Table of Contents
1 INTRODUCING VOLATILITY AND ENERGY PRICES
1.1 Volatility
Recent changes in the global energy sector have dramatically impacted the production and consumption of energy throughout the world. It is well known that the price of energy is quite volatile, reflecting the changes made by market participants in response to new information from physical energy markets and/or markets for financial derivatives relating to energy. Price volatility is a sign of the market’s degree of risk or uncertainty.
Energy investment assets include BESSs and equipment for renewable energy generation, among others. Risks associated with these assets are mainly related to how well electricity market price spikes are managed. Market price spikes are defined as price jumps of extreme size due to sudden imbalances in supply and demand. The situation is similar to power network generators, which generate the most revenue during market price spikes.
Volatility is assessed by the day-to-day difference in the price of energy. The degree of variation, not the level of prices, defines a volatile market. Few costs impact a company’s bottom line more directly than its energy spend. Prices of basic energy (natural gas, electricity, heating oil) are generally more volatile than prices of other commodities.
A large body of literature has analysed the volatility patterns of energy prices, with the majority of studies focusing on the average market behaviour over a long sample period. Several recent studies have examined how economic policy uncertainties affect various aspects of the energy market, analysing the linkage between oil market shocks, stock market returns, and monetary policy uncertainty [1]. They found that shocks to the oil market due to global aggregate demand not only increase real oil prices but also decrease the level of economic policy uncertainty.
Many analysts caution that the prices of non-renewable energies may experience a next bout of volatility due to economic policy uncertainties, particularly the lack of clarity over trade policies and unclear international efforts toward greenhouse gas mitigation. With the return of price volatility, natural gas trading is experiencing a revival in the United States. At the same time, European market turbulence could keep gas demand and exports high for years [2]. Due to extreme weather conditions and the European Union’s hunt for alternatives to Russian gas supplies, sharp natural gas price swings that can result in enormous profits for traders have reemerged. Prices at the primary gas trading centre in the United States have increased by 64% this year, reaching their highest level since 2008.
1.2 The Current Scenario
In the long term, the increase in the case of energy prices has been extremely high [3], with prices in the period 2005–2016 being around eight times higher than those in the period 1960–1974. This remarkable price hike was driven by all three energy commodities (oil, coal, and natural gas), with the upsurges in crude oil (835 per cent) and natural gas (485 per cent) being particularly pronounced.
Energy prices increased nearly five-fold from 1998 to the pre-crisis peak in 2008, and, following a drop in prices in 2009-2010 in response to the global financial crisis, they climbed further throughout 2011 and 2012. Since then, however, energy prices have declined rapidly, and 2015 stood at barely half the price recorded in 2012.
Figure 1. IAEA Director-General during his press briefing on the situation at the Zaporizhzhia Nuclear Power Plant in Ukraine. Source: https://www.flickr.com/photos/iaea_imagebank/51917564434/
Lately, energy costs around the world are at record highs as a power crisis hits Europe and Asia — and the International Energy Agency noticed that volatility is here to stay. In its annual report [4], the agency said the world is underinvesting now for future energy supply, making the transition to net-zero emissions risky. “There is a looming prospect of more turbulence for global energy markets,” Fatih Birol, IEA’s executive director, said in a statement. “We are not spending and devoting enough to meet… future energy needs, and the uncertainties are setting the stage for a volatile period ahead.” The report pointed to policy and demand uncertainties, among other things, as reasons behind the current underinvestment.
Commodity markets are under tremendous pressure, with some commodity prices reaching all-time highs in nominal terms, according to the World Bank’s Prospects Group. Energy prices are expected to rise more than 50 per cent in 2022 before easing in 2023 and 2024. This will have lasting knock-on effects. The sharp rise in input prices, such as energy and fertilisers, could lead to a reduction in food production, particularly in developing economies.
Trade patterns are becoming more expensive as a result of the conflict in Ukraine, which could contribute to inflation that lasts longer. It is anticipated to divert energy commerce significantly. For instance, some nations are currently looking for coal sources from more distant regions. Simultaneously, certain significant coal importers may increase their shipments from Russia while decreasing their purchases from other influential exporters. Studies indicate that because this detour includes longer transportation distances and coal is large and expensive to transport, it is likely to be more expensive. Natural gas and oil are also being diverted in a similar way.
Moreover, electrical energy trading is rapidly changing with the increase in distributed energy resource (DER) connections. Traditional energy consumers are becoming prosumers that both consume and generate energy. In essence, the electricity generation of DERs is challenging to predict because of the stochastic nature of these resources. If, for instance, energy is stored in an energy storage system (ESS) and exported back to the grid or other energy consumers, the optimal control can achieve economic benefits. The volatility of the electricity market price and uncertain cycling load mean that finding an optimal solution for a customer ESS is challenging. Market price involves a nonlinear stochastic process that consists of the base price and spikes. Therefore, price characterisation is a demanding but vital task, as managing market price spikes is critical in mitigating the risks of investing in ESSs for residential customers and other energy-related infrastructure.
2 ASPECTS OF ENERGY COMMERCE
2.1 Energy Price Components
While the price of energy is the amount of money for which an amount of energy is sold at the retail or wholesale market, retail energy prices consist of three components: energy, network and taxes/levies.
Energy tariff items are driven by wholesale prices but also by market conditions such as market liberalisation, deregulation, and the degree of competition, . At the wholesale level, the generation mix, fuel and CO2 costs, or international commodity prices as well as trade features (historical contracts, organisational, infrastructure), the degree of competition and demand determine wholesale prices. Furthermore, the market power of consumers, i.e. demand-side aspects, also impacts costs. This complex interdependency is depicted in Figure 2 for the European context.
Figure 2. Drives of electricity and gas wholesale and retail market prices. Source: https://ec.europa.eu/energy/sites/ener/files/documents/annex2_ecofys2016.pdf
Since the start of the industrial revolution in the mid-eighteenth century, human beings’ demand for energy has been growing even daily. Accurately predicting the energy price contributes to making better decisions for policymakers, generators, utilities, and customers. For instance, a research team [5] presented a strategy to maximise the profit of wind power stations based on wind power and market price forecasting. Others [6] pointed out that the prices of natural gas, carbon, and so forth would partly be a driver of the changes in wind turbine prices. As a result, the precise prediction of associated data in the energy market is a promising research project in the twenty-first century.
Electricity
The three components involved in transporting electricity from the generation plant to your business are generation (the production of electricity), transmission (the high-voltage towers and lines), and distribution (the poles and wires which deliver electricity to your business or meter). The generation piece, or electric commodity, is the deregulated portion you can purchase independently. This charge includes the cost of generating power and delivering it to your meter or locational zone, depending on your local distribution company.
Natural Gas
For natural gas, there are also three components that make up the total price. The supply cost is the actual commodity of natural gas brought from the supply source, usually in the Gulf of Mexico. The transportation, or basis cost, is the charge for transporting the gas through the interstate high-pressure transmission pipelines to the local city gate or town border station. The regional distribution charges carry the gas from the local city gate and deliver it to your meter.
For both gas and electricity, when you buy your commodity from a third-party supplier, you are still responsible for the local transportation charges of the distribution system, poles and wires for the electric company, and delivering the gas from the local city gate to your actual meter. These charges will be included in the bill from your local distribution company, and you would be paying them even if you were not working with a third-party supplier. Account representatives from your local distribution company will discuss their rates with you so you will understand your “price to compare” when you explore competitive offerings.
2.2 Macroeconomic Uncertainty and Oil Price Volatility
Oil price volatility that tracks changes in oil price has continuously been considered a major but complex issue. Indeed, oil is not only a major component in production but is also a key driver of consumer purchasing power. Oil price volatility is not constant over time. After being historically low for several years, oil price volatility spiked in the period surrounding the financial crisis and the European sovereign debt crisis. Also, more recently, limited changes in oil demand and supply due to COVID-19 pandemics caused oil prices to drop considerably, while geopolitical concerns and trade embargos caused oil and gas prices to soar [7]
There are two general explanations for why oil price volatility changes over time. First, periods of elevated oil price volatility can simply be caused by large oil shocks. In the 1970s, for example, large shocks to oil supply explained most of the high oil price volatility observed during that period. The second explanation for higher oil price volatility is that oil prices can become more sensitive to oil demand and supply variations. For the exact change in the demand or supply of oil, the reaction of the oil price is stronger. This occurs when the price elasticity of oil demand and supply is lower, i.e. when the sensitivity of oil demand and supply to oil price changes is reduced. For example, if oil demand reacts less to an oil supply shock, the price response is magnified as there is a minor adjustment through the quantity side. As such, lower price elasticity of oil demand increases oil price volatility.
There are several reasons why uncertainty might lead to higher oil price volatility. One possible and widely documented channel is that tension changes the decision-making behaviour of economic agents. When uncertainty is high and shocks hit the economy, the adjustment in quantities is constrained due to a delay in the production or consumption decision, reinforcing the adjustment through the price side. This channel is shown to be operative for the oil market as well [8]. Another possibility, although more speculative, is that uncertainty increases the use of hedging instruments which might make demand and supply less sensitive to oil price changes.
COVID-19 led to a sharp decline in oil demand, which was already marked by a high level of uncertainty, especially in the US, Japan and the EU. Indeed, the oil market remains extremely volatile. Nevertheless, oil demand appears to have reached its peak, with the major economies already showing signs of a need to diversify. Further, uncertainty regarding both the recovery from COVID-19 and the war in Ukraine remains high, a situation that could lead to increased inertia with respect to the demand shock. Accordingly, the current situation is unprecedented for the oil industry. In addition to the usual context of the geopolitical environment and increased political tension, as well as the lingering vulnerability of commodity markets since the recent global financial crisis, the coronavirus pandemic has led to a major new challenge for the oil industry, taken by surprise by the public health crisis that has affected both supply and demand.
3.3 Energy Procurement Guide
Energy procurement is the strategic process of sourcing our energy (electricity and fuel) needs from a third-party retail supplier or local distribution company (LDC or utilities).
Different Energy Contracts
Fixed Contract: With a fully fixed energy pricing plan, the customer is committed to a predetermined price for the length of the contract. Throughout the term, the cost per kilowatt-hour remains constant regardless of market variations (subject to adjustments due to changes in law, new legislation, or passed through regulatory components). Customers often select a fixed pricing plan in order to reduce the monthly regional price risk and give budget stability (e.g. due to weather, pipeline constraints, generation retirements, etc.). It is especially advantageous in a market where price increases are anticipated to continue.
Indexed Electricity Billing: A totally fixed contract is on one end of the spectrum, while a fully indexed electricity pricing plan is on the other. The customer receives indexed pricing components at market settlement prices even though all features are locked at a fixed rate and set price. Index pricing typically performs better than fixed pricing (on a weighted $/kWh basis) depending on the timing and length, but at the risk of exceeding budgets because of pricing volatility.
Block and Index: The “block and index” method, which combines components of fixed pricing with index pricing, lies in the middle of the spectrum. Fixed price “blocks” (also known as hedges) are placed strategically throughout the contract term to protect against (usually) volatile time periods (e.g., peak hours in the summer in warm regions). Blocks of various sizes can be organised for peak, off-peak, or 24-hour time periods.
What Is an Energy Procurement Service?
Energy procurement is the process of obtaining energy from suppliers or utilities for commercial usage, and procurement services are those that support commercial users in this endeavour. Energy procurement service providers create programs for companies aiming to cut costs and improve their energy efficiency using their industry expertise and understanding of best practices.
Procurement service providers often use a few typical strategies when interacting with clients. These procedures include anything from doing internal and market analyses to developing a real connection between the client and the energy seller.
Optimal pricing and risk mitigation
Typically, energy procurement consulting services can identify energy buying strategies across every facility in an organisation. By comparing energy rates and tariffs, they can ensure the client is not over-paying for energy and that it finds other buying opportunities in real-time. In addition, one can mitigate risk with energy forecasting tools that assess where the market is headed and recommend the best course of action.
Advanced energy procurement consulting services rely on sophisticated analytics and monitoring by a team of professionals to build a comprehensive approach that looks at supply-side and demand-side opportunities.
3 MARKET REGULATIONS
3.1 Participating in the De-regulated Energy Marketplace
Participating in the energy marketplace can be advantageous for many reasons. Businesses can purchase energy and manage their consumption to achieve greater efficiency and effectiveness in their operations. Controlling operating costs can affect profitability, and reducing energy supply costs positively affects profitability.
With a better grasp of energy use and how energy is priced, businesses can be more competitive in today’s market. Managers who understand their commodity consumption for both gas and electricity, and know how to manage and purchase these resources effectively, will ultimately reduce costs and increase profits. Before trading a commodity, we need to understand how much energy we use and when we use it, remembering that the cheapest kilowatt is the one we don’t buy.
Plan to obtain 12 months of usage data from your local distribution company for electricity. These data should include on-peak and off-peak usage. If your usage is large enough for a time-of-use meter, you will want to request the “interval” load data which will reflect your usage for each 15- or 30-minute period. These are the data that the majority of energy marketers use when pricing the commodity to meet your particular electric requirements.
For gas usage, plan to obtain 24 months of history. With variations in winter weather, usage can differ significantly, and your profile from more than one season presents a more accurate non-weather-related picture.
Figure 3. Virtual representation of energy generation and distribution infrastructure. Source: https://www.overit.it/es/sectores/
To evaluate third-party suppliers, you will need to obtain a list of the eligible, licensed electric or gas suppliers or aggregators in your service territory from your local distribution company or your state public utility control website. These entities will be a good reference point as you evaluate potential suppliers. You will want to determine if the potential supplier has the necessary assets to serve your business.
Evaluate a third-party supplier on pricing options and determine which options best suit your needs, such as fixed vs. float pricing and contracts. Be prepared to evaluate offers from various electric and gas suppliers, which will be presented as a part of their contract. Components of supplier contracts for electricity can vary and require careful scrutiny. Common elements include energy, capacity, ancillary charges, and locational costs. Suppliers may treat these components differently and refer to them in different terms.
Also, you will want to know if the contract restricts how much electricity or gas you can use and when you may use it. Are you planning any increasing or decreasing plant additions or shift changes that may impact your future usage? Since contracts are based on historical usage, there may be penalties for use outside of a 10 per cent range plus or minus your monthly usage for the same period in the previous year (this variation is often called “swing”) [9].
You may also want to consider the environmental impact of the generation source you could be selecting. Specific calls for electricity, each electric generation supplier should provide information explaining the ecological characteristics of the electric portfolio they sell. You may choose a supplier that integrates a minimum percentage of “green” power.
3.2 The Texas Case
The Texas restructuring plan and market design
Texas lawmakers opened up the state’s power market almost twenty years ago. For private enterprises to go after clients and compete for business in a free-market bonanza that would allegedly drive down costs for consumers across the state, long-standing regulations limiting who may sell energy to whom and how much they could charge for it was abandoned.
Texas’s interconnected electrical power grid distributes electricity over a vast geographic area from supply generation to end-use users. The Western Interconnection (which serves the western states aside from Alaska and Hawaii), the Eastern Interconnection (which serves the eastern states) and the Texas Interconnection (which serves only Texas) are the three main wide-area synchronous electric power grids in the United States. It’s interesting to note that Texas is distinct from the rest of the nation in having its own electrical grid. As a result, it is a great idea to research and contrast Texas’s deregulated and privatised electric power market with that of the rest of the country.
Under the plan, which the Texas Legislature passed in May 1999, customers of most of the state’s investor-owned utilities were permitted to choose among various REPs beginning in January of 2002. Pilot customer choice programs were initially scheduled to start on June 1, 2001, although this target date slipped to July 31, 2001, due to technical delays at ERCOT. Rural electric cooperatives and municipal utility systems were permitted latitude to either participate in the plan (opt-in) or decline to participate. However, changes in the wholesale market would affect them regardless of their decision regarding retail choices.
ERCOT was assigned responsibility to serve as an independent system operator (ISO) for most areas of Texas, with a mandate to preserve reliability, foster the final design of the market, coordinate the scheduling of wholesale transactions among market participants, coordinate the switching of customers among the REPs, facilitate the transfer of meter reads from transmission and distribution services providers (TDSPs) to the appropriate REPs, and perform financial settlements.
Figure 4. Investor-owned utility service areas in Texas. Source: https://doi.org/10.1016/S0301-4215(03)00193-9
So, did it work?
According to a recent report [10], Texans who take the time to compare their options might find reasonable offers in the state’s deregulated power market. According to the most recent data available, however, the typical Texas consumer (about 85% of the state) continues to pay significantly more for power than those served by monopoly companies in places like Austin and San Antonio.
Texas residents are increasingly finding individual offers on the deregulated market that are less expensive than what regulated utilities offer, despite the fact that price data for some years was not completely available. In 2012 and 2013, the analysis showed that Texans in deregulated areas for the first time paid lower electric bills on average than most Americans. Nationally, Texas was the 18th cheapest state to power homes between 2002 and 2015. Residents in just nine states saw lower prices than Texans in regulated areas during that period. Twenty-six states averaged cheaper energy fees than Texans in the competitive market.
The Texas Coalition for Affordable Power and other consumer groups suggest that continued inefficiencies, customer confusion and relatively high prices from legacy electricity providers could be to blame. Since competitive providers locked into expensive gas contracts and took years to recover, a natural gas price spike early after deregulation, followed by a steep decline, may have also contributed to the trend. The coalition acknowledges that element but asserts that it cannot explain the pattern on its own.
Reports also showed that the steadiest increase in most Texas utility bills is not the cost of electricity but the fees charged to deliver it. Customers can choose whom to buy power from, but monopoly power transmission companies still have to deliver it to homes and businesses. Texas rapidly grew during the 2000-2020 time frame, embarking on many massive transmission projects, including building new power lines to carry renewable energy and installing millions of “smart meters” to track energy use in hopes of boosting efficiency. “All of that has to be paid for,” executives at the state’s Association of Electric Companies said.
4 MANAGEMENT AND PROCUREMENT TRENDS
4.1 Control Strategies for Battery Energy Storage System
A proper control strategy is required to evaluate the revenue and net income to take advantage of energy storage investment opportunities. A control strategy for residential customers requires that storage volumes, net load characteristics, and market price [11] are all considered and that optimal decisions are made.
In the actual volatile context, model predictive control (MPC) must address the following challenges. First, the control strategy must be optimal. The conventional MPC does not guarantee optimality. Furthermore, the daily repetitive nature of the net load causes the MPC’s receding one-day-ahead prediction horizon to have different cycling load levels. Consequently, the equality terminal constraint becomes too challenging to incorporate into the optimisation process. The final challenge is modelling the probabilistic characterisation of energy prices and integrating them into the MPC.
To achieve the optimal economic benefits for customers in a volatile electricity market with a daily cycling load, specialists have proposed a control strategy based on a modified version of a conventional MPC. A new cost function models a probabilistic relation between flow, the net load, and the electricity market.
Figure 5. Diagram of a household with a BESS. Source: https://ieeexplore.ieee.org/document/9465775
Subsystems that comprise a BESS system include a control unit, communication link, and smart meter. The control unit regulates the energy stored in the batteries driven by a variable local demand and energy price. The communication link is assumed to provide real-time information about energy price changes to the control unit. A smart meter measures the energy flow between the power grid and a household equipped with a BESS. A simplified block of a household with a BESS is presented in Figure 5, where F (t ) is the power exchanged with the grid and measured by the smart meter; L(t) is the net load power defined as the difference between local demand and local generation; u(t) is the battery power.
4.2 Impact of Blockchain and Internet of Things on Public Procurement
Public procurement is one of the top fields calling for national and international interest. The large publicly procured volumes, the share of contracts’ value usually lost to corruption, the major environmental and general societal impact of procurement, and the fact that public procurement is a key component in the global economy all of that point to a significant interest in restructuring and improving this field of activity. The different trends encountered reveal major challenges in this field as well as attempts at transforming public procurement into smart and sustainable procurement [12].
Different urban infrastructure systems may incorporate innovative digital technologies assisted by a cognitive IoT that would supply real-time sustainable data (in regard to energy, pollution, the carbon footprint and climate change) that are essential in the circular economy. The digitalisation of public procurement may support daily business tasks, facilitate complex decision-making and lead to the development of those activities that are strategic by nature. The technologies currently used in procurement focus on specific processes, such as e-sourcing, contract management and e-procuring.
The use of emerging technologies allows for the identification of the carbon emissions for each company, which spotlights aspects such as pollution and the exhaustion of the energy sources; defining incentives for the organisations that are more environmentally friendly; streamlining the transport activity and reducing greenhouse gas (GHG) emissions; lower waste volumes. Moreover, the blockchain and IoT combination may identify the necessary resources and their allocation algorithm to deliver economic competitiveness, efficient waste disposal and reduce energy consumption [13].
Although procurement corruption varies in severity from nation to nation, some similar reasons include poor record-keeping, a lack of public accountability, frequent and close connections between the private sector and government representatives, and centrally controlled procedures. These elements work together to generate a high-value, opaque, and complex process that is corruptible.
The World Economic Forum’s most recent paper, Exploring Blockchain Technology for Government Transparency: A Blockchain-Based Public Procurement System, examines blockchain technology’s potential for reducing public-sector corruption in general as well as its viability for public procurement.
Figure 6. Corruption and blockchain. Source: https://www.weforum.org/agenda/2020/06/governments-leverage-blockchain-public-procurement-corruption/
5 CONCLUSIONS
Increasingly, corporations strive to demonstrate environmental stewardship by turning to “green” products. They may be able to purchase a portion of their energy from renewable sources, which helps promote newer technologies and reduce greenhouse gas emissions. However, in the near-term, higher prices threaten to disrupt or delay the transition to cleaner forms of energy. Several countries have announced plans to increase the production of fossil fuels.
Participating in the energy marketplace can be beneficial for many reasons. Businesses can procure energy and manage their consumption to achieve greater efficiency in their operations. Reducing energy supply costs and general operating costs has a positive impact on profitability. Businesses can be more competitive in the current and future volatile markets with a better comprehension of energy use and how power is priced.
Managers who understand their commodity consumption for both gas and electricity, and know how to manage and purchase these resources effectively, will ultimately reduce costs and increase profits. To obtain the best price for energy commodities, they need to understand the futures market, pricing options, and how to get competitive bids. The electricity and natural gas markets are subject to a degree of volatility.
Many states are rolling back restrictions and allowing individuals and businesses to source energy from private retailers. These changes present an alternative to utility company-monopolised contracts — trading traditional gas, oil, and electricity models for deregulated, competitive, and transparent retail partnerships. Managed proactively, energy procurement with a retail vendor can bring businesses a list of advantages, including i) increased operational efficiency, ii) reduced energy costs, iii) improved operational sustainability, and iii) greater peace of mind in running a business.
Being well-informed is vital. Energy market conditions change rapidly. One should be able to depend on a competitive supplier for industry expertise, updates on market conditions, regulatory trends, and risk management methods.
We have reviewed how to evaluate potential suppliers so that risk is minimised and the energy supply is assured. We have also demonstrated that by understanding market dynamics, taking steps now to assess energy needs, and obtaining the best possible price, businesses will be able to sell and buy energy in the volatile marketplace.
6 REFERENCES
[1] Scarcioffolo, A. R., & Etienne, X. L. (2021). Regime-switching energy price volatility: The role of economic policy uncertainty. International Review of Economics & Finance, 76, 336-356.
[2] Price volatility and rising demand revive US natural gas trading | Reuters
[3] Foster-McGregor, Neil & Spinola, Danilo & Verspagen, Bart. (2018). On the development and impact of commodity prices and cycles. 10.13140/RG.2.2.31075.58403.
[4] Overview and key findings – World Energy Investment 2022 – Analysis – IEA
[5] Khalid M, Aguilera RP, Savkin AV, Agelidis VG. On maximising profit of windbattery supported power station based on wind power and energy price forecasting. Appl Energy 2017;211:764e73.
[6] Bolinger M, Wiser R. Understanding wind turbine price trends in the U.S. over the past decade. Energy Policy 2012;42(2):628e41.
[7] https://www.eia.gov/finance/
[8] Van Robays, I. (2016). Macroeconomic uncertainty and oil price volatility. Oxford Bulletin of Economics and Statistics, 78(5), 671-693.
[9] Coutz, P., & Geronimo, J. O. (2008). Participating in the De-regulated Energy Marketplace: Cutting Costs Without Losing Your Shirt. Strategic planning for energy and the environment, 28(2), 8-23.
[10] Deregulated Electricity a Mixed Bag for Consumers | The Texas Tribune
[11] Jovanović, D. P., Ledwich, G. F., & Walker, G. R. (2022). Model Predictive Control Strategy for Residential Battery Energy Storage System in Volatile Energy Market with Uncertain Daily Cycling Load. Journal of Modern Power Systems and Clean Energy.
[13] M. Mircea, M. Stoica and B. Ghilic-Micu, “Analysis of the Impact of Blockchain and Internet of Things (BIoT) on Public Procurement,” in IEEE Access, vol. 10, pp. 63353-63374, 2022, doi: 10.1109/ACCESS.2022.3182656.
