Drying processes are among the most energy-intensive industrial processes. There is a need for development of the efficient methods needed for estimating, measuring, and reducing energy use. Different machine learning algorithms might provide some of the answers to these issues in a faster and less costly way, without the need for time-consuming and expensive experiments done at different scales of the dryers. The aim of this paper was to provide a comprehensive overview of machine learning applications for addressing energy-related challenges by exploration of different energy types and energy reduction opportunities. Also, the analysis of the applied algorithms, their specific applications and a critical evaluation of the obtained results are provided. The paper is based on the necessity of the improvements in energy use needed for drying related on the existing data. The overview of the ways for such achievements, and a general classification of machine learning algorithm are the background of the paper. The methods used are the machine learning techniques employed in different energy-related issues for drying processes. The paper focuses on the applications of artificial neural networks and other machine learning algorithms and models for different energy-related issues, including different energy types applications, challenges associated with energy consumption, and opportunities for energy reduction. Not only the applied algorithms, but also their specific applications, and the statistical analysis of the obtained results are also overviewed. Finally, a critical evaluation of the findings highlighting the potentials of machine learning algorithms in addressing energy-related challenges (such as estimation of energy consumption, opportunities for energy reduction, and use of different energy sources) is provided. The presented analysis underscored the effectiveness of machine learning applications for these purposes.

A building energy performance gap can be illustrated as the difference between the theoretical (methodologically defined) and the actual energy consumption. In EU countries, Energy Performance Certificates are issued when buildings are constructed, sold, or leased. This information is the first step in order to evaluate the energy performance of the building stock. In Serbia, when issuing an energy certificate, the adopted national methodology recognizes only energy consumption for heating. The main purpose of this paper is to evaluate the energy gap and estimate the relevance of an Energy Performance Certificate to meet the national energy efficiency or carbon target. An Energy Performance Certificate determines the theoretical residential and commercial building energy efficiency or its “design intent”. This research stresses the necessity of measuring and achieving reductions in actual energy consumption through system regulation and consumers’ self-awareness in buildings. The research compares the performance of the building stock (135) that is connected to the District Heating System (DHS), with its own integrated heat meter, to Individual Gas Boiler (IGB) systems (18), in the city of Novi Sad, Serbia, built after 2014. For the purpose of comparing energy consumption, 16 buildings were selected that are very similar in terms of design, operation, and location. The data used are derived from metered consumption data, official evidence of city service companies, and Energy Performance Certificates of the considered buildings. We have determined that IGB systems have a much wider specific annual performance gap (11.19–101 kWh/m²a) than the buildings in the DHS (3.16–18.58 kWh/m²a).

This paper provide a qualitative analysis of existing metrics that directly or indirectly quantify energy justice. The main objective of the paper was to determine shortcomings and to suggest improvements in order to enhance existing metrics and create conditions for defining of new energy indicators. The emphasis was placed on the analysis of the energy transition readiness. Therefore, elements of the energy trilemma of the observed countries were defined using known parameters related to the transition processes. The use of known economic, political, energy, environmental, and other indicators provided the universality of the suggested metric and reduced the impact of subjectivity. Proposed improve?ments for the metric of energy justice and the defining of new energy indicators served as a help tool for decision-makers in the energy sector. Political solutions should strive to a balancing of the energy trilemma, which was the main precon?dition for achieving the goals of sustainable development and a just transition. The main results of this paper are the possibility of universal application of metric for the quantification of energy justice and a new composite indicator that indicated the level of energy transition fairness.

The aim of this paper is to analyze and explore the most suitable energy policy instruments for energy efficiency improvement in Serbia. The analysis has been carried out with a focus on energy indicators for Serbia and EU27. It encompasses a period of twenty-two years and is directed towards the consideration of amendments that need to be made in the National Energy Efficiency Policy. Despite constant attempts to improve and increase energy efficiency and to expand utilization of renewable energy sources, it seems that accomplished results are still very modest. The comparative analysis of the situation in the area of energy efficiency in Serbia and in the EU takes into consideration deficiencies in the energy policy in Serbia and proposed measures for overcoming them. The Multiple Criteria Decision Analysis method is used for analyzing the extent of key influences on success in the implementation of energy efficiency policy in Serbia and also for the interpretation of results. The analysis shows that identified energy policy instruments are such that the success in their implementation will depend on a reformed institutional approach. This method can be applied in any other country.

In the heating system of residential and commercial buildings, heating substation has an important role because it is used as a separator between primary and secondary supply sides. In this paper, we focused on the development of the simulation model of all heating substation elements, which influence the change of relevant parameters: water temperature, flow, and pressure. The primary objective of the paper is to analyze and develop mathematical models of the heat exchanger, control valve, three-way valve and frequency-regulated centrifugal pump that are configurable and generic as much as possible, so they can be used for the development of the model that could operate in real time. A real-time model could be used as a suitable replacement for an actual physical system in the process of testing and improvement of the control system performance. Different elements setups of district heating substation are considered, and the modelbased simulation is presented for one of them.