbines, the value of the capacity factor CF(P) in Poland was 25.5% in 2021 and 30.1% in 2022. As a result of the simulation, it was calculated that for the planned offshore wind farms, the capacity factor CF(B) would be 55.6% under 2022 wind speed conditions. The 2022 peak load demands in the Polish system were also analyzed. The quantitative impact of installing 6 GW of offshore wind turbine capacity on the national power system was also identified.

The Use of a Regulating Transformer for Shaping Power Flow in the Power System

The current situation in world energy requires a new approach to the control of the power flow in power systems. On the one hand, regulations within the EU require the transition to renewable energy. On the other hand, there are no conventional sources available. Thus, there is a need to use known control tools in non-standard applications. One such example is the use of a regulating transformer inside the power grid to use it to shape the power flow in the system. This article presents a proposal of an algorithm for determining new locations for regulating transformers from the point of view of active power control. By analyzing the parameters of the power grid, it is possible to determine which branch of the grid is the most suitable for installing a regulating transformer in it. The use of a regulating transformer inside the grid improves the transmission capabilities of the national power system.

Modelling a pumped storage power plant on the example of the Porąbka Żar power plant

This article presents the idea and mathematical model of a pumped storage power plant. PSPS Porąbka Żar was selected as the real object for modelling. Due to the specificity of the operation of an intervention-regulatory and scheduled nature related to the coverage of power demand in the power system, the possibility of different modes of operation was taken into account in the model. Porąbka-Żar power plant is a pearl of hydro-engineering on the global stage. It is the first underground and the second largest pumped storage power plant in Poland. It is located in Międzybrodzie Bialskie, in the Silesian province. The short distance between the upper reservoir of the power station, located on Mt. Żar, and the lower reservoir of the międzybrodzkie lake, the high average head of the power station of 432 m above sea level, create great opportunities for accessibility and interference in the operation of the power station. It is equipped with four reversible Francis turbine sets, which operate simultaneously with a total capacity of 500 MW in the generator mode and 542 MW in the pumping mode. Due to its high potential and short turn-on and turn-off times of the turbine sets, it plays an important role in the national power system. The mathematical model was made in Matlab - Simulink software. An important role in the control process of the facility is played by the forecast of both power demand and contingencies. The forecasting model is equipped with elements of artificial intelligence. In addition, the article shows the possibility of supplementing an operating power plant with hybrid elements. The analysis is supported by commentary and a number of charts

On the Importance of Self owned Power Plants Participating in the Adjustment of Supply and Demand of Power Network under the Reform of Power System

Centralized power generation by self owned power plants of high energy consumption enterprises will lead to insufficient peak shaving capacity of the power grid. Once the self owned power plants have operational problems, they will easily lead to large-scale blackouts, which will have a great impact on power supply reliability. The national electric power system reform opinion points out that the regulation focus of ensuring the balance of power supply and demand in the power grid should be shifted from the generation side to the load side, and the potential advantages of self owned power plants that combine power generation resources with large loads can be utilized. Self owned power plants participate in the equal management and fair competition of public power plants, can better play its role while improving the supervision of self owned power plants, which is conducive to maintaining the order of the power market and improving the stability of the implementation of power reform.