In order to research the advantages of usage of photovoltaic plants in smart grids, an analysis focused on the impact of photovoltaic systems on the stability and reliability of electrical grids is conducted in this paper. The paper addresses the technical aspects of integrating photovoltaic systems, including their variable production and how it affects the changes in electricity supply and demand in a real distributed power grid. Innovative technologies, such as energy storage devices and advanced communication systems, are also considered, which enable better control and management of the grid. The integration of a photovoltaic plant into a 20 kV network with consumers in the household and industrial categories, as well as an electric vehicle charging station, is analyzed with varying loads. The results obtained highlight the contribution of PV plants to the grid stability, reliability, voltage conditions, and total active and reactive power losses.

The resulting shift in load and generation profiles on the low voltage (LV) network poses new risks for distribution system operators (DSOs), including issues like congestion and power quality. To address these risks, two approaches are considered: traditional grid reinforcement or flexibility services. An emerging solution for harnessing flexibility is the development of local markets. This paper is focused on defining scenarios for testing the local market, considering different network conditions (load profiles, available capacity limits in the lines), different market clearing mechanisms, and bids. The LV network under study is a real Slovenian LV network in Luče, currently featuring 9 flexible households and one community battery, as part of the X-FLEX project (Horizon 2020, grant agreement n°863927). The second part involves testing these scenarios and conducting an analysis of the results, ensuring network constraints compliance through power flow simulation (using OpenDSS), and performing a technical analysis of the market design based on these results.

Energy production is one of the most crucial scientific, technological, economic, and political challenges in today's world. In response to the increasing demands of the European Union for reducing CO2 emissions and mitigating climate change, countries are obligated to align their national energy plans with clearly defined objectives, aiming for climate neutrality by 2050. This paper explores the location potential and optimal implementation of biomass power plants in Bosnia and Herzegovina. Biomass power plants, particularly those utilizing wood and plant biomass, are a promising solution for simultaneously reducing pollution, addressing unnecessary waste, and improving the energy efficiency of the systems where they are installed. The paper concludes that the potential of wood and plant biomass in Bosnia and Herzegovina remains underutilized. From an eco-perspective, the paper will also examine the reuse of large degraded areas in mines, where the fast-growing energy crops like Miscanthus could be planted.

The transition process from fossil fuels to environmentally friendly renewable energy sources carries the risk of creating new environmental damages. Photovoltaic technology represents one of the alternatives with the least risk of harmful environmental impact. However, this technology has two important drawbacks: the significant land occupation for the installation of PV systems and the uncontrollability of production. By constructing floating photovoltaic plants on hydroelectric reservoirs, both of these problems can be reduced to an acceptable level. Some artificial reservoirs, originally built for hydroelectric power plants, have acquired a significant secondary function as recreational areas and fish breeding sites. Therefore, there is justified resistance from the local community to change the existing appearance and purpose of such reservoirs. This paper proposes a completely new concept of integrating the interests of the local community into such objects. In addition to preserving existing uses, the concept also offers new features. This can make the entire system environmentally friendly and sustainable. This paper details the technology behind the construction of floating photovoltaic power plants on artificial reservoirs and emphasizes their various advantages. These benefits include the non-utilization of cultivable land, the ease of assembly and construction, integration into existing power grids, and the potential to address electricity storage issues. For instance, Buško Lake, covering an area of 55.8 km2, may host 2.93 km2 of installed floating photovoltaic (FPV) facilities, enabling a total installed capacity of 240 MW. With an average of 5.5 h of daily sunshine, this totals 2007 annual hours, equivalent to a 55 MW thermal power plant. An analysis showed that, with losses of 18.2%, the average annual production stands at 302 GWh, translating to an annual production value of 18 million € at 60 €/MWh. The integration of this production into an existing hydroelectric power plant featuring an artificial reservoir might boost its output by 91%. The available transmission line capacity of 237 MW is shared between the hydroelectric power plant (HPP) and FPV; hence during the FPV maximum power generation time, the HPP halts its production. HPP Orlovac operates a small number of hours annually at full capacity (1489 h); therefore in combination with the FPV, this number can be increased to 2852 h. This integration maintains the lake’s functions in tourism and fishing while expanding its capabilities without environmental harm.

Recognizing the increasing importance of renewable energy sources, specifically wind farms, in today's power environments, this paper aims to clarify the complex interactions between these renewable energy facilities and distribution grids functioning under low-demand conditions. This particular case comes with inherent limitations that must be considered by taking into account all the factors that can influence the performance of the wind farm under these conditions. The modelling procedure and the simulation of the connection of the wind farm to the power system in rural area was performed using EMTP-RV software. The mean annual production of the wind power plant and the behaviour of the wind power plant in the event of failure in a real power system were calculated. Also, the power quality was examined in agreement with the Network Code of the transmission system of Bosnia and Herzegovina.

Nearby lightning strokes are often considered as a prime source of transient overvoltages in the substations. Lightning overvoltages can cause unreliable operation of power system and power supply interruptions. Calculation of expected lightning overvoltages is necessary to design appropriate protection system. This paper presents the analysis of the lightning overvoltage performance of real 400 kV overhead transmission line and gas insulated substation (GIS), considering various factors, such as lightning stroke locations, peak currents, front rise times, etc. EMTP-RV software was used to model transmission line and substation elements and conduct simulations, while transmission line lightning performance was determined using Sigma Slp software. The expected overvoltages and surge arrester currents are calculated and used to design lightning protection system of the considered substation. Obtained results also indicate the importance of proper modelling of power system elements and lightning strokes.