Preprint
Brief Report

Forecasting Hydropower with Innovation Diffusion Models: A Cross-Country Analysis

Altmetrics

Downloads

62

Views

20

Comments

0

A peer-reviewed article of this preprint also exists.

This version is not peer-reviewed

Submitted:

07 October 2024

Posted:

08 October 2024

You are already at the latest version

Alerts
Abstract
Hydroelectric power is one of the most essential renewable energy sources in the world. In addition to generating electricity, hydropower offers other benefits such as flood control, irrigation assistance, and clean drinking water. In this study, we examine the evolution of hydropower in the context of energy transition with a forecasting analysis. We analyze time series data of hydropower generation from 1965 to 2023 and apply Innovation Diffusion Models as well as other models such as Prophet and ARIMA for comparison. The models are evaluated for different geographical regions, namely the North, South, and Central American countries, the European countries, and the Middle East with Asian countries, to determine their effectiveness in predicting trends in hydropower generation. The models' accuracy is assessed using Mean Absolute Error (MAE), Root Mean Squared Error (RMSE), and Mean Absolute Percentage Error (MAPE). Through this analysis, we find that, on average, the GGM model outperforms the Prophet and ARIMA models, and is more accurate than the Bass Model. This analysis underscores the critical role of precise forecasting in energy planning and suggests further research to validate these results and explore other factors influencing the development of hydroelectric generation.
Keywords: 
Subject: Business, Economics and Management  -   Econometrics and Statistics

1. Introduction

The increase in the world population is directly related to an increase in energy consumption, especially electricity [1,20]. This increased demand for energy, if not met sustainably, can harm the environment, particularly due to air pollution and climate change effects [22] deriving from the burning of fossil fuels such as coal and natural gas [20]. However, fossil fuels, including coal, oil, and natural gas, still serve as primary energy sources worldwide [13]. To contrast this reliance on fossil fuels, interest in renewable energy sources has recently increased significantly worldwide [5]. Renewable energy includes sources that naturally regenerate, such as hydroelectric, solar, wind, and geothermal energy. These sources are far more sustainable and environmentally friendly compared to fossil fuels. With technological advancements, particularly with the initiation of the Fourth Industrial Revolution, the adoption of renewable energy sources is expected to soar. This shift is crucial for alleviating the effects of climate change, greenhouse gas emissions, and increasing energy costs [18].
Hydropower, one of the oldest and most well-researched renewable energy sources, has a history of nearly 150 years. Despite its longstanding presence, innovation in hydropower remains vibrant, with current efforts centered on enhancing plant flexibility via improvements in turbine design, operational strategies, and digitalization. These innovations are intended to help hydropower plants better address the needs of modern power systems, which encounter more variable energy demands and a growing share of intermittent renewable sources. Reservoir-type hydropower plants, in particular, are well-equipped to offer the necessary emissions-free flexibility for today’s power systems [17]. This critical renewable energy source leverages the power of rivers and reservoirs, playing an essential role in electricity supply, particularly in nations with limited resources [28]. Hydropower is an economical and environmentally friendly option for energy production, providing numerous additional benefits such as flood control, irrigation support, and clean drinking water, alongside electricity generation [24]. These characteristics make hydropower an appealing and deserving candidate for increased attention and investment [2]. This explains why hydroelectricity generation rose by nearly 70 TWh (close to 2%) in 2022, reaching 4300 TWh. In fact, hydropower remains the largest renewable electricity source, producing more than all other renewable technologies combined, and is expected to remain the world’s largest source of renewable electricity generation into the 2030s. Therefore, it will continue to play a critical role in decarbonizing the power system and improving system flexibility. It is also acknowledged that, without major policy changes, global hydropower expansion is expected to slow down this decade. The contraction results from slowdowns in the development of projects in China, Latin America, and Europe. However, increasing growth in Asia Pacific, Africa, and the Middle East partly offset these declines. Increasingly erratic rainfall due to climate change is also disrupting hydro production in many parts of the world. In the Net Zero Emissions by 2050 Scenario, hydropower maintains an average annual generation growth rate of nearly 4% from 2023 to 2030, aiming to supply approximately 5500 TWh of electricity per year. As stated in [17] in the last five years the average growth rate was less than one-third of what is required, signaling a need for significantly stronger efforts, especially to streamline permitting and ensure project sustainability. Hydropower plants should be recognized as a reliable backbone of the clean power systems of the future and supported accordingly.
Starting from these pieces of evidence, our study aims to analyze the role of hydroelectric data in countries’ energy transition using the approach of Innovation Diffusion Models [9]. The literature on the application of innovation diffusion models for energy growth processes has been developing significantly in recent years and our paper aims to contribute to this direction. We propose a cross-country analysis of hydropower generation, provide some forecasts based on Innovation Diffusion Models [9], and compare their performance with typical time series models such as ARIMA models [16] and Prophet model [29].
The rest of the paper is organized as follows: Section 2 offers a review of the existing literature, setting the stage by discussing previous research and developments relevant to hydropower. Section 3 outlines the data sources and methods employed in this study. Section 4 presents a detailed analysis and discussion of the results, interpreting the findings concerning current challenges and opportunities for hydropower. Finally, Section 5 provides concluding remarks, summarizing the key insights of the study and offering recommendations for future research and policy actions to enhance the role of hydropower in sustainable energy systems.

2. Background Literature

In the hydroelectric generation forecasting literature, various statistical, econometric, machine learning, and hybrid models have been widely used. These methods differ in methodology, complexity, and performance [15]. The most widely used methods for forecasting hydroelectric generation have been linear time series models such as ARIMA models and their different extensions [8]. For example, in a study using data from India, the authors used ARIMA models to model and forecast hydroelectric generation, which accounted for more than 60% of global renewable energy [19]. The study used various ARIMA models to analyze historical data from 1971-1972 to 2019-20. The researchers determined that the ARIMA(1,1,1) model with drift was suitable to forecast the energy demand of the country. In [25], ARIMA models were used with monthly data obtained from the Son La hydroelectric plant in Vietnam, covering the period from January 2015 to December 2019. Similarly, in [23], data from the official site of the Electricity Regulation and Control Agency (ARCONEL) were analyzed for the years 2000 to 2015, focusing on monthly reports on energy production from hydroelectric plants in Ecuador. The results indicated that the A R I M A ( 1 , 1 , 1 ) x ( 0 , 0 , 1 ) 12 model, which incorporated seasonality, best fits the time series data, allowing for forecasts of energy production for one to twelve months ahead. This model was trained using data from 2000 to 2014 and validated with data from January to December 2015, and its forecast for 2020 suggested an increase in monthly production, with actual values falling within the confidence intervals of the ARIMA model’s predictions with annual seasonality.
In [30], the authors introduced a new gray combination optimization model to forecast China’s hydropower generation, using data from 2000 to 2020. They split the data into a training set (2000 to 2015) and a test set (2016 to 2020). The TDGM (three-parameter discrete grey model) outperformed ARIMA and SVM (Support Vector Machines) [?], achieving a low Mean Relative Forecast Percentage Error (MRFPE). Forecast results indicated that China’s hydropower generation could reach 1687.738 billion kWh by 2025, reflecting a 24.5% increase from 2020. In [21], the authors presented a novel ensemble forecast model to predict medium to long-term wind and hydroelectric generation, using data from November 2010 to December 2020. The model involved three phases: Phase I combined ARIMA and Bi-LSTM predictions, Phase II incorporated forecasts for seasonal and off-season periods using the Deliberate Search Algorithm (DSA), and Phase III merged the predictions from both phases. The results showed that the Mean Absolute Error (MAE) for wind and hydropower ranged from 1.97% to 5.52% and 2.3% to 6.42%, respectively, while the Root Mean Square Error (RMSE) ranged from 2.7% to 7.8% and from 2.63% to 8.4%, for timeframes from one week to the next year.
In this paper, we propose to use the different approaches of Innovation Diffusion Models to describe and predict the growth of hydroelectric power. This choice relies on a well-established stream of literature that has employed diffusion models to study renewable energy sources, to understand the dynamics underlying energy transition by using both univariate (see for instance [10]) and bivariate models (see [4]). Recent reviews of this literature may be found for instance in [9], [3], [4], [27].
However, the analyses proposed in the literature have typically focused on renewable energy sources like wind and solar ([10]), whereas hydroelectricity has not been studied in much detail. Moreover, the studies using innovation diffusion models have tried to describe the patterns of growth of these energy technologies, without paying much attention to their forecasting ability compared to other models. In this paper, we try to fill this gap by focusing on hydropower data with a forecasting analysis.

3. Materials and Methods

In this section, we provide details of the data used in the analysis and the models that have been employed for forecasting. Specifically, we offer a description of the Bass, GGM, Prophet models, and ARIMA models.

3.1. Data

The analysis proposed in this paper is based on data from the Energy Institute Statistical Review [6], which covers multiple countries. In North Africa, limited data are in stark contrast to the various start years of hydroelectric projects in different regions, with some countries launching their efforts recently as 2011.
Figure 1 shows hydroelectric generation data for each country considered from 1965 to 2023. The figure indicates that, unlike other countries, Canada and the US have generated a substantial amount of electricity from hydropower, while most countries have maintained similar generation levels. It may be also noticed that India and Norway have significantly increased their hydroelectricity generation, whereas some countries have reduced their reliance on this source.
To analyze the evolution of hydropower in these countries, we have employed a variety of models, starting from diffusion models, namely the Bass model 3.2.1 and GGM 3.2.3, whose performance will be compared with other concurrent models, namely Prophet and ARIMA models.

3.2. Models

This section is dedicated to a description of the models used for the forecasting analysis.

3.2.1. Bass Model

The Bass model (BM) presents a depiction of the life cycle of an innovation, showing the stages of introduction, growth, maturity, and decline. It is crucial to note that this model was initially developed in the realm of marketing science and aims to demonstrate the evolution of a new product’s growth over time, but then it was found out that it is suitable also for studying the diffusion of energy technologies [9]. The model operates on the assumption that two primary sources of information influence consumption decisions: external factors such as the media and advertising, and internal factors such as imitation and learning from others. One notable advantage of the BM is its ability to effectively explain the initial phase of diffusion, which is attributed to the presence of innovators. There is a significant body of literature on the role of innovators, also known as early adopters [26]. However, it is the BM that explicitly accounts for their role. The BM is formally represented by a first-order differential equation.
z ( t ) = p + q z ( t ) m [ m z ( t ) ] , t > 0
Where z ( t ) is the cumulative number of adoptions at time t, z ( t ) is defined as the variation over time of adoptions. m is the market potential, the maximum number of realizable sales within the diffusion, and its value is assumed to be constant throughout the entire process. m - z ( t ) is proportional to the residual market. The residual market is affected by the coefficients p and q. Parameter p, called innovation coefficient, represents the effect of the external influence, due to the mass media communication and advertising. Parameter q, called imitation coefficient, is the internal influence, whose effect is modulated by the ratio z ( t ) / m . Parameters p and q are utilized to measure the two distinct classifications of consumers mentioned earlier, namely the innovators and the imitators.
The closed-form BM solution can be expressed as
z ( t ) = m ( 1 e ( p + q ) t ) ( 1 + q p e ( p + q ) t ) t > 0
Three parameters m, p, and q define the dynamics of the diffusion process in terms of cumulative sales, or z ( t ) , in Equation (2). The market potential m, is a scale parameter that enables the modeling of the diffusion process in absolute terms, whereas parameters p and q, as in Equation (2), act on the speed of diffusion. z ( t ) , as given by Equation (2) for a range of parameter values p and q. The cumulative process, as can be seen, has an s-shaped pattern and approaches saturation, denoted by the parameter m, at varying rates based on the values of the parameters p and q [9].

3.2.2. Dynamic Market Potential

After conducting a comprehensive examination of the research conducted by [12], it becomes evident that there exists a potential to generalize the concept of BM taking into account the dynamic nature of the market potential. In light of this, it is possible to formulate the variable m ( t ) in a way that accurately depicts the inherent complexities and fluctuations associated with market dynamics.
z ( t ) = m ( t ) p + q z ( t ) m ( t ) 1 z ( t ) m ( t ) + m ( t ) z ( t ) m ( t ) , t > 0
Equation (3) characterizes the instantaneous adoptions z ( t ) as a sum of a BM with m ( t ) and a factor m ( t ) z ( t ) / m ( t ) , which allocates a fraction of the market potential variation m ( t ) to z ( t ) , specifically the growth rate z ( t ) / m ( t ) . Within Equation (3), the market potential variation m ( t ) impacts the instantaneous adoptions z ( t ) , which can either be positive and reinforcing if m ( t ) is increasing, or negative if m ( t ) is decreasing. This demonstrates that the adoption of a product receives an additional advantage from an expanding market potential, while a declining market weakens the process. Equation (3) can be conveniently rearranged as follows.
z ( t ) m ( t ) z ( t ) m ( t ) m 2 ( t ) = z ( t ) m ( t ) = p + q z ( t ) m ( t ) 1 z ( t ) m ( t )
The generalization of BM, where the function m ( t ) depends on time, has closed-from-solution,
z ( t ) = m ( t ) ( 1 e ( p + q ) t ) ( 1 + q p e ( p + q ) t )
Equation (5) clearly demonstrates that m ( t ) is an independent function that influences the dynamics of the diffusion process, represented by parameters p and q. The specific form of m ( t ) can vary depending on the assumptions made about the market potential. In [12] and [11] certain structures for m ( t ) have been proposed. The GGM is based on one of these possibilities.

3.2.3. GGM

In [12] authors postulated a specific specification for m ( t ) , under the assumption that the growth of the market potential is contingent upon a communication process regarding the new product. This process typically precedes the adoption phase and serves the purpose of “building” the market. More precisely, the dynamic market potential m ( t ) is defined according to a structure that resembles a Bass model,
m ( t ) = K 1 e ( p c + q c ) t 1 + q c p c e ( p c + q c ) t
In Equation (6), the parameters p c and q c govern the communication process. The parameter p c characterizes the behavior of innovative consumers who initiate discussions about the new product, while q c represents the forces that propagate the information, causing it to become “viral”. The parameter K shows the asymptotic behavior of m ( t ) when all informed consumers ultimately become adopters. The GGM exhibits the following cumulative structure
z ( t ) = K 1 e ( p c + q c ) t 1 + q c p c e ( p c + q c ) t 1 e ( p s + q s ) t 1 + q s p s e ( p s + q s ) t , t > 0
In Equation (7), the cumulative adoptions, z ( t ) , are depicted as the product of two distinct phases, namely, the communication phase with parameters p c and q c , and the adoption process with parameters p s and q s .

3.2.4. Prophet Model

In [29] the authors proposed an innovative model able to handle time series with nonlinear trend, seasonality, and other possible effects appearing in the data. The mathematical components of the Prophet model are defined as,
y ( t ) = g ( t ) + s ( t ) + h ( t ) + ϵ t
In Equation (8) g ( t ) is the trend function that models non-periodic changes in the value of the time series, s ( t ) represents periodic changes (e.g., weekly and yearly seasonality), and h ( t ) represents the effects of holidays that occur on potentially irregular schedules over one or more days. The error term ϵ t represents any idiosyncratic changes that are not accommodated by the model, for which we assume that ϵ t is normally distributed. In this approach, both the nature of the time series (piece-wise trends, multiple seasonality, floating holidays) as well as the challenges involved in forecasting are accounted for. The first one is nonlinear growth denoted by g ( t ) in Equation (8). This sort of growth is typically modeled by the logistic growth model, defined as
g ( t ) = C a + e x p ( k ( t m ) )
where C is the carrying capacity, k the growth rate, and m an offset parameter. If the trend is linear then the growth model is defined as
g ( t ) = ( k + a ( t ) T δ ) t + ( m + a ( t ) T γ )
Whereas before k is the growth rate, δ has the rate adjustments, m is the offset parameter, and γ j is set to s j δ j to make the function continuous. s j is defined as the change points. The seasonality effect is approximated by a standard Fourier series given as,
s ( t ) = n = 1 N a n cos 2 π n t P + b n sin 2 π n t P
In Equation (10), N is the count of Fourier components, P shows periods, and a n , b n represents Fourier coefficients. The above components then amalgamate into an additive model. The effect of h ( t ) on holidays and events that provide predictable shocks often does not follow any specific periodic pattern [29].

3.2.5. Auto-Regressive Integrated Moving Average Model (ARIMA)

One of the traditional statistical techniques that is used frequently for time series forecasting is the ARIMA model (Auto Regressive Integrated Moving Average) [16]. To model and predict time series data, it integrates moving average (MA), differencing (I), and autoregressive (AR) components. ARIMA models accommodate trends and seasonality, as well as linear relationships within the data. A general ARIMA model can be written as
y t = c + ϕ 1 y t 1 + + ϕ p y t p + θ 1 ε t 1 + + θ q ε t q + ε t ,
where y t is the differenced series, and the “predictors” on the right-hand side include both lagged values of y t and lagged error terms. We call this an ARIMA( p , d , q ) model, where
  • p = order of the autoregressive part;
  • d = degree of first differencing involved;
  • q = order of the moving average part.
  • ε = is called the white nose and is assumed to be independent and identically distributed variables sampled from a normal distribution with zero mean.
To form more complicated models, the backshift notation is often used. For example, Equation (11) can be written in backshift notation as
( 1 ϕ 1 B ϕ p B p ) ( 1 B ) d y t = c + ( 1 + θ 1 B + + θ q B q ) ε t
Where ( 1 ϕ 1 B ϕ p B p ) is A R ( p ) part, ( 1 B ) d is d differences, while ( 1 + θ 1 B + + θ q B q ) is MA(q) part. Selecting appropriate values for p, d, and q can be difficult, but usually, this is performed by using selection criteria such as the AIC or error measures like the Root Mean Squared Error (RMSE) [16].

3.3. Evaluation Metrics

Three evaluation metrics are considered to measure the performance of the selected models after careful consideration: Mean Absolute Error (MAE), Root Mean Squared Error (RMSE), and Mean Absolute Percentage Error (MAPE).

3.3.1. Mean Absolute Error (MAE)

MAE works on averaging the squared discrepancies between expected and actual values. The Mean Absolute Error, or MAE, provides a quantitative assessment of prediction accuracy while highlighting the greater errors [16].
MAE = 1 n i = 1 n ( | y i y ^ i | )

3.3.2. Root Mean Squared Error (RMSE)

To understand RMSE, it is necessary to first show the formula for Mean Squared Error (MSE). MSE calculates the average of the squared discrepancies between the predicted and actual values. It provides a quantitative assessment of prediction accuracy, with a greater emphasis on larger errors [7].
MSE = 1 n i = 1 n y i y ^ i 2
Taking the square root of the MSE gives the Root Mean Squared Error (RMSE):
RMSE = MSE

3.3.3. Mean Absolute Percentage Error (MAPE)

The MAPE averages percentage difference between the expected and actual values is measured by MAPE (Mean Absolute Percentage Error), which offers a comparative assessment of predicting accuracy [14].
MAPE = 100 % n i = 1 n y i y ^ i y i

4. Results

In the results section, we evaluate the effectiveness of the models proposed in predicting hydropower generation data. This evaluation examines how well each model captures the observed patterns and trends in hydroelectric generation in different regions and periods. We consider metrics such as goodness of fit, accuracy, and predictive capability to identify the model that most accurately represents the data. The detailed findings are presented in the following subsections.

4.1. American Countries

In Figure 2, we illustrate a comparison between four forecasting models—Bass, Prophet, ARIMA, and GGM using data from American countries spanning the years 1965 to 2023. This dataset is split into a training set of 52 points (marked in black) and a test set of 7 points (marked in red), allowing us to assess each model’s performance across various contexts. The figure demonstrates the performance of each model in the countries analyzed. We may notice that the Bass model, displayed in green, generally underestimates data during rapid growth periods but performs well in countries like Mexico, where the data has a peak followed by a decline. Conversely, the GGM, shown in purple, often surpasses the Prophet (blue) and ARIMA (yellow) models, especially in North American countries such as Mexico and the US. This highlights that the GGM may be better suited for capturing complex trends and regional dynamics. The Prophet model is more accurate in scenarios of continuous growth but tends to misinterpret fluctuating data, resulting in either overestimation or underestimation. This behavior is seen consistently across different datasets. The Bass model once again underestimates during rapid growth but performs well in regions like the Caribbean, Chile, and Argentina, where data peaks followed by a decline. In contrast, the GGM consistently outperforms the Prophet and ARIMA models, particularly in Argentina, Ecuador, the Caribbean, and Venezuela. Although these visual insights are valuable, they must be supported by quantitative evaluations for a thorough assessment. Further analysis using quantitative metrics from the model-fitting results section is necessary to validate these observations and provide a complete evaluation of the models’ performance.

4.2. European Countries

Figure 3 shows a comparative analysis of the models applied to data from European countries. In the European case, it is evident the difficulty in determining the best-performing model due to the striking similarity in the hydroelectric generation patterns in these developed nations. This uniformity in hydroelectric power output causes all models to closely fit the data. Figure 3 illustrates that almost all models are in close agreement with the data, suggesting stability and minimal fluctuations in hydroelectric production in these European countries. To better assess the performance of the models, specific countries with more significant deviations have been selected. For instance, in Austria, the GGM and Prophet models exhibit similar performance, while the Bass model underestimates the data. In contrast, in countries like Iceland, where hydroelectric production is on the rise, all models overestimate the data. However, the GGM shows the closest alignment with the original data among the four models. Visually, the GGM’s performance is notably better compared to the Bass and Prophet models in most countries. This analysis will include more metrics to provide a clearer distinction between models, helping to identify the most precise and reliable model to forecast hydroelectric generation in European countries.

4.3. Asian and Middle East Countries

Figure 4 presents the alignment results of the hydroelectric generation model for Middle Eastern and Asian countries where data is available. Since hydroelectric generation in the Middle Eastern region tends to be lower compared to other regions, we combined the Middle Eastern countries for a more coherent analysis. The results show that in Middle Eastern countries, particularly in Iran, all models performed similarly. However, in Iraq and Egypt, the GGM model outperformed the others significantly, while the Bass and Prophet models occasionally either overestimated or underestimated hydroelectric generation. To further refine this analysis, we will evaluate performance metrics to determine which model offers the best predictive ability.
In contrast, Figure 4 also highlights the fit of the model for hydroelectric generation in Asian countries, including Australia, where substantial investments in hydroelectric projects have led to significant increases over time. Although most models fit the data well, there are noticeable performance differences. For instance, the GGM generally outperforms the Prophet and Bass models across most countries, except Vietnam, where performance varies. Similarly to the Middle Eastern countries, the Bass and Prophet models sometimes overestimate or underestimate hydroelectric generation. To complete this analysis, performance metrics will be considered to identify the best model in terms of prediction ability.

4.4. Evaluation Metrics

Table 1 presents the average performance metrics, namely Mean Absolute Error (MAE), Root Mean Squared Error (RMSE), and Mean Absolute Percentage Error (MAPE), for the evaluated models. The Bass model demonstrates an average MAE of approximately 9.7652, indicating that on average the model deviates about 9.7652 units from the actual hydropower generation values. The corresponding average RMSE of 10.456 reflects the typical magnitude of errors, while the MAPE, averaging around 24.525%, represents the average percentage deviation of the model predictions from the actual hydroelectric generation values. However, the GGM exhibits superior performance with an average MAE of approximately 5.1979, indicating smaller deviations from the actual hydroelectric generation values compared to the Bass model. The average RMSE of 5.898 suggests smaller errors in magnitude, and the MAPE, averaging 15.498%, indicates a lower average percentage deviation from the actual values. Regarding model performance, the Prophet Model shows moderate results, with an average MAE of approximately 5.216, falling between the Bass Model and the GGM. The corresponding average RMSE of 6.0988 represents the typical magnitude of errors, while the MAPE, averaging around 18.796%, represents the average percentage deviation from the actual hydroelectric generation values. The ARIMA model also shows strong performance, with an average MAE of approximately 5.788. This suggests smaller deviations from the actual values compared to the Bass model. The average RMSE of 6.7488 indicates the typical error magnitude, and the MAPE, averaging 16.1219%, suggests a lower average percentage deviation from the actual values. Overall, the GGM demonstrates superior performance compared to the Bass, ARIMA, and Prophet models in terms of average error metrics, suggesting that it may be the most accurate model for predicting hydropower generation in the evaluated dataset.
Table 2 presents a comparison of the mean absolute percentage error (MAPE) for the four models. The rows represent the models being evaluated, while the columns denote the models they are compared against. Starting with the Prophet model, it outperformed the Bass model in 30 of the 43 countries evaluated. Furthermore, Prophet did better than the ARIMA model in 21 countries and surpassed GGM in 17 countries. Next, looking at the ARIMA model, we see that it was outperformed by the Prophet model in 22 countries. The Bass Model outperformed ARIMA in 31 countries, and GGM did better in 17 countries. However, the GGM showed impressive results. It outperformed the Prophet model in 26 countries, the Bass model in 33 countries, and the ARIMA model in 26 countries. This highlights GGM’s consistent performance across different regions. The Bass Model had more mixed results. It was outperformed by the Prophet model in 13 countries, by the GGM in 10 countries, and by the ARIMA model in 12 countries.
From these results, it is clear that GGM generally has a lower MAPE, which indicates that it provides more accurate forecasts for hydropower data compared to the other models. This suggests that GGM is the most reliable model for predicting hydroelectric generation in various countries, making it a valuable tool for energy planning and forecasting.
By examining these comparisons, we can see that, while each model has its strengths, GGM consistently delivers the most accurate predictions. This analysis underscores the importance of selecting the right model for forecasting to ensure effective energy planning and management (the Appendix provides a detailed breakdown of the results).

5. Conclusions

The global community is currently grappling with critical challenges posed by climate change and the increasing demand for reliable, sustainable energy sources. The shift to renewable energy is widely considered a primary solution to these urgent issues. As a result, accurately predicting the rise of renewable energy sources has become essential for effective energy planning and management. Among these, hydroelectric still plays a central role.
Our research conducted an in-depth analysis of hydropower generation data from 43 countries, which we categorized into five distinct regions, covering the years 1965 to 2023. This extensive data set allowed us to evaluate and compare various models for forecasting hydroelectric production patterns in different geographic regions, including the Americas, Africa, Europe, Asia, and the Middle East. Significant variations in data generation were observed within each region. To address this, we used a train-test data split, using 53 data points for training and 6 points for testing, out of a total of 59.
In highly developed countries, maintaining consistent levels of power generation is challenging due to various factors, while in less developed countries, power generation tends to increase over time. From our graphical analysis, we observed notable changes in power generation in certain countries. The ARIMA model performed well in these scenarios, while the Bass model was more effective with increasing datasets. The Prophet model generated clear graphs with stable data, and the GGM model outperformed the others in cases with small variations in power generation, whether increasing or decreasing.
Among the models studied, the GGM consistently proved superior in accurately predicting hydroelectric power generation. It effectively captured complex nonlinear patterns in the data, and its performance was validated through quantitative metrics such as mean absolute error (MAE), root mean square error (RMSE), and mean absolute percentage error (MAPE). On average, across all countries, the GGM model (5.1979 MAE, 5.8983 RMSE, and 15.4978 MAPE) slightly outperformed the Prophet (5.2163 MAE, 6.0988 RMSE, and 18.7966 MAPE) and ARIMA (5.7881 MAE, 6.7488 RMSE, and 16.1219 MAPE) models and was significantly more accurate than the Bass Model (9.7652 MAE, 10.4561 RMSE, and 24.5253 MAPE). In all countries examined, the GGM consistently achieved lower MAPE scores than other models, demonstrating its greater reliability and precision in the prediction of hydroelectric generation.
Although the Bass model showed notable success in specific countries with distinctive data trends, such as Chile and regions in eastern Africa, the GGM outperformed all other models in a broader range of regions and conditions.
In summary, the findings of our analysis show an interesting ability of the GGM to capture the evolutionary patterns of hydropower in most analyzed countries. This opens a new perspective on the use of this kind of model, which has been generally employed with descriptive purposes [9], rather than predictive. In this sense, hydropower data have offered the possibility to deal with a variety of patterns, with a growing trend, with a flat, or, in some cases, with a declining behavior for which a sufficiently flexible structure is necessary. Whereas the Bass Model does not have this flexibility, the GGM can capture the nonlinearities of the data efficiently. These findings highlight the critical importance of models like the GGM in enhancing our understanding and forecasting capabilities in the context of energy transitions. The insights gained from these models can equip policymakers and energy planners to make more informed decisions, steering their countries toward sustainable energy futures on a global scale.

Author Contributions

Conceptualization, M.G., F.A. and L.F.; methodology, M.G.; software, M.G.; validation, F.A., M.G., and L.F.; formal analysis, F.A., and M.G.; investigation, M.G., and L.F.; resources, F.A. and M.G.; data curation, F.A.; writing–original draft preparation, F.A. and M.G.; writing–review and editing, M.G and F.A.; visualization, F.A. and M.G.; supervision, M.G., and L.F.; project administration, F.A., G.M., and L.F.; All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Data Availability Statement

Data used in this study is available at https://www.energyinst.org/statistical-review

Conflicts of Interest

The authors declare no conflicts of interest.

 

Table A1. Overall models results.
Table A1. Overall models results.
Country Model MAE MSE RMSE MAPE
Canada BM 66.0842697 4504.8002387 67.1178087 17.2188732
GGM 24.4790566 689.5971616 26.2601821 6.3296417
Prophet 10.1587427 130.9905848 11.4451118 2.6491495
ARIMA 30.1045593 1144.9760207 33.8374943 7.9536895
Mexico BM 5.2454048 33.5386168 5.7912535 20.2788509
GGM 5.2638338 32.0753076 5.6635066 19.3594590
Prophet 5.3898187 48.1223380 6.9370266 22.6726527
ARIMA 5.3937792 47.4668499 6.8896190 22.6722391
US BM 41.9250130 1974.4022465 44.4342463 15.4393961
GGM 16.5125208 293.9787199 17.1458076 6.1989374
Prophet 20.3072578 739.1742449 27.1877591 8.2243748
ARIMA 16.4344742 472.9964088 21.7484806 6.6508693
Argentina BM 5.0460849 39.3179516 6.2704028 17.9021872
GGM 3.5565751 17.1466323 4.1408492 14.3646525
Prophet 7.4901847 75.2792764 8.6763631 32.6302025
ARIMA 9.6669316 114.1637288 10.6847428 41.3217673
Chile BM 1.4997635 4.5428143 2.1313879 6.9577939
GGM 2.5056871 9.4229953 3.0696898 12.5504025
Prophet 3.2257494 14.4774182 3.8049203 16.0332807
ARIMA 2.6240310 10.9359677 3.3069575 13.1871190
Colombia BM 18.4774657 374.9943061 19.3647697 31.4826222
GGM 5.5118651 36.9241645 6.0765257 9.3132428
Prophet 8.0729056 83.5419017 9.1401259 13.4896407
ARIMA 3.9614912 26.2897768 5.1273557 7.3376092
Ecuador BM 14.7008842 220.3509188 14.8442217 60.4232303
GGM 6.6170600 45.1676416 6.7206876 27.2925960
Prophet 9.4465509 90.9595007 9.5372690 38.8338915
ARIMA 1.6990184 3.1618271 1.7781527 6.9788381
Peru BM 6.2932649 40.7851161 6.3863226 20.4936958
GGM 3.8855863 17.3878519 4.1698743 12.5751891
Prophet 5.0903552 27.7682123 5.2695552 16.5320012
ARIMA 1.3965065 2.8074849 1.6755551 4.6407140
Venezuela BM 10.6717530 157.5804984 12.5531071 15.9292858
GGM 4.4761906 29.4964444 5.4310629 6.8774296
Prophet 16.2060473 265.5713985 16.2963615 24.5748624
ARIMA 8.4555605 75.9650872 8.7157953 12.8184292
Central America BM 7.2916267 64.8107618 8.0505131 25.8424549
GGM 2.5196772 10.1968499 3.1932507 10.1386136
Prophet 3.8625350 19.7255155 4.4413416 13.6563005
ARIMA 2.5228483 9.5054117 3.0830848 9.9951753
Other Caribbean BM 0.2223351 0.0666057 0.2580809 11.4291869
GGM 0.3374809 0.1347491 0.3670818 18.8181172
Prophet 0.3338083 0.1316452 0.3628294 18.5875380
ARIMA 0.7977321 0.7133839 0.8446205 44.6848357
Other South America BM 25.6681849 686.3453703 26.1981940 43.6293782
GGM 18.9569180 427.9374278 20.6866485 34.0270408
Prophet 12.9704927 209.1748393 14.4628780 23.4705416
ARIMA 16.9093777 347.9695683 18.6539424 30.4604138
Country Model MAE MSE RMSE MAPE
Austria BM 5.4462594 35.4085258 5.9505063 13.7619874
GGM 1.8915194 6.3805977 2.5259845 5.0426955
Prophet 2.3036428 8.4475921 2.9064742 6.2538154
ARIMA 2.9182853 14.0803561 3.7523801 7.9773424
Czech Republic BM 0.1859873 0.0584269 0.2417166 9.5312934
GGM 0.1856165 0.0584217 0.2417059 9.5394358
Prophet 0.2360734 0.0917547 0.3029104 12.6215928
ARIMA 0.2622903 0.0869694 0.2949058 12.3345700
Finland BM 1.3664158 2.7834548 1.6683689 9.0884168
GGM 1.5660685 3.7213446 1.9290787 10.3300331
Prophet 1.2295043 1.6839889 1.2976860 8.7788720
ARIMA 1.2198664 1.9634556 1.4012336 8.9658790
France BM 11.0141810 149.3647609 12.2214877 18.5493976
GGM 5.7548662 40.5020560 6.3641226 10.3617908
Prophet 7.1390507 89.6719836 9.4695292 14.1733833
ARIMA 5.8163152 60.7172215 7.7921256 11.2178639
Germany BM 1.5881680 3.4403264 1.8548117 8.7309180
GGM 0.9718622 1.0544572 1.0268677 5.1690873
Prophet 2.2771408 6.0335442 2.4563274 12.4003265
ARIMA 1.4781678 3.0324464 1.7413921 8.1353358
Iceland BM 4.2146884 19.2031891 4.3821443 30.5155443
GGM 1.0431425 1.3488512 1.1614005 7.5607219
Prophet 0.7045184 0.6009440 0.7752058 5.1561171
ARIMA 1.1865707 1.5349012 1.2389113 8.6416974
Norway BM 22.3395177 552.3940465 23.5030646 16.2979338
GGM 10.2275571 139.3417575 11.8043110 7.3584154
Prophet 6.5525203 48.6022193 6.9715292 4.8479555
ARIMA 12.6250792 214.7500321 14.6543520 9.6042767
Poland BM 0.3303318 0.1353097 0.3678446 16.2736275
GGM 0.1861305 0.0711348 0.2667110 8.0822982
Prophet 0.2154036 0.0652897 0.2555185 10.7285196
ARIMA 0.2317687 0.0767290 0.2770000 11.5604302
Romania BM 4.9826463 27.7820157 5.2708648 29.8400631
GGM 2.6815349 9.8874835 3.1444369 15.6545919
Prophet 1.3915730 2.2479552 1.4993183 8.6646793
ARIMA 1.3473533 3.0170228 1.7369579 8.8558633
Slovakia BM 1.4677063 2.3046143 1.5180956 36.3304547
GGM 0.5577166 0.4780515 0.6914127 14.4784880
Prophet 0.9258432 1.0150172 1.0074806 23.3135901
ARIMA 0.3487080 0.1960251 0.4427472 8.9073703
Spain BM 4.8372902 39.5747504 6.2908466 22.2596955
GGM 9.7003960 124.0123650 11.1360839 43.1468892
Prophet 4.9742992 41.5867009 6.4487751 22.9461819
ARIMA 4.8192681 36.8795948 6.0728572 21.8419873
Switzerland BM 2.6132591 8.5664982 2.9268581 7.5833502
GGM 3.0125261 10.6347716 3.2610998 8.5523374
Prophet 1.9552595 8.5733463 2.9280277 6.0794828
ARIMA 2.3194117 13.5686762 3.6835684 7.3122751
Turkey BM 28.4400760 924.2676053 30.4017698 39.9405230
GGM 9.9675826 171.1472200 13.0823247 13.4455122
Prophet 12.1743337 267.9655743 16.3696541 15.7275200
ARIMA 9.3296113 155.8771469 12.4850770 12.5526322
Other Europe BM 14.9316052 248.9817963 15.7791570 40.1621697
GGM 5.0266596 38.9922987 6.2443814 12.8857958
Prophet 5.8329177 51.2867408 7.1614762 14.9191503
ARIMA 7.4257156 75.9957521 8.7175542 19.2168466
Country Model MAE MSE RMSE MAPE
Iran BM 6.9845990 94.0041205 9.6955722 29.8907715
GGM 6.9621666 91.2623229 9.5531316 30.1792819
Prophet 6.9486845 86.4862953 9.2998008 31.1460150
ARIMA 7.0090000 69.7343173 8.3507076 36.9366992
Iraq BM 2.5826157 7.7512828 2.7841126 72.8283569
GGM 0.8142556 1.0241314 1.0119938 28.5069276
Prophet 1.3566285 2.5682044 1.6025618 53.8265823
ARIMA 1.3311835 2.4834816 1.5759066 35.3691181
Other Middle East BM 0.4954593 0.3513755 0.5927693 36.5357261
GGM 0.6865652 0.5995384 0.7742986 49.5678705
Prophet 2.0667063 4.3259500 2.0798918 141.9515216
ARIMA 0.3383080 0.1461239 0.3822616 21.0196483
Egypt BM 2.5110039 6.9451962 2.6353740 17.9827015
GGM 0.6452614 0.6113224 0.7818711 4.5618663
Prophet 0.6421577 0.6217804 0.7885305 4.5254181
ARIMA 0.6122890 0.6886871 0.8298717 4.2852172
Eastern Africa BM 0.7572179 0.9703197 0.9850481 1.0499911
GGM 0.6716996 0.9471116 0.9731966 0.9361015
Prophet 5.2784516 40.4743566 6.3619460 6.7510398
ARIMA 6.4304142 52.6912961 7.2588771 8.3140052
Australia BM 2.7970137 9.3485534 3.0575404 17.4598564
GGM 1.7075183 4.1138105 2.0282531 10.4882302
Prophet 1.0355469 1.3720416 1.1713418 6.6322687
ARIMA 2.1032379 5.7853018 2.4052654 12.9935551
India BM 10.8661305 139.3920315 11.8064403 6.7774007
GGM 9.4595922 128.0283392 11.3149609 6.0529437
Prophet 19.9960172 507.5936439 22.5298390 12.2355462
ARIMA 15.4506733 347.9091390 18.6523226 9.3586446
Indonesia BM 8.6518393 79.3014666 8.9051371 35.5816079
GGM 4.3706414 21.0994345 4.5934121 17.8933986
Prophet 7.0656199 53.0799937 7.2856018 29.0442821
ARIMA 4.8304685 26.8643168 5.1830799 19.7830646
Japan BM 2.1477368 6.7294859 2.5941253 2.7466141
GGM 2.5287287 10.9769519 3.3131483 3.3744494
Prophet 6.7437972 53.2167127 7.2949786 8.8918553
ARIMA 4.0173795 23.6275183 4.8608146 5.3466671
Malaysia BM 15.6746804 249.1243383 15.7836732 54.1055571
GGM 14.1350465 201.5822452 14.1979662 48.8989211
Prophet 6.3201616 40.7913102 6.3868075 21.8257963
ARIMA 10.8076573 130.9042179 11.4413381 36.7537446
New Zealand BM 6.1320725 39.4782035 6.2831683 23.8990721
GGM 3.3648502 12.4139614 3.5233452 13.0549705
Prophet 1.0648053 1.2768798 1.1299910 4.1288790
ARIMA 1.0896510 1.7940917 1.3394371 4.3811396
Pakistan BM 14.2613183 220.9642790 14.8648673 38.9999476
GGM 3.1400424 13.7241215 3.7046081 8.5777542
Prophet 5.5001061 37.5695582 6.1294011 14.7370059
ARIMA 2.9634511 11.8654716 3.4446294 8.2557543
Philippines BM 1.0149268 1.4040747 1.1849366 11.7601556
GGM 1.0009784 1.9877948 1.4098918 12.6727268
Prophet 0.9157312 1.5913179 1.2614745 11.5093363
ARIMA 0.7970325 1.4894786 1.2204420 10.2586298
South Korea BM 0.8503699 0.9464235 0.9728430 23.8664714
GGM 0.4354003 0.2775283 0.5268096 12.3352467
Prophet 0.3419239 0.1828225 0.4275775 11.0047753
ARIMA 0.4476506 0.2740110 0.5234606 12.5720995
Country Model MAE MSE RMSE MAPE
Taiwan BM 1.5197248 3.3751510 1.8371584 30.9698589
GGM 0.9684150 1.4439601 1.2016489 20.3520254
Prophet 1.0213260 1.2629225 1.1237982 26.6071623
ARIMA 1.2032583 2.0592151 1.4349966 33.3744756
Thailand BM 1.2782954 1.9572457 1.3990160 20.3053724
GGM 0.9296723 1.4679627 1.2115951 18.2717879
Prophet 0.8890638 1.4179258 1.1907669 17.3762354
ARIMA 1.4399657 3.0686854 1.7517664 21.3886357
Vietnam BM 34.4984843 1478.5136118 38.4514449 43.9377585
GGM 24.2945265 767.5679138 27.7050160 31.2298631
Prophet 6.6473449 76.9770441 8.7736563 8.0971371
ARIMA 36.7219175 1513.9384908 38.9093625 47.0253358

References

  1. Aminifar, F.; Shahidehpour, M.; Alabdulwahab, A.; Abusorrah, A.; Al-Turki, Y. The proliferation of solar photovoltaics: Their impact on widespread deployment of electric vehicles. IEEE Electrification Magazine, 2020; 8, 79–91. https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=9185064.
  2. Bakis, R. The current status and future opportunities of hydroelectricity. Energy Sources, Part B, 2007; 2, 259–266. https://www.tandfonline.com/doi/pdf/10.1080/15567240500402958.
  3. Bessi, A.; Guidolin, M.; Manfredi, P. Diffusion of renewable energy for electricity: An analysis for leading countries. In International Conference on Time Series and Forecasting, 2021, 291–305, Springer. https://link.springer.com/chapter/10.1007/978-3-031-14197-3_19.
  4. Bessi, A.; Guidolin, M.; Manfredi, P. The role of gas on future perspectives of renewable energy diffusion: Bridging technology or lock-in? Renewable and Sustainable Energy Reviews, 2021, 152, 111673. https://www.sciencedirect.com/science/article/pii/S1364032121009473.
  5. de Freitas Cavalcanti, J. T.; de Lima, J. G.; do Nascimento Melo, M. R.; Monteiro, E. C. B.; Campos-Takaki, G. M. Fossil fuels, nuclear energy and renewable energy. Seven Editora, 2023. https://sevenpublicacoes.com.br/index.php/editora/article/view/1693.
  6. Energy Institute, Statistical Review of World Energy. Energy Institute, 2024. Available at: https://www.energyinst.org/statistical-review. 2024-06-17.
  7. Geem, Z. W.; Roper, W. E. Energy demand estimation of South Korea using artificial neural network. Energy Policy, 2009, 37, 4049–4054. https://www.sciencedirect.com/science/article/pii/S0301421509003218.
  8. Ghadimi, N.; Akbarimajd, A.; Shayeghi, H.; Abedinia, O. Two stage forecast engine with feature selection technique and improved meta-heuristic algorithm for electricity load forecasting. Energy, 2018, 161, 130–142. https://www.sciencedirect.com/science/article/pii/S0360544218313859.
  9. Guidolin, M. Innovation Diffusion Models: Theory and Practice. John Wiley & Sons, 2023. https://www.wiley.com/en-au/Innovation+Diffusion+Models%3A+Theory+and+Practice-p-9781119756231.
  10. Guidolin, M.; Mortarino, C. Cross-country diffusion of photovoltaic systems: Modelling choices and forecasts for national adoption patterns. Technological Forecasting and Social Change, 2010, 77, 279–296. https://www.sciencedirect.com/science/article/pii/S0040162509000997.
  11. Guseo, R.; Guidolin, M. Cellular automata with network incubation in information technology diffusion. Physica A: Statistical Mechanics and its Applications, 2010, 389, 2422–2433. https://www.sciencedirect.com/science/article/pii/S0378437110001317.
  12. Guseo, R.; Guidolin, M. Modelling a dynamic market potential: A class of automata networks for diffusion of innovations. Technological Forecasting and Social Change, 2009, 76, 806–820. https://www.sciencedirect.com/science/article/pii/S0040162508001807.
  13. He, P.; Ni, X. Renewable energy sources in the era of the fourth industrial revolution: A perspective of civilization development. In Journal of Physics: Conference Series, 2022, 2301, 012030. IOP Publishing. https://iopscience.iop.org/article/10.1088/1742-6596/2301/1/012030/meta.
  14. Herrera, G. P.; Constantino, M.; Tabak, B. M.; Pistori, H.; Su, J.-J.; Naranpanawa, A. Long-term forecast of energy commodities price using machine learning. Energy, 2019, 179, 214–221. https://www.sciencedirect.com/science/article/pii/S036054421930708X.
  15. Huang, J.; Tang, Y.; Chen, S. Energy demand forecasting: Combining cointegration analysis and artificial intelligence algorithm. Mathematical Problems in Engineering, 2018, 1–13. https://onlinelibrary.wiley.com/doi/full/10.1155/2018/5194810.
  16. Hyndman, R. J.; Athanasopoulos, G. Forecasting: Principles and Practice. OTexts, 2018. https://otexts.com/fpp3/.
  17. International Energy Agency, “Hydroelectricity,” International Energy Agency, Available online: https://www.iea.org/energy-system/renewables/hydroelectricity ( Aug. 30, 2024).
  18. Kabeyi, M. J. B.; Olanrewaju, O. A. Sustainable energy transition for renewable and low carbon grid electricity generation and supply. Frontiers in Energy Research, 2022, 9, 1032. https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2021.743114/full.
  19. Karumanchi, H.; Mathew, S. Forecasting of hydropower generation of India using autoregressive integrated moving average model. Journal of Algebraic Statistics, 2022, 13, 3124–3128. https://publishoa.com/index.php/journal/article/view/991.
  20. Lizunkov, V.; Politsinskaya, E.; Malushko, E.; Kindaev, A.; Minin, M. Population of the world and regions as the principal energy consumer. International Journal of Energy Economics and Policy, 2018, 8, 250–257. https://www.zbw.eu/econis-archiv/bitstream/11159/2120/1/1028134991.pdf.
  21. Malha n, P.; Mittal, M. A novel ensemble model for long-term forecasting of wind and hydropower generation. Energy Conversion and Management, 2022, 251, 114983. https://www.sciencedirect.com/science/article/pii/S0196890421011596.
  22. Malhotra, R. Fossil energy: Introduction. In Fossil Energy, 2020, 1–4. https://link.springer.com/referenceworkentry/10.1007/978-1-4939-9763-3_920.
  23. Mite-León, M.; Barzola-Monteses, J. Statistical model for the forecast of hydropower production in Ecuador. International Journal of Renewable Energy Research, 2028, 8, 1130–1137. https://www.sciencedirect.com/science/article/abs/pii/0040162577900312.
  24. Office of Energy Efficiency & Renewable Energy, Title of the document or webpage. U.S. Department of Energy, 2022. Available at: https://www.energy.gov/eere. 2024-08-27.
  25. Polprasert, J.; Nguyen, V. A. H.; Charoensook, S. N. Forecasting models for hydropower production using ARIMA method. In 20219th International Electrical Engineering Congress (IEECON),2021 197–200. IEEE. https://ieeexplore.ieee.org/abstract/document/9440293.
  26. Rogers, E. M. Diffusion of Innovations, New York: The Free Press, 2003. https://www.taylorfrancis.com/chapters/edit/10.4324/9780203887011-36/diffusion-innovations-everett-rogers-arvind-singhal-margaret-quinlan.
  27. Savio, A.; De Giovanni, L.; Guidolin, M. Modelling energy transition in Germany: An analysis through ordinary differential equations and system dynamics. Forecasting, 2022, 4, 438–455. https://www.mdpi.com/2571-9394/4/2/25.
  28. Shamout, M. D.; Khamkar, K. A.; Lal, A.; Danaiah, P.; Mukasheva, A.; Kaushik, N. Hydropower technology as a renewable energy source of power generation and its effect on environment sustainability. In 2022 International Interdisciplinary Humanitarian Conference for Sustainability (IIHC),2022 1017–1020. IEEE. https://ieeexplore.ieee.org/abstract/document/10059855.
  29. Taylor, S. J.; Letham, B. Forecasting at scale. The American Statistician, 2018, 72, 37–45. https://www.tandfonline.com/doi/full/10.1080/00031305.2017.1380080.
  30. Zeng, B.; He, C.; Mao, C.; Wu, Y. Forecasting China’s hydropower generation capacity using a novel grey combination optimization model. Energy, 2023, 262, 125341. https://www.sciencedirect.com/science/article/pii/S0360544222022241.
Figure 1. Hydroelectricity generation by all countries
Figure 1. Hydroelectricity generation by all countries
Preprints 120447 g001
Figure 2. American countries: model fits and forecasting
Figure 2. American countries: model fits and forecasting
Preprints 120447 g002
Figure 3. European countries: model fits and forecasting
Figure 3. European countries: model fits and forecasting
Preprints 120447 g003
Figure 4. Asian and Middle East countries: model fits and forecasting
Figure 4. Asian and Middle East countries: model fits and forecasting
Preprints 120447 g004
Table 1. Model comparison based on MAE, RMSE, and MAPE.
Table 1. Model comparison based on MAE, RMSE, and MAPE.
Model MAE RMSE MAPE
BM 9.765295 10.456071 24.52534
GGM 5.197930 5.898378 15.49786
Prophet 5.216293 6.098824 18.79666
ARIMA 5.788099 6.748870 16.12192
Table 2. Model comparison based on MAPE. The rows represent the models being evaluated, while the columns denote the models being compared against.
Table 2. Model comparison based on MAPE. The rows represent the models being evaluated, while the columns denote the models being compared against.
Prophet ARIMA BM GGM
Prophet 0 21 30 17
ARIMA 22 0 31 17
BM 13 12 0 10
GGM 26 26 33 0
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.
Copyright: This open access article is published under a Creative Commons CC BY 4.0 license, which permit the free download, distribution, and reuse, provided that the author and preprint are cited in any reuse.
Prerpints.org logo

Preprints.org is a free preprint server supported by MDPI in Basel, Switzerland.

Subscribe

© 2024 MDPI (Basel, Switzerland) unless otherwise stated