Among the current challenges facing the energy sector is finding environmentally friendly and high-performance forms of energy generation. One such form of energy generation is from the wind. In addition to the fluctuations that cause changes in the generated energy, another factor that significantly affects the overall efficiency of wind farms is the distance between the turbines. In that context, a distance of at least three diameters (3D) onwards is necessary to enable a stable operation. This is more difficult to implement for mountainous terrain due to the terrain configuration’s influence, the turbine units’ positioning, and the mutual influence resulting from their position in the area under consideration. This work investigates the interdependence of the terrain features, the placement of ten turbines in different scenarios, and the impact on the overall efficiency of the wind farm. The place where the wind farm is considered is in Koznica, a mountainous area near Prishtina. An analysis has been carried out for two-diameter (2D), three-diameter (3D), and five-diameter (5D) turbine blade spacing for turbines with a rated power of 3.4 MW. The study considers placement in the following forms: Arc, I, L, M, and V. The results show that for 2D distance layout, the capacity factors for Arc, I, L, M, and V placements have the values: 32.9%, 29.8%, 31.1%, 30.6%, and 37.1%. For the 3D distance, according to these scenarios, the capacity factor values are: 29.9%, 30.8%, 30.4%, 29.3%, and 35.6%. For the longest distance, 5D, the capacity factor values are: 28.9%, 29.9%, 29.4%, 27.6%, and 30.6%. The value of the capacity factor for an optimal layout; is achieved at 39.3%.

Over time, the use of wind turbines has evolved in terms of the size and number of the turbines. The change in wind turbines comes as a result of major structural changes and then an increase in their production capacity. In the framework of the most stable operation for the surface of the terrain used in this study, a series of configurations have been proposed that are directly related to technical and economic sustainability. The complete scenarios will be realized in Koznica, where one-year measurements are done. In the framework of the realized scenarios, it can be seen that there is variability in terms of energy output from these configurations, which maximally comes from wake losses caused by the terrain. In cases where the scenarios with the addition of small turbines are studied, they, in the technical aspect, affect the increase in energy production, which, if those turbines were not installed, would not be applied. As an important part, the economic aspect of the realization of the previous optimization scenarios is analyzed by using Monte-Carlo simulation for LCOE analysis. Thus, it can be concluded that the analyzed scenarios with the addition of small turbines in the optimization process are more suitable and feasible for implementation.

The advantage of district heating systems compared to individual systems lies in their potential to diversify heat sources, foster greater system independence and reliability, and optimise heat energy production costs. This work evaluates the techno-economic rationale behind investing in district heating systems focusing on determining the threshold at which such investments become cost-effective. This includes indicators such as linear heat density (MWh/km) to ascertain the break-even point, alongside the calculation of the levelized sost of energy. Five simulation models of a heating system are developed and analysed for a designated area of the city of Ohrid (Republic of North Macedonia), focusing on existing buildings and their energy consumption patterns. Three scenarios incorporate public facilities such as schools, offices, and hospitals. Additionally, two more scenarios include these facilities along with 1000 residential buildings to achieve higher linear heat density. These buildings are examined both as energy class D structures with a demand of 110 kWh/m2 per year and as more efficient energy class C buildings with a heat demand of 70 kWh/m2 per year, including for space heating and domestic hot water supply. The energy hub system integrates various components, such as solar thermal collectors, combined heat and power, and heat pumps, to meet heat demands while ensuring a balanced energy mix. Scenario 5 is identified as the most cost-effective, with a levelized cost of energy of 98 EUR/MWh, a linear heat density of 1363 MWh/km, and an annual heat demand of approximately 15 GWh.

The decrease in conventional energy resources, environmental pollution issues and climate change are the leading factors inducing the increase of energy efficiency criteria. Trends to improve energy efficiency are mainly aimed at the construction sector as one of the leading sectors in energy consumption. In the paper the performance of the decentralized solar assisted heating systems (SAHS) for climatic conditions in Macedonia was analysed in order to assess its possibility to be integrated as part of the district heating system. The analysis is based on a holistic approach, in which the performance of the SAHS is generally functionally dependent on four factors: (1) the characteristics of each component, (2) the system structure and mutual interactions of the components, (3) the management method and (4) specific energy consumption for heating of the building. The specific analysis is directed toward the assessment of the solar fraction of the SAHS as a function of the building energy performance and system heating temperature range. The numerical modelling of the processes occurring in systems was performed with the dynamic simulation software TRNSYS. Both dynamic models of the solar bivalent system and reference building were developed. The dynamic model contributes to the flexibility of conducting parametric analysis. The obtained results from the parametric analysis were condensed in a general table upon which the analysis of system performance was performed.

Nowadays energy crises are characterized by their intensity, i.e. for a short period of time they can cause significant consequences on the economy and overall living. The impacts of energy crisis are mainly reflected indirectly through misbalance in electrical energy production, which is main component and foundation for all socio-economic processes. In addition, the current coincidence of the energy crisis (high price of natural gas) with the heating season reveals and emphasizes the importance of the heating energy. The aim of this paper is to analyse the role, advantages and disadvantages of existing district heating (DH) systems with cogeneration power plants CHP), as an important link in the country power system, especially in times of energy crises. In the analyses as a reference system is considered the DH system in Skopje, Republic of North Macedonia. Assessment for the influence of the fluctuation in heat consumption in the DH system on the power system is performed by using simulation software for energy modelling of the district heating system in Skopje, linked with the data for yearly (hourly basis) electricity consumption. Additional economic assessment is conducted to determine cost competitiveness of DH system with other individual heating technologies available in urban areas. Results reveal that district heating systems with cogeneration power plants in densely populated urban areas are cost optimal heating system and extremely important link in country energy chain, providing energy stability, along with potential consequences in case of longer (un) foreseen interruptions in operation.

The city of Skopje faces persistent inefficiencies in waste management, characterised by rising waste generation and limited progress in sustainable treatment solutions. This paper addresses the need for a structured approach to identify barriers to implementing Waste-to-Energy (WtE) technology, focusing on incineration-based energy recovery as a potential option for improving waste management while generating energy. Interpretive Structural Modelling (ISM) and Cross-Impact Matrix Multiplication Applied to Classification (MICMAC) were applied to six categories of implementation challenges: operational, technical, financial, regulatory, social, and environmental. ISM identified hierarchical relationships within each category, while MICMAC classified challenges according to their driving and dependence powers. The results revealed distinct structural patterns across categories, with underlying barriers including inadequate waste separation and collection, lack of integrated waste information, competitive renewable energy prices, regulatory preferences for waste reuse, recycling and reduction over WtE, institutional distrust, and combustion residue management. The findings reveal interconnected barriers with distinct structural roles, while conceptual mitigation measures and relevant SDG linkages are proposed based on the identified barriers and literature. The proposed ISM-MICMAC framework provides a structured approach for analysing WtE implementation barriers and can be adapted to other contexts following appropriate contextual and quantitative assessment.