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This study investigates the implementation of passive design strategies to improve the thermal environment in the extremely hot climates of Brazil, Portugal, and Turkey. Given the rising cooling demands due to climate change, optimizing energy efficiency in buildings is essential. Using the Trace 3D Plus v6.00.106 software, typical residential buildings for each country were simulated to assess various passive solutions, such as building orientation, wall and roof modifications, glazing optimization options, window-to-wall ratio (WTWR) reduction, shading, and natural ventilation. The findings highlight that Brazil experienced the higher discomfort temperatures compared to Mediterranean climates, with indoor air temperatures exceeding 28 °C all year round and remaining between 34 °C and 37 °C for nearly 40% of the time. Building orientation had a minimal impact near the equator, while Mediterranean climates benefited from an up to 10% variation in energy demand. Thermal insulation combined with white exterior paint resulted in Şanlıurfa experiencing annual energy savings of up to 26%. Optimal roof solutions yielded a 19% demand reduction in Évora, while WTWR reduction and double-colored glazing achieved up to a 35% reduction in Évora and 19% in other regions. Combined strategies achieved energy demand reductions of 44% for Évora, 40% for Şanlıurfa, and 32% for Teresina. The study emphasizes the need for integrated, climate-specific passive solutions, showing their potential to enhance both energy efficiency and the thermal environment in residential buildings across diverse hot climates.

This research aims to optimize and compare the annual costs of energy services in buildings with critical loads and analyze case studies for hospitals and higher education institutions in the United States. Besides electricity and natural gas costs, the study considers all the infrastructure costs of capital amortization and maintenance. In addition, it studies energy resilience improvement due to distributed generation, including solar photovoltaic, solar thermal, internal combustion engine, and fuel cell sources. The optimization considers the electrical consumption, the heating and cooling demands, and the operational strategy of the energy storage systems. To simulate real scenarios, energy tariffs were modeled and considered, and final optimization results were produced. Some of the microgrid load was considered critical to model resilience benefits. The results show that if favorable energy tariffs are applied, the benefits of increasing energy resilience represent a novel market with high potential in facilities with significant critical loads. This methodology can be used in similar scenarios, adapting each particular load profile and critical load to provide a combined optimal solution regarding resilience and economic benefits.

Several heritage cities face the need to modernize public lighting systems that are installed on the facades of buildings. The legal obstacles to intervene in heritage infrastructures create a different scenario than other cities. This circumstance raises the question if it is possible to install a modern, innovative lighting system, isolated from the electrical distribution system. This research analyzes the feasibility of modernizing the system using 304 mini photovoltaic generation plants, implementing a novel lighting system control process that indirectly uses sky brightness measurements based on current research at the Catholic University of Cuenca. As a case study, the Historic Center of the City of Cuenca-Ecuador, a World Heritage Site, whose system is made up of 1,252 luminaires, is analyzed. The results conclude that it is feasible to modernize the lighting service with the adoption of the proposed technologies and for control, a novel system based on indirect measurement of sky clarity has been developed. Finally, the political implications are analyzed in the framework of energy efficiency and modernization of the systems, as well as the recommendation to the political decision-makers. The study can be replicated in other cities of the world with similar characteristics.

This research analyzes the impact of a hybrid off-grid renewable energy system consisting of wind turbines, solar photovoltaic, hydrokinetic turbines and battery-backed to provide a group of novel airplane-shaped buildings, generates development in nearby towns that sit on a city vantage point from Cuenca in Ecuador. This is an innovative proposal that, in addition to using renewable energy in the complex of buildings, generates development in nearby towns. Three sources of renewable energy under energy control, load cycle and load monitoring are used to determine new patterns in the behavior of the sources with respect to the demand for electricity. Above all, it reduces carbon. With the support of HOMER Pro, the generation sources are optimized to cover the electrical demand patterns of the group of buildings in the form of airplanes. The results show that the systems that include solar panels, wind and hydrokinetic generators have a higher cost but there is more guarantee by maintaining their charge levels in the batteries above 40%. The proposed methodology and design can be widely adapted to places with similar characteristics worldwide, creating a novel solution for this type of buildings powered by renewable energy. The annual energy required by the set of buildings is 234.86 MW h/year. When projecting the renewable energy system for 25 years, an NPC of $37,600 and a COE of $0.386/kWh are achieved.

Climate-change-related events are increasing the costs of power outages, including losses of product, revenue, and productivity. Given the increase in meteorological disasters in recent years related to climate change effects, the number of costly blackouts, from an economic perspective, has increased in a directly proportional manner. As a result, there is increasing interest in the use of alternators to supply dependable, instantaneous, and uninterruptible electricity. Traditional research has focused on the installation of diesel backup systems to ensure power requirements without deeply considering the resilience capabilities of systems, which is the ability of a system to recover or survive adversity, such as a power outage. This research presents a novel approach focusing on the resiliency impact of backup systems’ storage-free dispatchable solutions on buildings and compares the advantages and disadvantages of biomethane microturbines, natural gas engines, and diesel engines backup systems, discussing the revenue resulting from the resilience provided by emergency generators. The results show that, for several diesel fuel and natural gas safety assumptions, natural gas alternators have a lower probability of failure at the time of a blackout than diesel generators, and therefore, resilience increases.

The authors of this paper analyze the use of biogas-powered micro-Combined Heat and Power (micro-CHP) systems for residential microgrids to enhance their resilience during blackouts. With the increasing frequency of natural disasters, ensuring power system reliability has become a critical concern. Microgrids can provide a solution to this problem by integrating distributed energy resources and operating them independently of the grid. The authors of this paper investigate the design and implementation of biogas-powered micro-CHP systems for residential microgrids. The paper concludes with a discussion of the potential of biogas-powered micro-CHP systems as a key component of resilient and sustainable energy systems in the future.

This research presents a 100% renewable energy (RE) scenario by 2050 with a high share of electric vehicles on the grid (V2G) developed in Ecuador with the support of the EnergyPLAN analysis tool. Hour-by-hour data iterations were performed to determine solutions among various features, including energy storage, V2G connections that spanned the distribution system, and long-term evaluation. The high participation in V2G connections keeps the electrical system available; meanwhile, the high proportions of variable renewable energy are the pillar of the joint electrical system. The layout of the sustainable mobility scenario and the high V2G participation maintain the balance of the electrical system during most of the day, simplifying the storage equipment requirements. Consequently, the influence of V2G systems on storage is a significant result that must be considered in the energy transition that Ecuador is developing in the long term. The stored electricity will not only serve as storage for future grid use. Additionally, the V2G batteries serve as a buffer between generation from diversified renewable sources and the end-use stage.

The combined cycle plants in 2019 are upswing due to definitive closure of conventional coal-fired power plants. The price increase of a ton of CO2, will close to 25 euros in 2019, could allow to increase their capacity factor above 50%. It has been already achieved a high flexibility imposed by the regulator of the Spanish network and possible hybridizations, in both gas turbine and heat recovery steam generator. Therefore, one step ahead directed to the reduction and treatment of the flow of exhaust gases at the outlet of the boiler during the operation is necessary.An optimization study based on a parametric analysis of this possible reduction has been carried out, with recirculation of the exhaust gases and the treatment of them with amines in a CO2 capture plant, both at the exit of the boiler, using real data base, to study their possible integration within the existing combined cycle.The results obtained are very promising: firstly, with the use a 35% of exhaust gases recirculation + capture plant in existing combined cycle, the efficiency of the gas turbine improves 0.5%. Secondly, the total number of tons of CO2 avoid per year would be around 633 kilotons (based on a capacity factor in 2019 closed to 0.41). Therefore, the saved cost in ton of CO2 for one existing combined cycle could be around 21.4 million of euros/year. This configuration, therefore, decreases the number of trains from 2 (existing combined cycle + capture plant) to 1.36. This decreasing is traduced in costs reduction and due to it an effective technique for pollutant emissions reduction.On the other hand, the new combined cycle will have an efficiency penalty caused by chemical absorption in the capture plant. The crossover requires approximately 30% of the middle/low steam of the turbine to obtaining 90% capture of CO2 with the corresponding penalty of 4 points in the global cycle performance and a reduction of power close to 21% with respect to the existing cycle. All boil down to a conflict of interests between €/Mw lost vs €/ton CO2avoided. Clearly the rising in capacity factor and flexibility in current combined cycle plants will be decisive in future to elucidate this conflict. The results obtained are totally in contrast with other studies carried out being fully feasible for implementation in existing combined cycles.

Climate change conditions in the last decades have derived in a significant reduction of rivers’ levels, irregularity of rainfall and, thus, difficulties in accessing to drinkable water. This situation is especially dramatical in islanded environments, such as the Canary Islands in Spain, where these restrictions to water resources have conducted to an overexploitation of aquifers and wells, with the deterioration of the environment that this fact entails. For this reason, desalination plants have become essential, and efforts must be done to reduce their impact and costs, as the involved processes for water desalination are high energy intensive. In this research paper, an optimized size hybrid wind and solar photovoltaic power plant is proposed to feed a desalination plant under the approach of not only feed the desalination process, but also provide the power grid with clean energy, taken advantage of the surplus electricity production. This way, not only the water resources stress is mitigated (through the desalting water production), but also the grid benefits from the integration of a distributed renewable energy source (DRES). Moreover, the business model is improved as the cost of drinkable water production is reduced and the power plant owner receives extra incomes from the water sales. Optimization results for a case study in Gran Canaria island shows that, considering the power dispatch in the island, the remuneration limits for power delivery and the remuneration for provided water, the optimal DRES associated with a desalination plant providing 5600 m3/day of desalted water and a maximum annual electricity injection to the power grid of 5.88 GWh/year, an hybrid solar PV and wind generation installation with electrochemical storage is a feasible solution that makes the Levelized Cost of Electricity (LCOE) achieve a singular reduced value despite considering the additional costs of the desalination plant, although financial help must be provided to reduce the Payback Time. Keywords: Water stress, Desalination, Renewable energy, Solar photovoltaics, Wind energy, Hybrid power plant

Energy Intensive Industries (EII) are high users of energy and some of these facilities are extremely dependent on Natural Gas for processing heat production. In European countries, where Natural Gas is mostly imported from external producers, the increase in international Natural Gas prices is making it difficult for some industries to deliver the required financial results. Therefore, they are facing complex challenges that could cause their delocalization in regions with lower energy costs. European countries lack on-site Natural Gas resources and the plans to reduce greenhouse gas emissions in the industrial sector make it necessary to find an alternative. Many different processes cannot be electrified, and in these cases, synthetic methane is one of the solutions and also represents an opportunity to reduce external energy supply dependency. This study analyzes the current development of power-to-gas technological solutions that could be implemented in large industrial consumers to produce Synthetic Methane using Green Hydrogen as a raw source and using Renewable Energy electricity mainly produced with photovoltaic or wind energy. The study also reviews the triple bottom line impact and the current development status and associated costs for each key component of a power-to-gas plant and the requirements to be fulfilled in the coming years to develop a cost-competitive solution available for commercial use.

Energy policy is becoming a key aspect of the everyday worldwide agenda, and the decisions in this field are directly affecting many aspects, such as energy security, energy supply, and consumer final prices, as well as environmental aspects, among others, and will also affect conditions in the coming years with regard to aspects such as energy resource availability decay, climate change effects, or air contamination. During the last decades, many specific efforts in energy planning research have been carried out by different scientists around the world, but very few of their scientifically based conclusions and recommendations have been transferred into energy planning and energy policy. As a consequence, the energy availability and the environmental situation of the world are worsening; the objectives which aim to achieve a maximum of a 1.5 °C increase are far from being achieved, and many different regions are suffering energy supply disruptions and lack of accessible and secure energy access. This paper analyzes how current energy policy is based more on the direct influence of stakeholders, energy politics, and citizens’ beliefs or preferences than on a scientific approach. It also proposes a different approach that would combine scientific energy planning as a driver for stakeholders and the political decisions which are necessary to consider as soon as possible; this is the only possible way to ensure a sustainable future.

Energy efficiency is becoming one of the key research topics in the energy field and has, therefore, attracted extensive attention in recent research [...]

The energy flows of the double skin, glass-glass façades have been analysed, establishing a mathematical model to determine the energy savings provided by this construction solution in 10 cities in Spain. It has been found that the two climatological variables that most influence energy savings are outdoor temperature, as it is directly related to the demand for heating, and solar irradiation, as it is the source of energy from which savings are extracted. Energy savings in winter vary between 11.1% and 20.5%, depending on the weather. A linear relationship between the annual average outdoor temperature and the useful energy provided by the double- skin façade has been determined. It was verified that the maximum energy saving occurs when the façade is offset a few degrees to the east from the pure south orientation. It deviates further east, the higher the annual average temperature. A linear relationship has been established between the outside temperature and the azimuth of the façade with which the maximum energy saving occurs. To obtain savings percentages greater than 20%, the ratio between the double-skin façade surface and the total heated surface of the building must be less than 7.

In order to eradicate water–energy–food poverty, Sustainable Development Goals (SDG) proposed milestones to overcome the feeding problem. The development of water–energy–food (WEF) nexus management tools, and approaches has increased during last years. The aim of this research is to review WEF nexus management methods, tools, and examples to identify gaps, goals, or future development that arise when modelling goods management issues for designing a sustainable development framework. It is also presented the food–biofuel competition for resources problem focusing in threatened systems. In addition to the resource trade-off quantification issue, it proposed an analysis for WEF systems management from economic, environmental, and practical points of view with the aim of identifying results, challenges, gaps, or assumptions for nexus. The renewable energy highlights as an enabler for sustainable development.

This research presents a novel optimization strategy for concentrating solar power (CSP) plants with thermal energy storage (TES) systems that aims to stabilize and reduce electricity prices in spot markets. In the current international scenario of initiatives with regulatory changes aiming to reduce climate change effects and therefore CO2 emissions, many countries are reducing the fossil fuel share in their respective electrical systems and increasing electrical renewable energy systems. These carbon free generation systems have inherent problems such as their intermittence which, combined with the lack of high-scale energy storage systems, cause a stability risk in electrical grid systems and require conventional fuel systems to match demand and production. In this research, we analyze spot price markets using a marginal price system that relies on natural gas and is quite sensitive to an increase in fuel prices, causing a direct increase in the final energy cost in systems with a high renewable energy share, and we study how optimally sized CSP plants with TES can be used as manageable solar energy systems and contribute to both price and grid stability. For the Spanish market, we analyze the ongoing market situation and generation mix and we present an optimization scheme using the System Advisor Model (SAM) software that aims to maximize energy availability throughout the day and contribute to peak generation. The results show that the optimization strategy increases the profitability of CSP plants but also ensures a contribution to spot price stability and reduction. A sensibility analysis is presented, and a case study is analyzed in southern Spain. The results show the importance of optimized CSP plants in an energy transition and a strategy is proposed that can be extended to other locations worldwide.

Energy consumption in the transport sector and buildings are of great concern. This research aims to quantify how eco-routing, eco-driving and eco-charging can increase the amount of energy available for vehicle-to-building. To do this, the working population was broken into social groups (freelancers, local workers and commuters) who reside in two cities with different climate zones (Alcalá de Henares-Spain and Jaén-Spain) since the way of using electric vehicles is different. An algorithm based on the Here® application program interface and neural networks was implemented to acquire data of the stochastic usage of EVs of each social group. Finally, an increase in the amount of energy available for vehicle-to-building was assessed thanks to the algorithm. The results per day were as follows. Owing to the algorithm proposed a reduction ranging from 0.6 kWh to 2.2 kWh was obtained depending on social groups. The proposed algorithm facilitated an increase in energy available for vehicle-to-building ranging from 13.2 kWh to 33.6 kWh depending on social groups. The results show that current charging policies are not compatible with all social groups and do not consider the renewable energy contribution to the total electricity demand.

Yearly, EU-28 conventional thermal generating plants reject a greater amount of energy than what ultimately is utilised by residential and commercial loads for heating and hot water. If this waste heat were to be used through district heating networks, given a previous energy valorisation, there would be a noticeable decrease in imported fossil fuels for heating. As a consequence, benefits in the form of an energy efficiency increase, an energy security improvement, and a minimisation of emitted greenhouse gases would occur. Given that it is not expected for heat demand to decrease significantly in the medium term, district heating networks show the greatest potential for the development of cogeneration. However, to make this happen, some barriers that are far from being technological but are mostly institutional and financial need to be removed. The purpose of this review is to provide information on the potential of using waste heat from conventional thermal power plants (subsequently converted into cogeneration plants) in district heating networks located in the EU-28. For this, a preliminary assessment is conducted in order to show an estimate of the cost of adopting an energy strategy in which district heating networks are a major player of the energy mix. From this assessment, it is possible to see that even though the energy strategy proposed in this paper, which is based on a dramatic increase in the joint use of district heating networks and cogeneration, is capital-intensive and would require an annual investment of roughly 300 billion euros, its adoption would result in a reduction of yearly fuel expenses in the order of 100 billion euros and a shortening of about 15% of the total final energy consumption, which makes it of paramount interest as an enabler of the legal basis of the “Secure, Clean and Efficient Energy” future enacted by the EU-28 Horizon 2020.

In this research, the modeling, simulation, and analysis of the energy conversion equations that describe the behavior of a hybrid photovoltaic and wind turbine system that supplies electrical energy to an average organic architecture is performed. Organic constructions have a philosophy that seeks to understand and integrate into the site, taking advantage of the natural potentials and their resources of the surrounding areas so that they form part of a unified and correlated composition. The rooms in these buildings are designed similar to a bean, inspired by the uterus of a mother and her child who are comfortable, at rest, and alive. We are left with the task of spreading this research to integrate its energy potential from the surroundings and transform it into autonomous electrical energy. In this article, a numerical model based on the fundamental equations was developed and coded, and the results compared with experimental data with a real airplane-type system located in a remote area of Ecuador. The model is intended to be used as an optimization and design tool for such hybrid systems applied to organic constructions. After an error analysis it was determined that this model predicted quite interesting results compared to the experimental data under various conditions. It is important to indicate that this analysis has been carried out so that in the future, these power generation systems can be exploited and applied more efficiently in areas far from the public electricity grid.

Designing eco-friendly products involves energy efficiency improvements. Eco-friendly products must consider not only raw materials and manufacturing processes to improve energy efficiency but also energy needed when designing them. This research shows how eco-routing (ER), eco-charging (EC), eco-driving (EDR), vehicle-to-grid (V2G) and electric vehicles (EVs) can contribute to the reduction of energy consumption during product design. To do this, a group of 44 engineers assigned to the project was chosen to assess the total energy available for V2G when driving EVs from their homes to the design center by using ER, ED and EC by running an application coded by the authors. The energy stored in EVs was used to quantify the reduction in energy consumption of the buildings present in the design center. The results show that the energy saving ranges from 2.89% to 6.9% per day—in other words, 93 kWh per day during the design process. In addition, the fact of making the design process greener implies that renewable energies (REs) are integrated better during the design process. By running the application, drivers are informed about the RE mix when the charging process takes place. Finally, this research shows that current policies make V2G and vehicle-to-home techniques not compatible.

This research work aims at a multinational study in Europe of the emissions and energy costs generated by the operation of low enthalpy geothermal systems, with heat pumps fed by different energy sources. From an economic point of view, natural gas and biogas prices are, usually, lower than electricity ones. So it may be advantageous to use these energy sources to feed the heat pumps instead of electricity. From the environmental point of view, it is intended to highlight the fact that under certain conditions of electricity production (electricity mix), more CO2 emissions are produced by electricity consumption than using other a priori less “clean” energy sources such as natural gas. To establish the countries where each of the different heat pumps may be more cost-efficient and environmentally friendly, data from multi-source geospatial databases have been collected and analyzed. The results show that in the majority of cases, the electric heat pump is the most recommendable solution. However, there are some geographic locations (such as Poland and Estonia), where the gas engine heat pump may be a better alternative.

The goal of the research is to assess the minimum requirement of fast charging infrastructure to allow country-wide interurban electric vehicle (EV) mobility. Charging times comparable to fueling times in conventional internal combustion vehicles are nowadays feasible, given the current availability of fast charging technologies. The main contribution of this paper is the analysis of the planning method and the investment requirements for the necessary infrastructure, including the definition of the Maximum Distance between Fast Charge (MDFC) and the Basic Highway Charging Infrastructure (BHCI) concepts. According to the calculations, distance between stations will be region-dependent, influenced primarily by weather conditions. The study considers that the initial investment should be sufficient to promote the EV adoption, proposing an initial state-financed public infrastructure and, once the adoption rate for EVs increases, additional infrastructure will be likely developed through private investment. The Spanish network of state highways is used as a case study to demonstrate the methodology and calculate the investment required. Further, the results are discussed and quantitatively compared to other incentives and policies supporting EV technology adoption in the light-vehicle sector.

This article examines the main market barriers that hamper the introduction of geothermal energy at local, national, and European levels as well as the necessary steps that need to be taken to eradicate them, thus contributing to the general use of this renewable source of energy. The novelty of this study lies in the detailed description of four different scenarios: the European Union (EU), Spain, the Canary Islands, and the agricultural sector for the three types of geothermal energies and their uses: Low-enthalpy or thermal uses, high-enthalpy or electrical uses and renewable energy mix. The results are expected to differ in terms of level of introduction, barriers, and measures to be taken. We have selected Spain within the European context due to its meagre 0.1% geothermal market share in primary demand for renewable energy, and the Canary Islands in particular, given its insular nature. We have likewise picked the agricultural sector due to its underdevelopment as far as renewable energies are concerned, including geothermal energy.