This study reviews the methods used to implement energy management systems (EnMS) in higher education institutions (HEIs) and their impact on improving energy performance considering their relationship with the requirements for an EnMS according to ISO 50001. From 2310 articles, 136 articles and 5 technical reports related to EnMS and energy efficiency were selected and analyzed. A synthesis of the major actions taken by HEIs to enhance their energy performance is presented, including energy management strategies, methods for measuring and estimating consumption, occupant behavior models that influence energy use, barriers to energy efficiency in HEIs buildings, and future challenges. It was found that studies on building energy management systems often do not incorporate an analysis of CO₂ emissions reduction. Funding for this research is driven by directives and policies related to energy performance. These results should assist HEIs seeking to implement an EnMS to improve their energy performance and reduce CO₂ emissions, thereby contributing to energy security, climate change mitigation, and fostering a new culture of energy use and consumption. It was also found that, although most studies do not explicitly mention the ISO 50001 standard, all of them comply with at least one of its requirements. Additionally, 27% of energy management strategies focus on operational aspects, while 26% involve energy audits, primarily through measurement, estimation, forecasting, energy reviews, and the establishment of an energy baseline (EnBL).

Stirling engines (SEs) have long attracted the attention of renewable energy researchers due to their external combustion design and flexibility in operating with various heat sources. The mathematical analysis of these devices is conducted by using a broad range of models ranging from basic zero-order to highly detailed fourth-order models, which are implemented through Computational Fluid Dynamics (CFD) simulations. The unique features of this last approach, combined with the increase in computing power, have promoted the use of CFD as a tool for analyzing SEs in recent years, significantly reducing the costs associated with prototype construction. However, Stirling CFD simulations are sophisticated due to the variety of physical phenomena involved, such as volume change, conjugated heat transfer, turbulent compressible fluid dynamics, and flow through porous media in the regenerator. Furthermore, there is currently no comprehensive review of CFD simulations of SEs in the literature; therefore, this contribution aims to fill that gap. Emphasis has been placed on identifying the type of engine, the physical phenomena modeled, the simplifying assumptions, and specific numerical aspects, such as mesh type, spatial and temporal discretization, and the order of the numerical schemes used. As a result, it has been found that in many cases, CFD numerical reports lack sufficient detail to ensure the reproducibility of the simulations. This work proposes guidelines for reporting CFD studies on Stirling engines to address this issue. Additionally, the need for a sufficiently detailed experimental benchmark database to validate future CFD studies is stressed. Finally, the use of Large Eddy Simulations on coupled key engine components—such as compression and expansion spaces, pistons, displacer, and regenerator—is suggested to provide further insights into the specific flow and heat transfer characteristics in Stirling engines.

Para se obter economia de energia por meio da melhoria da eficiência energética, é necessário fazer um diagnóstico que mostre o real desempenho energético e, assim, determinar os investimentos requeridos. Não obstante, a viabilidade econômica destes investimentos deve ser avaliada. Diversos autores afirmam que esta área é carente, especialmente na avaliação do risco. O payback é o critério mais utilizado, mas não é o mais conveniente. O objetivo deste trabalho é aplicar uma metodologia que envolve duas análises: a análise de engenharia e a análise de risco. A análise de engenharia é feita por meio do uso de ferramentas de diagnóstico que permitem identificar os investimentos em eficiência energética. A análise de risco permite avaliar sua viabilidade, considerando a incerteza associada às variáveis que determinam a economia de energia e seu efeito sobre estas, adaptando a metodologia EBaR® por meio da modelagem e simulação. A metodologia proposta foi aplicada em uma empresa do setor industrial brasileiro e permitiu identificar que a empresa pode diminuir o consumo não associado à produção em até 60%, e que o investimento proposto para melhorar a eficiência energética é viável, pois apresenta uma boa relação retorno-risco.

Renewable energy and energy efficiency are essential for a transition to cleaner and sustainable energy. Photovoltaic and wind turbine systems introduce operation, control, protection, and planning issues, particularly affecting frequency stability in the grid. In contrast to more widespread wind turbines and photovoltaic systems, biomass based electricity systems are more stable with no negative impacts on the grid stability. The efficiency of bagasse boilers is essential to guaranteeing adequate economic profit and environmental performance in sugar plants. To realize universal access to affordable, reliable, and modern energy services by 2030 (SDG 7), the use of renewable energy sources in energy mixing and energy efficiency must increase globally. Sugar plants include cogeneration systems to provide heat and electricity to the process and frequently sell an electricity surplus to the grid, which depends on their energy efficiency. Boilers are an essential component of cogeneration systems in sugar plants, and their efficiency is crucial to guarantee electricity surplus. Therefore, this study assessed a bagasse boiler to optimize its operational efficiency. To this end, the exergy assessment and multiobjective optimization based on a genetic algorithm are used. The results show that the exergy efficiency of the boiler improved by 0.8% with the optimization, reducing bagasse consumption by 23 t/d.

As a proposal to provide electricity for more than 2 million people in rural zones in Colombia, micro grids appears as a possible innovative solution. There are published research and projects designing micro grid that use renewable local energy resources with new features to make them affordable. However, some social and economic issues make them non-feasible. Thus, as a result of this research project, the aim of this paper is to present a model for micro grids for isolated rural areas. The modeling and simulation yields, energy demand and generation comparison, power flow analysis and the energy management system for this generic micro grid model modeled and simulated in Matlab-Simulink.

In the methodology proposed for this work an exergy analysis of a modern bagasse boiler, which operates as the main equipment of a cogeneration plant of 34 MW of a sugar mill north of the department of Valle del Cauca (Colombia) is performed. In this analysis the boiler is divided into seven blocks or functional units, which have their own operating conditions linked to the performance of the steam generator. Second Law balances can estimate the irreversibility in each of the defined blocks and, when added together these, total losses and exergy efficiency in the steam generator are obtained. The mathematical model developed allows, among other things, collating the values of temperatures of combustion gases through each heat exchange equipment from the actual data boiler. In addition, together with exergy analysis, the model allows a parallel with energy analysis. In this model, an important relationship with continuous boiler blowdown found. This is directly related to the quality of feed water and boiler operation, if these values come out of defined control, a considerable loss of efficiency occurs.