Meeting the global demand for aquatic products while maintaining sustainability is a critical challenge. This review article examines global practices of land-based aquaculture systems that could be implemented in the EU, as the EU has not yet fully realized its potential in developing the aquaculture sector. Therefore, the article examines different aspects (aquaculture systems, technological solutions and improvements, and best management practices) in achieving sustainable aquaculture and emphasizes the need for innovation and cooperation in the face of increasing environmental concerns and resource constraints. There is no one-size-fits-all solution for the sustainable intensification of aquaculture. The way forward requires a combination of different and improved-upon technological solutions complemented by technological innovation and better management practices. The sustainability of aquaculture requires a broader application of the ecosystem approach to aquaculture and the promotion of energy and resource efficiency measures in aquaculture systems.

The main aim of this study is to evaluate the results achieved by implementation of different support policies in form of subsidies for energy efficiency improvements and transition to renewable energy sources. The article compares the energy efficiency measures in district heating systems with other support program. In order to assess the effectiveness of implementation of different renewable energy technologies and energy efficiency projects, the levelized costs of saved energy for different support programs were determined. Authors compared different co-financed projects related to replacement of fossil fuel energy sources in district heating (mainly to biomass) and the installation of new biomass boilers, heat pumps, solar collectors and other local technologies in municipal buildings. Results show that financial support for energy efficiency measures in industrial enterprises and district heating systems has been most cost-effective, mainly due to the low co-financing rate (30%) and the high potential for energy savings in different production processes. Authors have identified the blind-spots within the funding allocation for different municipalities, which is not always dedicated to achieved energy savings.

Biomass is an essential pillar of the bioeconomy as it serves as its main resource. Biomass energy plays an important role in energy sector. According to long wave theory, a sharp breakthrough in biotechnology is due over the next few years. As the price for energy wood increases, wood as a resource will not be sustainable in energy sector. In the case of Latvia, the price of energy wood as a resource is predicted to increase from 0.04 EUR/kWh to 0.12 EUR/kWh per unit of energy.

A vital component of achieving climate neutrality in the future involves bolstering energy efficiency measures in educational institutions and improving the overall knowledge on sustainable solutions. To achieve fruitful outcomes, the active involvement of various stakeholders, such as managers, teaching staff, and students, is indispensable. By implementing energy-efficient building systems, advancing the use of renewable energy sources, and incorporating sustainable practices into the curriculum, educational institutions can decrease their environmental impact and conserve resources for future generations. Active participation from all stakeholders, including managers, teaching staff, and students, is essential for the success of these efforts. Providing students with a comprehensive education on sustainability equips them to apply this knowledge in their future professions, thus contributing to a more sustainable society. To gain insights into the existing state of sustainability within educational systems, a comprehensive study of educational institutions was undertaken. To assess and compare schools’ sustainability, a composite indicator was developed. The study’s findings reveal that the implementation of mandatory and optional measures can lead to a substantial reduction in primary energy consumption by 39% and greenhouse gas emissions by 34% in educational institutions. The average abandonment costs for mandatory measures are 5.87 EUR/kgCO₂/year, but the average value for optional measures is 33.80 EUR/kgCO₂/year. It is suggested demonstration projects be implemented in institutions where specialists in RE, mechatronics, building engineering systems, and environmental technologies are trained by showcasing technologies needed for the transition to climate neutrality.

This study is dedicated to the analysis of the drying process energy consumption. In order to evaluate the main energetic processes that consume the most energy, the energy consumption of each individual drying process with and without air recirculation was modelled. The model shows that drying agent (air) recirculation is not an energy-saving operation, since it increases the total electricity and heat consumption. Recirculation of the drying agent increases the moisture content of the drying agent at the dryer entrance, which increases the need for fresh air in the dryer so that it can absorb the evaporating moisture from the dried material. An increased flow of the drying agent in the dryer increases the heat and electricity consumption.

This article examines energy audit procedures as a crucial instrument for raising building and business energy efficiency in European Union (EU) Member States. Energy audits, which include technical, economic, and environmental aspects, are essential to reaching the EU’s climate targets, which include increasing energy independence and cutting emissions by 55% by 2030. The study highlights how crucial energy efficiency initiatives are to combating climate change, cutting energy use, and advancing sustainable development. A thorough examination of methods, financing sources, and legislative frameworks reveals differences in how Member States carry out directives such as the Energy Performance of Buildings Directive and the Energy Efficiency Directive. A case study on Latvia is included in the article, highlighting the country’s energy audit regulations, implementation difficulties, and successes. This study applied a bibliographic methodology or review of the scientific and other relevant literature, analyzing sources identified through targeted keyword searches in academic databases and a variety of online sources, including official legal websites, handbooks, reports, plans, and other publicly available digital resources. The integration of energy efficiency principles and country performances are compared using data from the Odyssee and Mure databases. The results highlight how important it is to standardize energy auditing practices, promote information sharing across national borders, and move past obstacles like public resistance and budgetary limitations. Policy recommendations to improve energy efficiency and aid the EU’s transition to climate neutrality by 2050 are included in the research’s conclusion.