Crop residues could provide a local, sustainable, and low-cost solid fuel alternative to woody biomass for heat supply in the agricultural community. However, utilization of crop residues on a small scale is associated with increased pollutant emissions, as well as ash-related operational problems. There is ongoing research on fuel conditioning measures, such as fuel leaching, fuel blending, and using mineral additives, as a manner to mitigate these issues. The purpose of this study is to investigate the applicability of additives in the combustion of crop residues under everyday conditions. To this end, wheat straw pellets were combusted in a 30 kW boiler with and without additives (kaolinite and MgO, 2 wt. % and 4 wt. %). Carbon monoxide (CO) and particulate matter (PM) emissions have been monitored during combustion experiments, as well as changes in bottom ash behavior and composition. The results have shown that additives slightly decrease the heating value of the fuel (3%–6%). During experiments with additized wheat straw pellets, higher emissions of CO were observed. Combustion of pure not additized wheat straw pellets resulted in a PM emission of 568 mg/Nm³, which decreased with additives. Both researched additives increase the four characteristic ash deformation temperatures.

Renewable and distributed energy systems could provide a solution to the burning issue of reliable and clean supply of energy, having in mind current state and future predictions for population growth and fossil fuel scarcity. Hybrid renewable energy systems are novelty in Serbia and warrant further detailed research. The aim of this paper is to analyze the application of renewable energy sources(RES) for electricity and heat supply of a typical household in Serbia, as well as the cost-effectiveness of the proposed system. The influence of feed-in tariff change on the value of the investment is analyzed. Small, grid-connected hybrid system (for energy supply of a standard household), consisting of geothermal heat pump for heating/cooling, solar photovoltaic panels and small wind turbine for power supply is analyzed as a case study. System analysis was conducted with the help of RETScreen software. Results of techno-economics analysis have shown that investing in geothermal heat pump and photovoltaic panels is cost-effective, while that is not the case with small wind turbine.

Wave energy is of interest for regions with high wave power potential, as well as for regions with modest wave power potential such as the Adriatic/Mediterranean coastlines and islands. In the present paper, the possibility of integrating a wave power farm with the power system of an island in the Adriatic Sea, combining the wave power with a battery energy storage system (BESS) and solar photovoltaics (PVs) is explored and its impact on the local weak low voltage grid is investigated. The load profile is typical of the demand (consumption) of an Adriatic island, in which the demand substantially increases during summer (the tourist season). The wave power technology is a point-absorbing wave energy converter (WEC) with a direct drive linear permanent-magnet synchronous generator power take-off device. Wave power farms (WPFs) consist of two to ten WECs. In this study, we show that the integration of a WPF consisting of two WECs into the grid is optimal and helps to reach zero grid exchange, and a BESS reduces the intermittency of the power flow into the grid. Since a potential wave power farm is to be installed in a populated recreational area, the technical study is complemented by discussion on cross-cutting aspects such as its environmental and social impact.

The paper provides a comprehensive examination of resources available for the deployment of green hydrogen in Serbia. The assessment encompasses various aspects, including renewable energy potentials, technological advancements, and future projections. The evaluation considers factors such as solar and wind power capacities, which are pivotal for green hydrogen production. Additionally, the study delves into the policy landscape, addressing initiatives aimed at fostering the integration of green hydrogen into Serbia's energy matrix. The analysis combines quantitative data on energy production capacities with qualitative insights into the economic and environmental implications of green hydrogen utilization. While the nation boasts abundant renewable energy resources, challenges such as high production costs and infrastructure limitations hinder widespread adoption. However, with strategic initiatives and technological advancements, Serbia can overcome these hurdles and pave the way for a sustainable hydrogen economy. Assessing Serbia's green hydrogen potential, driven by over 24 095 MWp from solar and 10 750 MWp from wind, highlights the nation's capacity to harness renewable resources, with hydrogen production set to grow from 1915 tons in 2019 to 37 ,123 tons by 2040. The findings aim to contribute to the ongoing discourse on sustainable energy transitions and the role of green hydrogen in Serbia's evolving energy landscape.