Top PDF Weather neutral models for short-term electricity demand forecasting

Weather neutral models for short-term electricity demand forecasting

Weather neutral models for short-term electricity demand forecasting

Energy demand forecasting, and specifically electricity demand forecasting, is a fun- damental feature in both industry and research. Forecasting techniques assist all electricity market participants in accurate planning, selling and purchasing decisions and strategies. Generation and distribution of electricity require appropriate, precise and accurate forecasting methods. Also accurate forecasting models assist producers, researchers and economists to make proper and beneficial future decisions. There are several research papers, which investigate this fundamental aspect and attempt var- ious statistical techniques. Although weather and economic effects have significant influences on electricity demand, in this study they are purposely eliminated from investigation. This research considers calendar-related effects such as months of the year, weekdays and holidays (that is, public holidays, the day before a public holiday, the day after a public holiday, school holidays, university holidays, Easter holidays and major religious holidays) and includes university exams, general election days, day after elections, and municipal elections in the analysis. Regression analysis, cate- gorical regression and auto-regression are used to illustrate the relationships between response variable and explanatory variables.
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GA-ANN Short-Term Electricity Load Forecasting

GA-ANN Short-Term Electricity Load Forecasting

Abstract. This paper presents a methodology for short-term load forecasting based on genetic algorithm feature selection and artificial neural network modeling. A feedforward artificial neural network is used to model the 24-h ahead load based on past consumption, weather and stock index data. A genetic algo‐ rithm is used in order to find the best subset of variables for modeling. Three datasets of different geographical locations, encompassing areas of different dimensions with distinct load profiles are used in order to evaluate the method‐ ology. The developed approach was found to generate models achieving a minimum mean average percentage error under 2 %. The feature selection algo‐ rithm was able to significantly reduce the number of used features and increase the accuracy of the models.
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Short-term hourly load forecasting in South Africa using neutral networks

Short-term hourly load forecasting in South Africa using neutral networks

Rouse (2006) defined fuzzy logic as a computing technique based on “degrees of truth” instead of the well-known Boolean logic “true or false” (1 or 0). Fuzzy logic is rather a generalisation of this Boolean logic on which modern computers are based. Ranaweera, Hubele and Karady (1996) described fuzzy logic models as a function that links a set of input variables to a set of output variables; these input variable values do not need to be numerical. They just need to be transcribed in a natural language. For example, a weather parameter such as the temperature may take on the “fuzzy” instances such as “low”, “medium” and “high”. The literature adds that very often fuzzy logic models incorporate a mapping of input and output values via a simple “IF THEN” logic statement. “IF the temperature is very low, THEN the load demand will be very high”, is an example of this logic statement given in the Ranaweera et al. (1996) paper. The authors further reiterated that this is a type of mapping and logic that allows a combination of the expert knowledge with fuzzy logic models. In many instances when precise outputs are needed, such as point estimates for forecast values, a reverse mapping called “defuzzification” process can be undertaken to produce those desirable outputs. Advantages of this method over traditional ones can be found in Gupta (2012). The drawbacks of the fuzzy logic models are that they are time consuming and lack of guarantees to obtain optimal fuzzy rules and membership functions since this process is based on trial and error.
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Short term electricity demand forecasting using partially linear additive quantile regression with an application to the unit commitment problem

Short term electricity demand forecasting using partially linear additive quantile regression with an application to the unit commitment problem

The paper presented an application of partially linear additive quantile regression models to short term electricity demand forecasting using South African data. The study focused on the peak hours of the day. Variable selection was done using Lasso via hierarchical pairwise interactions. Models for each hour were split into one with and one without pairwise interactions. Models of each hour were combined using an algorithm in which the average loss suffered was based on the pinball loss function. This resulted in three sets of forecasts for each hour. The best set of forecasts was selected based on probabilistic forecast error measures, pinball loss values, continuous ranked probability scores and the log scores. For instance, as shown in 2 the model without interactions has smaller pinball loss value as compared to the other two models considered for hour 18:00 and was found to be the best fitting model. while from hours 19:00 and 20:00 model with interactions and the combined model were the best fitting models respectively.
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Novel autoregressive basis structure model for short-term forecasting of customer electricity demand

Novel autoregressive basis structure model for short-term forecasting of customer electricity demand

Reference [4] developed a method of forecasting south- east Brazil's hourly electricity demand and compared the results against a benchmark model. The development of the forecast model involved treating each hour of the day as a separate time series. Each model is based on a two- step decomposition of the time series. The first step is comprised of Fourier series, dummy variables and a linear trend. The purpose of the first step is to integrate seasonality, day of the week and special event effects into the forecast model. The second step involved estimating linear autoregressive models by regression and NN. The benchmark model in this study was a modified version of the Seasonal Integrated Autoregressive Moving Average (SARIMA) model. It was found that their proposed model outperformed the benchmark model and that the second step NN estimation performed comparatively poorly at horizon forecasting.
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FUZZY AND NEURO-FUZZY MODELS FOR SHORT-TERM WATER DEMAND FORECASTING IN TEHRAN *

FUZZY AND NEURO-FUZZY MODELS FOR SHORT-TERM WATER DEMAND FORECASTING IN TEHRAN *

is a complicated function of a large number of interacting variables. In this paper, several fuzzy and neuro-fuzzy models are presented and their results for short-term water demand forecasting in Tehran are compared. Weather data from three Tehran weather stations is weighted with the Thissen method and effective input data parameters are selected with regression of weighted effective weather and consumption data. The effective parameters include daily average temperature, relative humidity percent and last day, last week and last year water consumption. Consumption of all days between last day and the last week were also used. For the construction of fuzzy models a fuzzy rule-based approach is applied. The working rules are formulated from a set of past observations such as the relation between the parameters and the given input/output data sets. For neuro fuzzy modeling the toolbox function of Adaptive Neuro-Fuzzy Inference System (ANFIS) constructs a Sugeno Inference System (SFIS). The membership function parameters are adjusted using a back propagation algorithm in combination with a least squares method. Outputs of the fuzzy and the neuro fuzzy models demonstrate that the results of fuzzy models do not show high accuracy, but neuro fuzzy models produce better results. Besides, outputs of the neuro fuzzy models with just water consumption inputs have high accuracy. A comparison of outputs with the results of the Artificial Neural Networks (ANN) approach shows the capability of the ANFIS model to predict Tehran water consumption.
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Density forecasting for long-term peak electricity demand

Density forecasting for long-term peak electricity demand

The natures of long-term and short-term demand forecasts are quite different. For short-term forecasting, we are often interested in point forecasts (i.e., forecasts of the mean or median of the future demand distribution). For long-term forecasting, point forecasts are of limited interest as they cannot be used to evaluate and hedge the financial risk accrued by demand variability and forecasting uncertainty. Instead, density forecasts (providing estimates of the full probability distributions of the possible future values of the demand) are more helpful and necessary for long-term planning. For example, the National Electricity Market (NEM) of Australia asks for different levels of the Probability of Exceedance (POE) to be provided with forecasting (Power Systems Planning and Development, 2005). Another difference between short-term and long-term demand forecasting is in their use of meteorological information. It is well known that meteorological variables are the key inputs for most demand models. For short-term forecasts (up to one week ahead), such information can be obtained from weather services; but it is unavailable for long-term forecasts and so we require a feasible method to generate realistic future temperatures.
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Short-term and Medium-term Gas Demand Load Forecasting by Neural Networks

Short-term and Medium-term Gas Demand Load Forecasting by Neural Networks

There is rich literature providing references about short-term load forecasting with ANN [7-11]. Of many structures of ANNs, two structures are commonly used: the MultiLayer Perceptron (MLP) and the Kohonen network. Bakirtzis et al. [7] used a MLP ANN model for the electric power prediction using weather parameters and concluded that the prediction model has better accuracy than the statistical models. Khotanzad, et al. [9] also used the ANN model to predict the short term electric load. The availability of historical load data on the utility databases makes this area highly suitable for ANN implementation. ANNs are able to learn the relationship between the past, present, and the future weather variables and loads, combining both time series and regressional approaches. As is the case with time series approach, the ANN traces previous load patterns and predicts (i.e., extrapolates) a load pattern using recent load data. It can also use weather information for modeling. The ANN is able to perform non-linear modeling and adaptation. It does not need assumption of any functional relationships between load and weather variables in advance. We can adapt the ANN by exposing it to new data. Their ability to outperform traditional methods, especially during rapidly changing weather conditions and the short time required to their development, has made ANN based load forecasting models very attractive alternative for on-line implementation in energy control centers [2].
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Short-term Forecasting of the Abu Dhabi Electricity Load Using Multiple Weather Variables

Short-term Forecasting of the Abu Dhabi Electricity Load Using Multiple Weather Variables

Perfect knowledge of the weather variables over the forecast horizon (1 week) is assumed. Forecasting accuracy was compared between the ARIMA model, the TF model and the ANN model. Thirty forecast of one week each were generated, starting at midnight, for 30 consecutive days covering the period from the last week of May until the last week of June 2011. Table 3 presents the forecasting accuracy (MAPE) for the three models averaged over each of three different forecast horizons: first 24 hours (1:24), first 48 hours (1:48) and the full week (1:168). For the ANN model, due to large number of parameters to be identified, the non-convex nature of the estimation problem and the random starting parameters utilized for the training, each run produced slightly different results. The ANN model with best performing cross- validation after 10 runs was used for comparison to ARIMA and TF.
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Seasonal Short-Term Electricity Demand Forecasting under Tropical Condition using Fuzzy Approach Model

Seasonal Short-Term Electricity Demand Forecasting under Tropical Condition using Fuzzy Approach Model

needed since it can help to make right decision in expansion planning of electricity system and has big impact to profits [3,4]. Besides, it can reduce costs of operation and maintenance, and enhance continuity level of power supply [3]. With regards to this, one of the main methods that has been used successfully is fuzzy approach. Related to uncertainties of load characteristics and ability of fuzzy method to include human knowledge or experience in model such as in selecting input variables, and also to make smaller rule set when we have a lot of data caused fuzzy approach is suitable and interesting for load forecasting application [7,8]. Concerning its applications, paper of [2] proposeda fuzzy linear regression model for STLF which is composed for summer and winter seasons using weather parameters. In [8], the authors presented forecasting study for power system in India. In their case, fuzzy based STLF which implemented for peak, medium, and off-peak demand seasons gives better result than conventional method. Time and temperature variables are used as inputsfor the model. Meanwhile in the paper of [7], the authors conducted STLF study for Jordan context. A fuzzy inference model is presented with input namely last day and last week consumptions, last day and forecasted temperatures, weather, and type of day. Recently, short-term forecasting for electricity demand in Turkey using fuzzy logic and ANFIS is presented in [1]. Four day type models for each method are composed that is Monday, Weekday, Saturday, and Sunday models. Historical load demand, difference of temperature, and season data are inputs in their models.
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Short-term forecasting of the electric demand of HVAC systems

Short-term forecasting of the electric demand of HVAC systems

The first statistical regression model used in the building engineering field for energy consumption was introduced by Fels in 1986 [29]. The Princeton Scorekeeping Method (PRISM) is a univariate linear regression model linking the building energy consumption to the daily average outdoor air temperature. In the PRISM method, the building energy consumption is correlated to one weather regressor, the outdoor dry bulb temperature. These specific models are also called energy signatures. Other regressors characterizing the climate conditions are added to the temperature in statistical regression models, such as the relative humidity or the solar radiations when available. They have showed a better performance, at estimating the value of the heat loss coefficient of the building for instance [30]. The inclusion of time factors, such as day-type index, as a regressor of statistical regression models improved their performance [31]. A nonlinear relationship between the building energy consumption and the regressors can be described by polynomial regression models. The polynomial models are still considered as a linear regression in terms of the unknown parameters (coefficient of regression) which are estimated based on the measurements.
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A novel hybrid technique for short-term electricity price forecasting in deregulated electricity markets

A novel hybrid technique for short-term electricity price forecasting in deregulated electricity markets

Chapter2. Project Research  ‐ 15 ‐  may need forecasting as well. Therefore, the selection of a suitable forecasting technique with proper input factors is vitally important for accurately forecasting electricity prices. In this thesis, the influential factors are not taken into account when forecasting the short- term electricity prices. The reasons for doing this are as follows. First of all, such influential factors, such as the amount of different types of reserve, power import and predicted power shortfall do not improve the forecast at all [53]. Secondly, the effect of temperature is incorporated with the load demand. According to ref. [54], considering the historical load demand as the input factor does not significantly improve the predictions of ANN and SVM models, which are adopted for our forecast. Finally, the extremely high prices are considered as the consequence of bidding strategies by the market players. Those speculative behaviors are unpredictable. Therefore, only the publicly historical price data are used to forecast the future prices in this thesis, as the natural correlation between the historical and future price data are believed.
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Short Term Forecasting Analysis for Municipal Water Demand

Short Term Forecasting Analysis for Municipal Water Demand

This study applies various methodologies to estimate models of water demand in El Paso, Texas, and compares the short-run forecasting accuracy of each model. The LTF ARIMA parameter estimates indicate that a 10 % rate increase will lead to a 3.2 % decline in water demand after a lag of three months. Impulse response functions generated using the VAR model also suggests that prices negatively impact demand after a multi-month lag. These outcomes imply that price increases can serve as an instrument for controlling the growth of water consumption in El Paso. However, the results also indicate that the full effect of rate changes may not be felt immediately as price information is typically gleaned from bills for water already consumed. Furthermore, consumers in El Paso appear to react rather quickly, within one month, to changing weather conditions. Thus, in the event of a severe drought, it is likely that non-price conservation measures such as public information campaigns will be needed in addition to appropriate price signals in order to rapidly curtail water use.
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Modelling and forecasting short-term electricity load: a two step methodology

Modelling and forecasting short-term electricity load: a two step methodology

This section reports the forecasting results for both the TLSAR and DASARIMA models. One of the most used measure of forecasting accuracy in the load fore- casting literature is the Mean Absolute Percentage Error (MAPE) (see [39] and [35]), which measures the pro- portionality between the error and the observed load. An important point deserves attention. Several authors (see, for example, [39]) achieve MAPEs as low as 2% when predicting the total daily load, but results of different models cannot be compared on different datasets because of the differences among load curves in different countries. For example, a load profile of a country with tropical weather, such as Brazil, is distinct from one like USA or United Kingdom. Hence, if different datasets are used, the same model(s) must be used, and the comparison should be made among data sets and not models. If the researcher wants to compare the performance of different models, the same data with the same forecasting period must be used.
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Univariate versus Multivariate Models for Short-term Electricity Load Forecasting

Univariate versus Multivariate Models for Short-term Electricity Load Forecasting

Literature on short-term load forecast show numerous experiments using sta- tistical and computational intelligence methods. These methods may be applied to uni- variate models, in which the load is written as a linear function of the past loads and usually forecast by time series techniques [2], or multivariate, which also consider the effects of so called exogenous variables, such as social, economic and, mainly, weather- related (air temperature, wind speed, cloud covers, for example).

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Demand Forecasting in Deregulated Electricity Markets

Demand Forecasting in Deregulated Electricity Markets

A day ahead demand forecasting is essential for the efficient operation of electricity companies in the competitive electricity markets. Both the power producers and consumer needs single compact and robust demand forecasting tool for the efficient power system planning and execution. This research work proposes a day ahead short term demand forecasting for the competitive electricity markets using Artificial Neural Networks (ANNs). Historical demand data are collected for the month of January 2014 from PJM electricity markets. The work proposes the approach to reduce prediction error for electricity demands and aims to enhance the accuracy of next day electricity demand forecasting. Two types of demand forecasting models: classical forecasting and correlation forecasting models are proposed, explained and checked against each other. Proposed models are applied on real world case, PJM electricity markets for forecasting the demand on weekly working day, weekly off day and weekly middle day. The Mean Absolute Percentage Error (MAPE) for the two proposed models in the three respective cases is evaluated and analyzed. Results present that with all respects a day ahead demand forecasting through the correlation model are best and suitable for PJM electricity markets and produce less error with comparison of other classical models.
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Short-Term Price Forecasting Models Based on Artificial Neural Networks for Intraday Sessions in the Iberian Electricity Market

Short-Term Price Forecasting Models Based on Artificial Neural Networks for Intraday Sessions in the Iberian Electricity Market

Abstract: This paper presents novel intraday session models for price forecasts (ISMPF models) for hourly price forecasting in the six intraday sessions of the Iberian electricity market (MIBEL) and the analysis of mean absolute percentage errors (MAPEs) obtained with suitable combinations of their input variables in order to find the best ISMPF models. Comparisons of errors from different ISMPF models identified the most important variables for forecasting purposes. Similar analyses were applied to determine the best daily session models for price forecasts (DSMPF models) for the day-ahead price forecasting in the daily session of the MIBEL, considering as input variables extensive hourly time series records of recent prices, power demands and power generations in the previous day, forecasts of demand, wind power generation and weather for the day-ahead, and chronological variables. ISMPF models include the input variables of DSMPF models as well as the daily session prices and prices of preceding intraday sessions. The best ISMPF models achieved lower MAPEs for most of the intraday sessions compared to the error of the best DSMPF model; furthermore, such DSMPF error was very close to the lowest limit error for the daily session. The best ISMPF models can be useful for MIBEL agents of the electricity intraday market and the electric energy industry.
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An Overview of Electricity Demand Forecasting Techniques

An Overview of Electricity Demand Forecasting Techniques

Expert systems are new techniques that have emerged as a result of advances in the field of artificial intelligence. An expert system is a computer program that has the ability to reason, explain and have its knowledge base expanded as new information becomes available to it. To build the model, the ‘knowledge engineer’ extracts load forecasting knowledge from an expert in the field by what is called the knowledge base component of the expert system. This knowledge is represented as facts and IF-THEN rules, and consists of the set of relationships. Between the changes in the system load and changes in natural and forced condition factors that affect the use of electricity this rule base is used daily to generate the forecasts. Some of the rules do not change over time, while others have to be updated continually. The logical and syntactical relationships between weather load and the prevailing daily load shapes have been widely examined to develop different rules for different approaches. The typical variables in the process are the season under consideration, day of the week, the temperature and the change in this temperature. Illustrations of this method can be found in Rahman [31, 73] and Ho [63]. The algorithms of Rahman and Hazim [73] combine features from knowledge-based and statistical techniques, using the pairwise comparison technique to prioritize categorical variables. Brown [74] used a knowledge based load-forecasting approach that combines existing system knowledge, load growth patterns, and horizon year data to develop multiple load growth scenarios.
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Forecasting Macedonian GDP: Evaluation of different models for short term forecasting

Forecasting Macedonian GDP: Evaluation of different models for short term forecasting

We evaluate the forecasting performance of six different models for short-term forecasting of Macedonian GDP: 1) ARIMA model; 2) AR model estimated by the Kalman filter; 3) model that explains Macedonian GDP as a function of the foreign demand; 4) small structural model that links GDP components to a small set of explanatory variables; 5) static factor model that links GDP to the current values of several principal components obtained from a set of high-frequency indicators; 6) FAVAR model that explains GDP through its own lags and lags of the principal components. The comparison is done on the grounds of the Root Mean Squared Error and the Mean Absolute Error of the one-quarter- ahead forecasts. Results indicate that the static factor model outperforms the other models, providing evidence that information from large dataset can indeed improve the forecasts and suggesting that future efforts should be directed towards developing a state-of-the-art dynamic factor model. The simple model that links domestic GDP to foreign demand comes second, showing that simplicity must not be dismissed. The small structural model that explains every GDP component as a function of economic determinants comes third, “reviving” the interest in these old-school models, at least for the case of Macedonia.
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Weather Forecasting Using Merged Long Short-term Memory Model

Weather Forecasting Using Merged Long Short-term Memory Model

Weather forecasting to be addressed in this study can be categorized as a regression problem. To solve this problem, this study proposes LSTM model which is a deep learning model proposed by [13] and improved by [14]. The model has been succesfully used in many research fields such as: large scale image classification [20], video classification [21], natural language processing [22] anomaly detection [23], [24]. In this study, LSTM was used as a foundation for weather forecasting model because of several reasons mainly:(1) the model ability to solve long lag relationship in timeseries data (2) the model ability to address vanisihing gradient problem that commonly happen in training deep structure neural networks [13].
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