Due to the fast increase in the world population, the need for the energy and water increases rapidly. Various studies have been made to meet this extra energy and water demand. Most of these studies have focused on solar energy and solar driven desalination systems. Solar water desalination is a well-known and proven technique which has been used for a long time at remote areas and places suffering from shortage of potable quality water. In this study, a flat plate solar collector-assisted water distillation system was designed and tested under actual conditions and its energy and exergy efficiencies were analyzed, which is the main contribution of this study to the literature related to solar desalination systems. The system works under closed cycle in order to prevent efficiency losses caused by internal fouling in both solar collector and distillation unit. The maximum daily energy efficiency of the system was obtained as 48.1% and the maximum exergy efficiency was found as 2.76% for optimum flow rate values.

The conventional distillation processes, such as multi effect evaporation, reverse osmosis, and electro dialysis, are not only energy intensive but also are uneconomical for small demands of fresh water. However, developments in the use of solar energy have shown that it is ideally suited for desalination, when the demand of fresh water is not so much. Distillation is one of the important methods of getting clean water from brackish and sea water using the free energy supply from the sun. A vacuum tube solar collector-assisted solar water distillation system was designed and tested under actual conditions of Turkey. This study is the first to use vacuum tube solar collectors in distillation systems. As expected, the vacuum tube solar collector increased the fresh water generation. Additionally, a mathematical model is presented and compared with experimental results. The model gives a good match with experimental values.

The increasing environmental challenges posed by the widespread use of fossil fuels and the fluctuating nature of renewable energy have driven the need for more efficient and sustainable energy solutions. Current research is actively exploring hybrid energy systems as a means to address these issues. One such area of focus is the integration of Organic Rankine Cycles (ORCs) with gas and steam turbines, utilizing both natural gas (NG) and solar parabolic trough collectors (PTCs) as energy sources. This study examines the performance of a hybrid system implemented in Kirkuk, Iraq, a region known for its substantial solar radiation. Previous research has shown that hybrid systems can effectively enhance energy conversion efficiency and reduce environmental impacts, but there is still a need to assess the specific benefits of such systems in different geographical and operational contexts. The analysis reveals a thermal efficiency of 59.32% and an exergy efficiency of 57.28%. The exergoeconomic analysis highlights the optimal energy cost at USD 71.93/MWh when the compressor pressure ratio is set to 8 bar. The environmental assessment demonstrates a significant reduction in ${\mathrm{C}\mathrm{O}}_2$/emissions, with a carbon footprint of 316.3 kg ${\mathrm{C}\mathrm{O}}_2$/MWh at higher compressor pressure ratios. These results suggest that integrating solar energy with natural gas can substantially improve electricity generation while being both cost-effective and environmentally sustainable.